diff --git a/.gitignore b/.gitignore
index b1020b8..833ef3b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -114,6 +114,7 @@
 /git-read-tree
 /git-rebase
 /git-rebase--am
+/git-rebase--helper
 /git-rebase--interactive
 /git-rebase--merge
 /git-receive-pack
diff --git a/.mailmap b/.mailmap
index ab59b2f..e06526a 100644
--- a/.mailmap
+++ b/.mailmap
@@ -177,6 +177,7 @@
 Pascal Obry <pascal@obry.net> <pascal.obry@gmail.com>
 Pascal Obry <pascal@obry.net> <pascal.obry@wanadoo.fr>
 Pat Notz <patnotz@gmail.com> <pknotz@sandia.gov>
+Patrick Steinhardt <ps@pks.im> <patrick.steinhardt@elego.de>
 Paul Mackerras <paulus@samba.org> <paulus@dorrigo.(none)>
 Paul Mackerras <paulus@samba.org> <paulus@pogo.(none)>
 Peter Baumann <waste.manager@gmx.de> <Peter.B.Baumann@stud.informatik.uni-erlangen.de>
diff --git a/.travis.yml b/.travis.yml
index 9c63c8c..591cc57 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -39,6 +39,27 @@
 
 matrix:
   include:
+    - env: Linux32
+      os: linux
+      services:
+        - docker
+      before_install:
+        - docker pull daald/ubuntu32:xenial
+      before_script:
+      script:
+        - >
+          docker run
+          --interactive
+          --env DEFAULT_TEST_TARGET
+          --env GIT_PROVE_OPTS
+          --env GIT_TEST_OPTS
+          --env GIT_TEST_CLONE_2GB
+          --volume "${PWD}:/usr/src/git"
+          daald/ubuntu32:xenial
+          /usr/src/git/ci/run-linux32-build.sh $(id -u $USER)
+        # Use the following command to debug the docker build locally:
+        # $ docker run -itv "${PWD}:/usr/src/git" --entrypoint /bin/bash daald/ubuntu32:xenial
+        # root@container:/# /usr/src/git/ci/run-linux32-build.sh
     - env: Documentation
       os: linux
       compiler: clang
diff --git a/Documentation/RelNotes/2.12.1.txt b/Documentation/RelNotes/2.12.1.txt
new file mode 100644
index 0000000..a74f7db
--- /dev/null
+++ b/Documentation/RelNotes/2.12.1.txt
@@ -0,0 +1,41 @@
+Git v2.12.1 Release Notes
+=========================
+
+Fixes since v2.12
+-----------------
+
+ * Reduce authentication round-trip over HTTP when the server supports
+   just a single authentication method.  This also improves the
+   behaviour when Git is misconfigured to enable http.emptyAuth
+   against a server that does not authenticate without a username
+   (i.e. not using Kerberos etc., which makes http.emptyAuth
+   pointless).
+
+ * Windows port wants to use OpenSSL's implementation of SHA-1
+   routines, so let them.
+
+ * Add 32-bit Linux variant to the set of platforms to be tested with
+   Travis CI.
+
+ * When a redirected http transport gets an error during the
+   redirected request, we ignored the error we got from the server,
+   and ended up giving a not-so-useful error message.
+
+ * The patch subcommand of "git add -i" was meant to have paths
+   selection prompt just like other subcommand, unlike "git add -p"
+   directly jumps to hunk selection.  Recently, this was broken and
+   "add -i" lost the paths selection dialog, but it now has been
+   fixed.
+
+ * Git v2.12 was shipped with an embarrassing breakage where various
+   operations that verify paths given from the user stopped dying when
+   seeing an issue, and instead later triggering segfault.
+
+ * The code to parse "git log -L..." command line was buggy when there
+   are many ranges specified with -L; overrun of the allocated buffer
+   has been fixed.
+
+ * The command-line parsing of "git log -L" copied internal data
+   structures using incorrect size on ILP32 systems.
+
+Also contains various documentation updates and code clean-ups.
diff --git a/Documentation/RelNotes/2.13.0.txt b/Documentation/RelNotes/2.13.0.txt
new file mode 100644
index 0000000..5c2348d
--- /dev/null
+++ b/Documentation/RelNotes/2.13.0.txt
@@ -0,0 +1,297 @@
+Git 2.13 Release Notes
+======================
+
+Backward compatibility notes.
+
+ * Use of an empty string as a pathspec element that is used for
+   'everything matches' is still warned and Git asks users to use a
+   more explicit '.' for that instead.  The hope is that existing
+   users will not mind this change, and eventually the warning can be
+   turned into a hard error, upgrading the deprecation into removal of
+   this (mis)feature.  That is not scheduled to happen in the upcoming
+   release (yet).
+
+ * The historical argument order "git merge <msg> HEAD <commit>..."
+   has been deprecated for quite some time, and will be removed in a
+   future release.
+
+
+Updates since v2.12
+-------------------
+
+UI, Workflows & Features
+
+ * "git describe" and "git name-rev" have been taught to take more
+   than one refname patterns to restrict the set of refs to base their
+   naming output on, and also learned to take negative patterns to
+   name refs not to be used for naming via their "--exclude" option.
+
+ * Deletion of a branch "foo/bar" could remove .git/refs/heads/foo
+   once there no longer is any other branch whose name begins with
+   "foo/", but we didn't do so so far.  Now we do.
+
+ * When "git merge" detects a path that is renamed in one history
+   while the other history deleted (or modified) it, it now reports
+   both paths to help the user understand what is going on in the two
+   histories being merged.
+
+ * The <url> part in "http.<url>.<variable>" configuration variable
+   can now be spelled with '*' that serves as wildcard.
+   E.g. "http.https://*.example.com.proxy" can be used to specify the
+   proxy used for https://a.example.com, https://b.example.com, etc.,
+   i.e. any host in the example.com domain.
+
+ * "git tag" did not leave useful message when adding a new entry to
+   reflog; this was left unnoticed for a long time because refs/tags/*
+   doesn't keep reflog by default.
+
+ * The "negative" pathspec feature was somewhat more cumbersome to use
+   than necessary in that its short-hand used "!" which needed to be
+   escaped from shells, and it required "exclude from what?" specified.
+
+ * The command line options for ssh invocation needs to be tweaked for
+   some implementations of SSH (e.g. PuTTY plink wants "-P <port>"
+   while OpenSSH wants "-p <port>" to specify port to connect to), and
+   the variant was guessed when GIT_SSH environment variable is used
+   to specify it.  The logic to guess now applies to the command
+   specified by the newer GIT_SSH_COMMAND and also core.sshcommand
+   configuration variable, and comes with an escape hatch for users to
+   deal with misdetected cases.
+
+ * The "--git-path", "--git-common-dir", and "--shared-index-path"
+   options of "git rev-parse" did not produce usable output.  They are
+   now updated to show the path to the correct file, relative to where
+   the caller is.
+
+ * "git diff -W" has been taught to handle the case where a new
+   function is added at the end of the file better.
+
+ * "git update-ref -d" and other operations to delete references did
+   not leave any entry in HEAD's reflog when the reference being
+   deleted was the current branch.  This is not a problem in practice
+   because you do not want to delete the branch you are currently on,
+   but caused renaming of the current branch to something else not to
+   be logged in a useful way.
+
+ * "Cc:" on the trailer part does not have to conform to RFC strictly,
+   unlike in the e-mail header.  "git send-email" has been updated to
+   ignore anything after '>' when picking addresses, to allow non-address
+   cruft like " # stable 4.4" after the address.
+   (merge 9d3343961b jh/send-email-one-cc later to maint).
+
+ * When "git submodule init" decides that the submodule in the working
+   tree is its upstream, it now gives a warning as it is not a very
+   common setup.
+   (merge d1b3b81aab sb/submodule-init-url-selection later to maint).
+
+ * "git stash save" takes a pathspec so that the local changes can be
+   stashed away only partially.
+   (merge 9e140909f6 tg/stash-push later to maint).
+
+ * Documentation for "git ls-files" did not refer to core.quotePath.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * The code to list branches in "git branch" has been consolidated
+   with the more generic ref-filter API.
+
+ * Resource usage while enumerating refs from alternate object store
+   has been optimized to help receiving end of "push" that hosts a
+   repository with many "forks".
+
+ * The gitattributes machinery is being taught to work better in a
+   multi-threaded environment.
+
+ * "git rebase -i" starts using the recently updated "sequencer" code.
+
+ * Code and design clean-up for the refs API.
+
+ * The preload-index code has been taught not to bother with the index
+   entries that are paths that are not checked out by "sparse checkout".
+
+ * Some warning() messages from "git clean" were updated to show the
+   errno from failed system calls.
+
+ * The "parse_config_key()" API function has been cleaned up.
+   (merge ad8c7cdadd jk/parse-config-key-cleanup later to maint).
+
+ * A test that creates a confusing branch whose name is HEAD has been
+   corrected not to do so.
+   (merge f0252ca23c jk/t6300-cleanup later to maint).
+
+ * The code that parses header fields in the commit object has been
+   updated for (micro)performance and code hygiene.
+   (merge b072504ce1 rs/commit-parsing-optim later to maint).
+
+ * An helper function to make it easier to append the result from
+   real_path() to a strbuf has been added.
+   (merge 33ad9ddd0b rs/strbuf-add-real-path later to maint).
+
+ * Reduce authentication round-trip over HTTP when the server supports
+   just a single authentication method.  This also improves the
+   behaviour when Git is misconfigured to enable http.emptyAuth
+   against a server that does not authenticate without a username
+   (i.e. not using Kerberos etc., which makes http.emptyAuth
+   pointless).
+   (merge 40a18fc77c jk/http-auth later to maint).
+
+ * Windows port wants to use OpenSSL's implementation of SHA-1
+   routines, so let them.
+   (merge 2cfc70f0de jh/mingw-openssl-sha1 later to maint).
+
+ * The t/perf performance test suite was not prepared to test not so
+   old versions of Git, but now it covers versions of Git that are not
+   so ancient.
+   (merge 28e1fb5466 jt/perf-updates later to maint).
+
+ * Add 32-bit Linux variant to the set of platforms to be tested with
+   Travis CI.
+   (merge 88dedd5e72 js/travis-32bit-linux later to maint).
+
+ * "git branch --list" takes the "--abbrev" and "--no-abbrev" options
+   to control the output of the object name in its "-v"(erbose)
+   output, but a recent update started ignoring them; fix it before
+   the breakage reaches to any released version.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.12
+-----------------
+
+Unless otherwise noted, all the fixes since v2.9 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * "git repack --depth=<n>" for a long time busted the specified depth
+   when reusing delta from existing packs.  This has been corrected.
+   (merge 42b766d765 jk/delta-chain-limit later to maint).
+
+ * The code to parse the command line "git grep <patterns>... <rev>
+   [[--] <pathspec>...]" has been cleaned up, and a handful of bugs
+   have been fixed (e.g. we used to check "--" if it is a rev).
+   (merge 131f3c96d2 jk/grep-no-index-fix later to maint).
+
+ * "git ls-remote" and "git archive --remote" are designed to work
+   without being in a directory under Git's control.  However, recent
+   updates revealed that we randomly look into a directory called
+   .git/ without actually doing necessary set-up when working in a
+   repository.  Stop doing so.
+   (merge 4b0c3c7735 jn/remote-helpers-with-git-dir later to maint).
+
+ * "git show-branch" expected there were only very short branch names
+   in the repository and used a fixed-length buffer to hold them
+   without checking for overflow.
+   (merge d3cc5f4c44 jk/show-branch-lift-name-len-limit later to maint).
+
+ * A caller of tempfile API that uses stdio interface to write to
+   files may ignore errors while writing, which is detected when
+   tempfile is closed (with a call to ferror()).  By that time, the
+   original errno that may have told us what went wrong is likely to
+   be long gone and was overwritten by an irrelevant value.
+   close_tempfile() now resets errno to EIO to make errno at least
+   predictable.
+   (merge 7e8c9355b7 jk/tempfile-ferror-fclose-confusion later to maint).
+
+ * "git remote rm X", when a branch has remote X configured as the
+   value of its branch.*.remote, tried to remove branch.*.remote and
+   branch.*.merge and failed if either is unset.
+   (merge 20690b2139 rl/remote-allow-missing-branch-name-merge later to maint).
+
+ * A "gc.log" file left by a backgrounded "gc --auto" disables further
+   automatic gc; it has been taught to run at least once a day (by
+   default) by ignoring a stale "gc.log" file that is too old.
+   (merge a831c06a2b dt/gc-ignore-old-gc-logs later to maint).
+
+ * The code to parse "git -c VAR=VAL cmd" and set configuration
+   variable for the duration of cmd had two small bugs, which have
+   been fixed.
+   (merge 1274a155af jc/config-case-cmdline-take-2 later to maint).
+
+ * user.email that consists of only cruft chars should consistently
+   error out, but didn't.
+   (merge 94425552f3 jk/ident-empty later to maint).
+
+ * "git upload-pack", which is a counter-part of "git fetch", did not
+   report a request for a ref that was not advertised as invalid.
+   This is generally not a problem (because "git fetch" will stop
+   before making such a request), but is the right thing to do.
+   (merge bdb31eada7 jt/upload-pack-error-report later to maint).
+
+ * A leak in a codepath to read from a packed object in (rare) cases
+   has been plugged.
+   (merge 886ddf4777 rs/sha1-file-plug-fallback-base-leak later to maint).
+
+ * When a redirected http transport gets an error during the
+   redirected request, we ignored the error we got from the server,
+   and ended up giving a not-so-useful error message.
+   (merge 8e27391a5f jt/http-base-url-update-upon-redirect later to maint).
+
+ * The patch subcommand of "git add -i" was meant to have paths
+   selection prompt just like other subcommand, unlike "git add -p"
+   directly jumps to hunk selection.  Recently, this was broken and
+   "add -i" lost the paths selection dialog, but it now has been
+   fixed.
+   (merge c852bd54bd jk/add-i-patch-do-prompt later to maint).
+
+ * Git v2.12 was shipped with an embarrassing breakage where various
+   operations that verify paths given from the user stopped dying when
+   seeing an issue, and instead later triggering segfault.
+   (merge ce83eadd9a js/realpath-pathdup-fix later to maint).
+
+ * There is no need for Python only to give a few messages to the
+   standard error stream, but we somehow did.
+   (merge b8686c661d ss/remote-bzr-hg-placeholder-wo-python later to maint).
+
+ * The code to parse "git log -L..." command line was buggy when there
+   are many ranges specified with -L; overrun of the allocated buffer
+   has been fixed.
+   (merge aaae0bf787 ax/line-log-range-merge-fix later to maint).
+
+ * The command-line parsing of "git log -L" copied internal data
+   structures using incorrect size on ILP32 systems.
+   (merge 07f546cda5 vn/line-log-memcpy-size-fix later to maint).
+
+ * "git diff --quiet" relies on the size field in diff_filespec to be
+   correctly populated, but diff_populate_filespec() helper function
+   made an incorrect short-cut when asked only to populate the size
+   field for paths that need to go through convert_to_git() (e.g. CRLF
+   conversion).
+   (merge 12426e114b jc/diff-populate-filespec-size-only-fix later to maint).
+
+ * A few tests were run conditionally under (rare) conditions where
+   they cannot be run (like running cvs tests under 'root' account).
+   (merge c6507484a2 ab/cond-skip-tests later to maint).
+
+ * "git branch @" created refs/heads/@ as a branch, and in general the
+   code that handled @{-1} and @{upstream} was a bit too loose in
+   disambiguating.
+   (merge fd4692ff70 jk/interpret-branch-name later to maint).
+
+ * "git fetch" that requests a commit by object name, when the other
+   side does not allow such an request, failed without much
+   explanation.
+   (merge d56583ded6 mm/fetch-show-error-message-on-unadvertised-object later to maint).
+
+ * "git filter-branch --prune-empty" drops a single-parent commit that
+   becomes a no-op, but did not drop a root commit whose tree is empty.
+   (merge 32da7467eb dp/filter-branch-prune-empty later to maint).
+
+ * Recent versions of Git treats http alternates (used in dumb http
+   transport) just like HTTP redirects and requires the client to
+   enable following it, due to security concerns.  But we forgot to
+   give a warning when we decide not to honor the alternates.
+   (merge 5cae73d5d2 ew/http-alternates-as-redirects-warning later to maint).
+
+ * "git push" had a handful of codepaths that could lead to a deadlock
+   when unexpected error happened, which has been fixed.
+   (merge d1a13d3fcb jk/push-deadlock-regression-fix later to maint).
+
+ * Other minor doc, test and build updates and code cleanups.
+   (merge 2cfa83574c mm/two-more-xstrfmt later to maint).
+   (merge b803ae4427 ps/docs-diffcore later to maint).
+   (merge bcd886d897 ew/markdown-url-in-readme later to maint).
+   (merge b2d593a779 rj/remove-unused-mktemp later to maint).
+   (merge 3255e512a8 jk/ewah-use-right-type-in-sizeof later to maint).
diff --git a/Documentation/config.txt b/Documentation/config.txt
index 015346c..eccc012 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -334,6 +334,10 @@
 	crawlers and some backup systems).
 	See linkgit:git-update-index[1]. True by default.
 
+core.splitIndex::
+	If true, the split-index feature of the index will be used.
+	See linkgit:git-update-index[1]. False by default.
+
 core.untrackedCache::
 	Determines what to do about the untracked cache feature of the
 	index. It will be kept, if this variable is unset or set to
@@ -350,16 +354,19 @@
 	all fields, including the sub-second part of mtime and ctime.
 
 core.quotePath::
-	The commands that output paths (e.g. 'ls-files',
-	'diff'), when not given the `-z` option, will quote
-	"unusual" characters in the pathname by enclosing the
-	pathname in a double-quote pair and with backslashes the
-	same way strings in C source code are quoted.  If this
-	variable is set to false, the bytes higher than 0x80 are
-	not quoted but output as verbatim.  Note that double
-	quote, backslash and control characters are always
-	quoted without `-z` regardless of the setting of this
-	variable.
+	Commands that output paths (e.g. 'ls-files', 'diff'), will
+	quote "unusual" characters in the pathname by enclosing the
+	pathname in double-quotes and escaping those characters with
+	backslashes in the same way C escapes control characters (e.g.
+	`\t` for TAB, `\n` for LF, `\\` for backslash) or bytes with
+	values larger than 0x80 (e.g. octal `\302\265` for "micro" in
+	UTF-8).  If this variable is set to false, bytes higher than
+	0x80 are not considered "unusual" any more. Double-quotes,
+	backslash and control characters are always escaped regardless
+	of the setting of this variable.  A simple space character is
+	not considered "unusual".  Many commands can output pathnames
+	completely verbatim using the `-z` option. The default value
+	is true.
 
 core.eol::
 	Sets the line ending type to use in the working directory for
@@ -1402,6 +1409,12 @@
 	Make `git gc --auto` return immediately and run in background
 	if the system supports it. Default is true.
 
+gc.logExpiry::
+	If the file gc.log exists, then `git gc --auto` won't run
+	unless that file is more than 'gc.logExpiry' old.  Default is
+	"1.day".  See `gc.pruneExpire` for more ways to specify its
+	value.
+
 gc.packRefs::
 	Running `git pack-refs` in a repository renders it
 	unclonable by Git versions prior to 1.5.1.2 over dumb
@@ -1919,7 +1932,10 @@
   must match exactly between the config key and the URL.
 
 . Host/domain name (e.g., `example.com` in `https://example.com/`).
-  This field must match exactly between the config key and the URL.
+  This field must match between the config key and the URL. It is
+  possible to specify a `*` as part of the host name to match all subdomains
+  at this level. `https://*.example.com/` for example would match
+  `https://foo.example.com/`, but not `https://foo.bar.example.com/`.
 
 . Port number (e.g., `8080` in `http://example.com:8080/`).
   This field must match exactly between the config key and the URL.
@@ -1954,6 +1970,17 @@
 matched against are those given directly to Git commands.  This means any URLs
 visited as a result of a redirection do not participate in matching.
 
+ssh.variant::
+	Depending on the value of the environment variables `GIT_SSH` or
+	`GIT_SSH_COMMAND`, or the config setting `core.sshCommand`, Git
+	auto-detects whether to adjust its command-line parameters for use
+	with plink or tortoiseplink, as opposed to the default (OpenSSH).
++
+The config variable `ssh.variant` can be set to override this auto-detection;
+valid values are `ssh`, `plink`, `putty` or `tortoiseplink`. Any other value
+will be treated as normal ssh. This setting can be overridden via the
+environment variable `GIT_SSH_VARIANT`.
+
 i18n.commitEncoding::
 	Character encoding the commit messages are stored in; Git itself
 	does not care per se, but this information is necessary e.g. when
@@ -2827,6 +2854,31 @@
 	The default set of branches for linkgit:git-show-branch[1].
 	See linkgit:git-show-branch[1].
 
+splitIndex.maxPercentChange::
+	When the split index feature is used, this specifies the
+	percent of entries the split index can contain compared to the
+	total number of entries in both the split index and the shared
+	index before a new shared index is written.
+	The value should be between 0 and 100. If the value is 0 then
+	a new shared index is always written, if it is 100 a new
+	shared index is never written.
+	By default the value is 20, so a new shared index is written
+	if the number of entries in the split index would be greater
+	than 20 percent of the total number of entries.
+	See linkgit:git-update-index[1].
+
+splitIndex.sharedIndexExpire::
+	When the split index feature is used, shared index files that
+	were not modified since the time this variable specifies will
+	be removed when a new shared index file is created. The value
+	"now" expires all entries immediately, and "never" suppresses
+	expiration altogether.
+	The default value is "2.weeks.ago".
+	Note that a shared index file is considered modified (for the
+	purpose of expiration) each time a new split-index file is
+	either created based on it or read from it.
+	See linkgit:git-update-index[1].
+
 status.relativePaths::
 	By default, linkgit:git-status[1] shows paths relative to the
 	current directory. Setting this variable to `false` shows paths
diff --git a/Documentation/diff-format.txt b/Documentation/diff-format.txt
index cf52626..706916c 100644
--- a/Documentation/diff-format.txt
+++ b/Documentation/diff-format.txt
@@ -78,9 +78,10 @@
 :100644 100644 5be4a4...... 000000...... M file.c
 ------------------------------------------------
 
-When `-z` option is not used, TAB, LF, and backslash characters
-in pathnames are represented as `\t`, `\n`, and `\\`,
-respectively.
+Without the `-z` option, pathnames with "unusual" characters are
+quoted as explained for the configuration variable `core.quotePath`
+(see linkgit:git-config[1]).  Using `-z` the filename is output
+verbatim and the line is terminated by a NUL byte.
 
 diff format for merges
 ----------------------
diff --git a/Documentation/diff-generate-patch.txt b/Documentation/diff-generate-patch.txt
index d2a7ff5..231105c 100644
--- a/Documentation/diff-generate-patch.txt
+++ b/Documentation/diff-generate-patch.txt
@@ -53,10 +53,9 @@
 The <mode> is included if the file mode does not change; otherwise,
 separate lines indicate the old and the new mode.
 
-3.  TAB, LF, double quote and backslash characters in pathnames
-    are represented as `\t`, `\n`, `\"` and `\\`, respectively.
-    If there is need for such substitution then the whole
-    pathname is put in double quotes.
+3.  Pathnames with "unusual" characters are quoted as explained for
+    the configuration variable `core.quotePath` (see
+    linkgit:git-config[1]).
 
 4.  All the `file1` files in the output refer to files before the
     commit, and all the `file2` files refer to files after the commit.
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index d91ddbd..89cc0f4 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -192,10 +192,9 @@
 	given, do not munge pathnames and use NULs as output field terminators.
 endif::git-log[]
 +
-Without this option, each pathname output will have TAB, LF, double quotes,
-and backslash characters replaced with `\t`, `\n`, `\"`, and `\\`,
-respectively, and the pathname will be enclosed in double quotes if
-any of those replacements occurred.
+Without this option, pathnames with "unusual" characters are quoted as
+explained for the configuration variable `core.quotePath` (see
+linkgit:git-config[1]).
 
 --name-only::
 	Show only names of changed files.
diff --git a/Documentation/git-apply.txt b/Documentation/git-apply.txt
index 8ddb207..631cbd8 100644
--- a/Documentation/git-apply.txt
+++ b/Documentation/git-apply.txt
@@ -108,10 +108,9 @@
 	When `--numstat` has been given, do not munge pathnames,
 	but use a NUL-terminated machine-readable format.
 +
-Without this option, each pathname output will have TAB, LF, double quotes,
-and backslash characters replaced with `\t`, `\n`, `\"`, and `\\`,
-respectively, and the pathname will be enclosed in double quotes if
-any of those replacements occurred.
+Without this option, pathnames with "unusual" characters are quoted as
+explained for the configuration variable `core.quotePath` (see
+linkgit:git-config[1]).
 
 -p<n>::
 	Remove <n> leading slashes from traditional diff paths. The
diff --git a/Documentation/git-branch.txt b/Documentation/git-branch.txt
index 28d46cc..092f1bc 100644
--- a/Documentation/git-branch.txt
+++ b/Documentation/git-branch.txt
@@ -12,7 +12,7 @@
 	[--list] [-v [--abbrev=<length> | --no-abbrev]]
 	[--column[=<options>] | --no-column]
 	[(--merged | --no-merged | --contains) [<commit>]] [--sort=<key>]
-	[--points-at <object>] [<pattern>...]
+	[--points-at <object>] [--format=<format>] [<pattern>...]
 'git branch' [--set-upstream | --track | --no-track] [-l] [-f] <branchname> [<start-point>]
 'git branch' (--set-upstream-to=<upstream> | -u <upstream>) [<branchname>]
 'git branch' --unset-upstream [<branchname>]
@@ -253,6 +253,11 @@
 --points-at <object>::
 	Only list branches of the given object.
 
+--format <format>::
+	A string that interpolates `%(fieldname)` from the object
+	pointed at by a ref being shown.  The format is the same as
+	that of linkgit:git-for-each-ref[1].
+
 Examples
 --------
 
diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index 4f8f20a..25dcdcc 100644
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt
@@ -117,9 +117,12 @@
 
 -z::
 --null::
-	When showing `short` or `porcelain` status output, terminate
-	entries in the status output with NUL, instead of LF. If no
-	format is given, implies the `--porcelain` output format.
+	When showing `short` or `porcelain` status output, print the
+	filename verbatim and terminate the entries with NUL, instead of LF.
+	If no format is given, implies the `--porcelain` output format.
+	Without the `-z` option, filenames with "unusual" characters are
+	quoted as explained for the configuration variable `core.quotePath`
+	(see linkgit:git-config[1]).
 
 -F <file>::
 --file=<file>::
diff --git a/Documentation/git-describe.txt b/Documentation/git-describe.txt
index e4ac448..8755f3a 100644
--- a/Documentation/git-describe.txt
+++ b/Documentation/git-describe.txt
@@ -83,7 +83,20 @@
 --match <pattern>::
 	Only consider tags matching the given `glob(7)` pattern,
 	excluding the "refs/tags/" prefix.  This can be used to avoid
-	leaking private tags from the repository.
+	leaking private tags from the repository. If given multiple times, a
+	list of patterns will be accumulated, and tags matching any of the
+	patterns will be considered. Use `--no-match` to clear and reset the
+	list of patterns.
+
+--exclude <pattern>::
+	Do not consider tags matching the given `glob(7)` pattern, excluding
+	the "refs/tags/" prefix. This can be used to narrow the tag space and
+	find only tags matching some meaningful criteria. If given multiple
+	times, a list of patterns will be accumulated and tags matching any
+	of the patterns will be excluded. When combined with --match a tag will
+	be considered when it matches at least one --match pattern and does not
+	match any of the --exclude patterns. Use `--no-exclude` to clear and
+	reset the list of patterns.
 
 --always::
 	Show uniquely abbreviated commit object as fallback.
diff --git a/Documentation/git-filter-branch.txt b/Documentation/git-filter-branch.txt
index 0a09698..6e4bb02 100644
--- a/Documentation/git-filter-branch.txt
+++ b/Documentation/git-filter-branch.txt
@@ -167,14 +167,12 @@
 	project root. Implies <<Remap_to_ancestor>>.
 
 --prune-empty::
-	Some kind of filters will generate empty commits, that left the tree
-	untouched.  This switch allow git-filter-branch to ignore such
-	commits.  Though, this switch only applies for commits that have one
-	and only one parent, it will hence keep merges points. Also, this
-	option is not compatible with the use of `--commit-filter`. Though you
-	just need to use the function 'git_commit_non_empty_tree "$@"' instead
-	of the `git commit-tree "$@"` idiom in your commit filter to make that
-	happen.
+	Some filters will generate empty commits that leave the tree untouched.
+	This option instructs git-filter-branch to remove such commits if they
+	have exactly one or zero non-pruned parents; merge commits will
+	therefore remain intact.  This option cannot be used together with
+	`--commit-filter`, though the same effect can be achieved by using the
+	provided `git_commit_non_empty_tree` function in a commit filter.
 
 --original <namespace>::
 	Use this option to set the namespace where the original commits
diff --git a/Documentation/git-for-each-ref.txt b/Documentation/git-for-each-ref.txt
index abe13f3..111e1be 100644
--- a/Documentation/git-for-each-ref.txt
+++ b/Documentation/git-for-each-ref.txt
@@ -95,11 +95,20 @@
 	The name of the ref (the part after $GIT_DIR/).
 	For a non-ambiguous short name of the ref append `:short`.
 	The option core.warnAmbiguousRefs is used to select the strict
-	abbreviation mode. If `strip=<N>` is appended, strips `<N>`
-	slash-separated path components from the front of the refname
-	(e.g., `%(refname:strip=2)` turns `refs/tags/foo` into `foo`.
-	`<N>` must be a positive integer.  If a displayed ref has fewer
-	components than `<N>`, the command aborts with an error.
+	abbreviation mode. If `lstrip=<N>` (`rstrip=<N>`) is appended, strips `<N>`
+	slash-separated path components from the front (back) of the refname
+	(e.g. `%(refname:lstrip=2)` turns `refs/tags/foo` into `foo` and
+	`%(refname:rstrip=2)` turns `refs/tags/foo` into `refs`).
+	If `<N>` is a negative number, strip as many path components as
+	necessary from the specified end to leave `-<N>` path components
+	(e.g. `%(refname:lstrip=-2)` turns
+	`refs/tags/foo` into `tags/foo` and `%(refname:rstrip=-1)`
+	turns `refs/tags/foo` into `refs`). When the ref does not have
+	enough components, the result becomes an empty string if
+	stripping with positive <N>, or it becomes the full refname if
+	stripping with negative <N>.  Neither is an error.
++
+`strip` can be used as a synomym to `lstrip`.
 
 objecttype::
 	The type of the object (`blob`, `tree`, `commit`, `tag`).
@@ -110,21 +119,31 @@
 objectname::
 	The object name (aka SHA-1).
 	For a non-ambiguous abbreviation of the object name append `:short`.
+	For an abbreviation of the object name with desired length append
+	`:short=<length>`, where the minimum length is MINIMUM_ABBREV. The
+	length may be exceeded to ensure unique object names.
 
 upstream::
 	The name of a local ref which can be considered ``upstream''
-	from the displayed ref. Respects `:short` in the same way as
-	`refname` above.  Additionally respects `:track` to show
-	"[ahead N, behind M]" and `:trackshort` to show the terse
-	version: ">" (ahead), "<" (behind), "<>" (ahead and behind),
-	or "=" (in sync).  Has no effect if the ref does not have
-	tracking information associated with it.
+	from the displayed ref. Respects `:short`, `:lstrip` and
+	`:rstrip` in the same way as `refname` above.  Additionally
+	respects `:track` to show "[ahead N, behind M]" and
+	`:trackshort` to show the terse version: ">" (ahead), "<"
+	(behind), "<>" (ahead and behind), or "=" (in sync). `:track`
+	also prints "[gone]" whenever unknown upstream ref is
+	encountered. Append `:track,nobracket` to show tracking
+	information without brackets (i.e "ahead N, behind M").  Has
+	no effect if the ref does not have tracking information
+	associated with it.  All the options apart from `nobracket`
+	are mutually exclusive, but if used together the last option
+	is selected.
 
 push::
-	The name of a local ref which represents the `@{push}` location
-	for the displayed ref. Respects `:short`, `:track`, and
-	`:trackshort` options as `upstream` does. Produces an empty
-	string if no `@{push}` ref is configured.
+	The name of a local ref which represents the `@{push}`
+	location for the displayed ref. Respects `:short`, `:lstrip`,
+	`:rstrip`, `:track`, and `:trackshort` options as `upstream`
+	does. Produces an empty string if no `@{push}` ref is
+	configured.
 
 HEAD::
 	'*' if HEAD matches current ref (the checked out branch), ' '
@@ -149,6 +168,25 @@
 	quoted, but if nested then only the topmost level performs
 	quoting.
 
+if::
+	Used as %(if)...%(then)...%(end) or
+	%(if)...%(then)...%(else)...%(end).  If there is an atom with
+	value or string literal after the %(if) then everything after
+	the %(then) is printed, else if the %(else) atom is used, then
+	everything after %(else) is printed. We ignore space when
+	evaluating the string before %(then), this is useful when we
+	use the %(HEAD) atom which prints either "*" or " " and we
+	want to apply the 'if' condition only on the 'HEAD' ref.
+	Append ":equals=<string>" or ":notequals=<string>" to compare
+	the value between the %(if:...) and %(then) atoms with the
+	given string.
+
+symref::
+	The ref which the given symbolic ref refers to. If not a
+	symbolic ref, nothing is printed. Respects the `:short`,
+	`:lstrip` and `:rstrip` options in the same way as `refname`
+	above.
+
 In addition to the above, for commit and tag objects, the header
 field names (`tree`, `parent`, `object`, `type`, and `tag`) can
 be used to specify the value in the header field.
@@ -186,6 +224,14 @@
 the date by adding `:` followed by date format name (see the
 values the `--date` option to linkgit:git-rev-list[1] takes).
 
+Some atoms like %(align) and %(if) always require a matching %(end).
+We call them "opening atoms" and sometimes denote them as %($open).
+
+When a scripting language specific quoting is in effect, everything
+between a top-level opening atom and its matching %(end) is evaluated
+according to the semantics of the opening atom and only its result
+from the top-level is quoted.
+
 
 EXAMPLES
 --------
@@ -273,6 +319,22 @@
 eval "$eval"
 ------------
 
+
+An example to show the usage of %(if)...%(then)...%(else)...%(end).
+This prefixes the current branch with a star.
+
+------------
+git for-each-ref --format="%(if)%(HEAD)%(then)* %(else)  %(end)%(refname:short)" refs/heads/
+------------
+
+
+An example to show the usage of %(if)...%(then)...%(end).
+This prints the authorname, if present.
+
+------------
+git for-each-ref --format="%(refname)%(if)%(authorname)%(then) Authored by: %(authorname)%(end)"
+------------
+
 SEE ALSO
 --------
 linkgit:git-show-ref[1]
diff --git a/Documentation/git-ls-files.txt b/Documentation/git-ls-files.txt
index 446209e..1cab703 100644
--- a/Documentation/git-ls-files.txt
+++ b/Documentation/git-ls-files.txt
@@ -77,7 +77,8 @@
 	succeed.
 
 -z::
-	\0 line termination on output.
+	\0 line termination on output and do not quote filenames.
+	See OUTPUT below for more information.
 
 -x <pattern>::
 --exclude=<pattern>::
@@ -196,9 +197,10 @@
 the user (or the porcelain) to see what should eventually be recorded at the
 path. (see linkgit:git-read-tree[1] for more information on state)
 
-When `-z` option is not used, TAB, LF, and backslash characters
-in pathnames are represented as `\t`, `\n`, and `\\`,
-respectively.
+Without the `-z` option, pathnames with "unusual" characters are
+quoted as explained for the configuration variable `core.quotePath`
+(see linkgit:git-config[1]).  Using `-z` the filename is output
+verbatim and the line is terminated by a NUL byte.
 
 
 Exclude Patterns
diff --git a/Documentation/git-ls-tree.txt b/Documentation/git-ls-tree.txt
index dbc91f9..9dee7be 100644
--- a/Documentation/git-ls-tree.txt
+++ b/Documentation/git-ls-tree.txt
@@ -53,7 +53,8 @@
 	Show object size of blob (file) entries.
 
 -z::
-	\0 line termination on output.
+	\0 line termination on output and do not quote filenames.
+	See OUTPUT FORMAT below for more information.
 
 --name-only::
 --name-status::
@@ -82,8 +83,6 @@
 -------------
         <mode> SP <type> SP <object> TAB <file>
 
-Unless the `-z` option is used, TAB, LF, and backslash characters
-in pathnames are represented as `\t`, `\n`, and `\\`, respectively.
 This output format is compatible with what `--index-info --stdin` of
 'git update-index' expects.
 
@@ -95,6 +94,11 @@
 with minimum width of 7 characters.  Object size is given only for blobs
 (file) entries; for other entries `-` character is used in place of size.
 
+Without the `-z` option, pathnames with "unusual" characters are
+quoted as explained for the configuration variable `core.quotePath`
+(see linkgit:git-config[1]).  Using `-z` the filename is output
+verbatim and the line is terminated by a NUL byte.
+
 GIT
 ---
 Part of the linkgit:git[1] suite
diff --git a/Documentation/git-name-rev.txt b/Documentation/git-name-rev.txt
index ca28fb8..e8e68f5 100644
--- a/Documentation/git-name-rev.txt
+++ b/Documentation/git-name-rev.txt
@@ -26,7 +26,18 @@
 
 --refs=<pattern>::
 	Only use refs whose names match a given shell pattern.  The pattern
-	can be one of branch name, tag name or fully qualified ref name.
+	can be one of branch name, tag name or fully qualified ref name. If
+	given multiple times, use refs whose names match any of the given shell
+	patterns. Use `--no-refs` to clear any previous ref patterns given.
+
+--exclude=<pattern>::
+	Do not use any ref whose name matches a given shell pattern. The
+	pattern can be one of branch name, tag name or fully qualified ref
+	name. If given multiple times, a ref will be excluded when it matches
+	any of the given patterns. When used together with --refs, a ref will
+	be used as a match only when it matches at least one --refs pattern and
+	does not match any --exclude patterns. Use `--no-exclude` to clear the
+	list of exclude patterns.
 
 --all::
 	List all commits reachable from all refs
diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt
index 7241e96..c40c470 100644
--- a/Documentation/git-rev-parse.txt
+++ b/Documentation/git-rev-parse.txt
@@ -217,6 +217,10 @@
 is not detected to lie in a Git repository or work tree
 print a message to stderr and exit with nonzero status.
 
+--absolute-git-dir::
+	Like `--git-dir`, but its output is always the canonicalized
+	absolute path.
+
 --git-common-dir::
 	Show `$GIT_COMMON_DIR` if defined, else `$GIT_DIR`.
 
@@ -257,6 +261,12 @@
 --show-toplevel::
 	Show the absolute path of the top-level directory.
 
+--show-superproject-working-tree
+	Show the absolute path of the root of the superproject's
+	working tree (if exists) that uses the current repository as
+	its submodule.  Outputs nothing if the current repository is
+	not used as a submodule by any project.
+
 --shared-index-path::
 	Show the path to the shared index file in split index mode, or
 	empty if not in split-index mode.
diff --git a/Documentation/git-stash.txt b/Documentation/git-stash.txt
index 2e9e344..70191d0 100644
--- a/Documentation/git-stash.txt
+++ b/Documentation/git-stash.txt
@@ -13,8 +13,11 @@
 'git stash' drop [-q|--quiet] [<stash>]
 'git stash' ( pop | apply ) [--index] [-q|--quiet] [<stash>]
 'git stash' branch <branchname> [<stash>]
-'git stash' [save [-p|--patch] [-k|--[no-]keep-index] [-q|--quiet]
-	     [-u|--include-untracked] [-a|--all] [<message>]]
+'git stash' save [-p|--patch] [-k|--[no-]keep-index] [-q|--quiet]
+	     [-u|--include-untracked] [-a|--all] [<message>]
+'git stash' [push [-p|--patch] [-k|--[no-]keep-index] [-q|--quiet]
+	     [-u|--include-untracked] [-a|--all] [-m|--message <message>]]
+	     [--] [<pathspec>...]]
 'git stash' clear
 'git stash' create [<message>]
 'git stash' store [-m|--message <message>] [-q|--quiet] <commit>
@@ -46,14 +49,24 @@
 -------
 
 save [-p|--patch] [-k|--[no-]keep-index] [-u|--include-untracked] [-a|--all] [-q|--quiet] [<message>]::
+push [-p|--patch] [-k|--[no-]keep-index] [-u|--include-untracked] [-a|--all] [-q|--quiet] [-m|--message <message>] [--] [<pathspec>...]::
 
 	Save your local modifications to a new 'stash' and roll them
 	back to HEAD (in the working tree and in the index).
 	The <message> part is optional and gives
-	the description along with the stashed state.  For quickly making
-	a snapshot, you can omit _both_ "save" and <message>, but giving
-	only <message> does not trigger this action to prevent a misspelled
-	subcommand from making an unwanted stash.
+	the description along with the stashed state.
++
+For quickly making a snapshot, you can omit "push".  In this mode,
+non-option arguments are not allowed to prevent a misspelled
+subcommand from making an unwanted stash.  The two exceptions to this
+are `stash -p` which acts as alias for `stash push -p` and pathspecs,
+which are allowed after a double hyphen `--` for disambiguation.
++
+When pathspec is given to 'git stash push', the new stash records the
+modified states only for the files that match the pathspec.  The index
+entries and working tree files are then rolled back to the state in
+HEAD only for these files, too, leaving files that do not match the
+pathspec intact.
 +
 If the `--keep-index` option is used, all changes already added to the
 index are left intact.
diff --git a/Documentation/git-status.txt b/Documentation/git-status.txt
index 725065e..ba87365 100644
--- a/Documentation/git-status.txt
+++ b/Documentation/git-status.txt
@@ -322,10 +322,9 @@
 without any quoting and lines are terminated with a NUL (ASCII 0x00)
 byte.
 
-Otherwise, all pathnames will be "C-quoted" if they contain any tab,
-linefeed, double quote, or backslash characters. In C-quoting, these
-characters will be replaced with the corresponding C-style escape
-sequences and the resulting pathname will be double quoted.
+Without the `-z` option, pathnames with "unusual" characters are
+quoted as explained for the configuration variable `core.quotePath`
+(see linkgit:git-config[1]).
 
 
 CONFIGURATION
diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 8acc72e..e05d0cd 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -73,13 +73,17 @@
 +
 <repository> is the URL of the new submodule's origin repository.
 This may be either an absolute URL, or (if it begins with ./
-or ../), the location relative to the superproject's origin
+or ../), the location relative to the superproject's default remote
 repository (Please note that to specify a repository 'foo.git'
 which is located right next to a superproject 'bar.git', you'll
 have to use '../foo.git' instead of './foo.git' - as one might expect
 when following the rules for relative URLs - because the evaluation
 of relative URLs in Git is identical to that of relative directories).
-If the superproject doesn't have an origin configured
++
+The default remote is the remote of the remote tracking branch
+of the current branch. If no such remote tracking branch exists or
+the HEAD is detached, "origin" is assumed to be the default remote.
+If the superproject doesn't have a default remote configured
 the superproject is its own authoritative upstream and the current
 working directory is used instead.
 +
@@ -118,18 +122,24 @@
 
 init [--] [<path>...]::
 	Initialize the submodules recorded in the index (which were
-	added and committed elsewhere) by copying submodule
-	names and urls from .gitmodules to .git/config.
-	Optional <path> arguments limit which submodules will be initialized.
-	It will also copy the value of `submodule.$name.update` into
-	.git/config.
-	The key used in .git/config is `submodule.$name.url`.
-	This command does not alter existing information in .git/config.
-	You can then customize the submodule clone URLs in .git/config
-	for your local setup and proceed to `git submodule update`;
-	you can also just use `git submodule update --init` without
-	the explicit 'init' step if you do not intend to customize
-	any submodule locations.
+	added and committed elsewhere) by setting `submodule.$name.url`
+	in .git/config. It uses the same setting from .gitmodules as
+	a template. If the URL is relative, it will be resolved using
+	the default remote. If there is no default remote, the current
+	repository will be assumed to be upstream.
++
+Optional <path> arguments limit which submodules will be initialized.
+If no path is specified, all submodules are initialized.
++
+When present, it will also copy the value of `submodule.$name.update`.
+This command does not alter existing information in .git/config.
+You can then customize the submodule clone URLs in .git/config
+for your local setup and proceed to `git submodule update`;
+you can also just use `git submodule update --init` without
+the explicit 'init' step if you do not intend to customize
+any submodule locations.
++
+See the add subcommand for the defintion of default remote.
 
 deinit [-f|--force] (--all|[--] <path>...)::
 	Unregister the given submodules, i.e. remove the whole
diff --git a/Documentation/git-update-index.txt b/Documentation/git-update-index.txt
index 7386c93..1579abf 100644
--- a/Documentation/git-update-index.txt
+++ b/Documentation/git-update-index.txt
@@ -163,14 +163,16 @@
 
 --split-index::
 --no-split-index::
-	Enable or disable split index mode. If enabled, the index is
-	split into two files, $GIT_DIR/index and $GIT_DIR/sharedindex.<SHA-1>.
-	Changes are accumulated in $GIT_DIR/index while the shared
-	index file contains all index entries stays unchanged. If
-	split-index mode is already enabled and `--split-index` is
-	given again, all changes in $GIT_DIR/index are pushed back to
-	the shared index file. This mode is designed for very large
-	indexes that take a significant amount of time to read or write.
+	Enable or disable split index mode. If split-index mode is
+	already enabled and `--split-index` is given again, all
+	changes in $GIT_DIR/index are pushed back to the shared index
+	file.
++
+These options take effect whatever the value of the `core.splitIndex`
+configuration variable (see linkgit:git-config[1]). But a warning is
+emitted when the change goes against the configured value, as the
+configured value will take effect next time the index is read and this
+will remove the intended effect of the option.
 
 --untracked-cache::
 --no-untracked-cache::
@@ -388,6 +390,31 @@
 different from assume-unchanged bit's. Skip-worktree also takes
 precedence over assume-unchanged bit when both are set.
 
+Split index
+-----------
+
+This mode is designed for repositories with very large indexes, and
+aims at reducing the time it takes to repeatedly write these indexes.
+
+In this mode, the index is split into two files, $GIT_DIR/index and
+$GIT_DIR/sharedindex.<SHA-1>. Changes are accumulated in
+$GIT_DIR/index, the split index, while the shared index file contains
+all index entries and stays unchanged.
+
+All changes in the split index are pushed back to the shared index
+file when the number of entries in the split index reaches a level
+specified by the splitIndex.maxPercentChange config variable (see
+linkgit:git-config[1]).
+
+Each time a new shared index file is created, the old shared index
+files are deleted if their modification time is older than what is
+specified by the splitIndex.sharedIndexExpire config variable (see
+linkgit:git-config[1]).
+
+To avoid deleting a shared index file that is still used, its
+modification time is updated to the current time everytime a new split
+index based on the shared index file is either created or read from.
+
 Untracked cache
 ---------------
 
diff --git a/Documentation/git.txt b/Documentation/git.txt
index aa895da..df0941d 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -1025,6 +1025,12 @@
 personal `.ssh/config` file.  Please consult your ssh documentation
 for further details.
 
+`GIT_SSH_VARIANT`::
+	If this environment variable is set, it overrides Git's autodetection
+	whether `GIT_SSH`/`GIT_SSH_COMMAND`/`core.sshCommand` refer to OpenSSH,
+	plink or tortoiseplink. This variable overrides the config setting
+	`ssh.variant` that serves the same purpose.
+
 `GIT_ASKPASS`::
 	If this environment variable is set, then Git commands which need to
 	acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt
index e0b66c1..a53d093 100644
--- a/Documentation/gitattributes.txt
+++ b/Documentation/gitattributes.txt
@@ -21,9 +21,11 @@
 	pattern	attr1 attr2 ...
 
 That is, a pattern followed by an attributes list,
-separated by whitespaces.  When the pattern matches the
-path in question, the attributes listed on the line are given to
-the path.
+separated by whitespaces. Leading and trailing whitespaces are
+ignored. Lines that begin with '#' are ignored. Patterns
+that begin with a double quote are quoted in C style.
+When the pattern matches the path in question, the attributes
+listed on the line are given to the path.
 
 Each attribute can be in one of these states for a given path:
 
@@ -86,7 +88,7 @@
 Attributes for all users on a system should be placed in the
 `$(prefix)/etc/gitattributes` file.
 
-Sometimes you would need to override an setting of an attribute
+Sometimes you would need to override a setting of an attribute
 for a path to `Unspecified` state.  This can be done by listing
 the name of the attribute prefixed with an exclamation point `!`.
 
diff --git a/Documentation/gitdiffcore.txt b/Documentation/gitdiffcore.txt
index 46bc6d0..c0a60f3 100644
--- a/Documentation/gitdiffcore.txt
+++ b/Documentation/gitdiffcore.txt
@@ -84,8 +84,8 @@
 diff-patch format.
 
 
-diffcore-break: For Splitting Up "Complete Rewrites"
-----------------------------------------------------
+diffcore-break: For Splitting Up Complete Rewrites
+--------------------------------------------------
 
 The second transformation in the chain is diffcore-break, and is
 controlled by the -B option to the 'git diff-{asterisk}' commands.  This is
@@ -119,7 +119,7 @@
 after "-B" option (e.g. "-B75" to tell it to use 75%).
 
 
-diffcore-rename: For Detection Renames and Copies
+diffcore-rename: For Detecting Renames and Copies
 -------------------------------------------------
 
 This transformation is used to detect renames and copies, and is
@@ -177,8 +177,8 @@
 copied happened to have been modified in the same changeset.
 
 
-diffcore-merge-broken: For Putting "Complete Rewrites" Back Together
---------------------------------------------------------------------
+diffcore-merge-broken: For Putting Complete Rewrites Back Together
+------------------------------------------------------------------
 
 This transformation is used to merge filepairs broken by
 diffcore-break, and not transformed into rename/copy by
diff --git a/Documentation/glossary-content.txt b/Documentation/glossary-content.txt
index 8ad29e6..6e991c2 100644
--- a/Documentation/glossary-content.txt
+++ b/Documentation/glossary-content.txt
@@ -384,10 +384,33 @@
 +
 Glob magic is incompatible with literal magic.
 
+attr;;
+After `attr:` comes a space separated list of "attribute
+requirements", all of which must be met in order for the
+path to be considered a match; this is in addition to the
+usual non-magic pathspec pattern matching.
+See linkgit:gitattributes[5].
++
+Each of the attribute requirements for the path takes one of
+these forms:
+
+- "`ATTR`" requires that the attribute `ATTR` be set.
+
+- "`-ATTR`" requires that the attribute `ATTR` be unset.
+
+- "`ATTR=VALUE`" requires that the attribute `ATTR` be
+  set to the string `VALUE`.
+
+- "`!ATTR`" requires that the attribute `ATTR` be
+  unspecified.
++
+
 exclude;;
 	After a path matches any non-exclude pathspec, it will be run
-	through all exclude pathspec (magic signature: `!`). If it
-	matches, the path is ignored.
+	through all exclude pathspec (magic signature: `!` or its
+	synonym `^`). If it matches, the path is ignored.  When there
+	is no non-exclude pathspec, the exclusion is applied to the
+	result set as if invoked without any pathspec.
 --
 
 [[def_parent]]parent::
diff --git a/Documentation/technical/api-gitattributes.txt b/Documentation/technical/api-gitattributes.txt
index 2602668..e7cbb7c 100644
--- a/Documentation/technical/api-gitattributes.txt
+++ b/Documentation/technical/api-gitattributes.txt
@@ -16,10 +16,15 @@
 	of no interest to the calling programs.  The name of the
 	attribute can be retrieved by calling `git_attr_name()`.
 
-`struct git_attr_check`::
+`struct attr_check_item`::
 
-	This structure represents a set of attributes to check in a call
-	to `git_check_attr()` function, and receives the results.
+	This structure represents one attribute and its value.
+
+`struct attr_check`::
+
+	This structure represents a collection of `attr_check_item`.
+	It is passed to `git_check_attr()` function, specifying the
+	attributes to check, and receives their values.
 
 
 Attribute Values
@@ -27,7 +32,7 @@
 
 An attribute for a path can be in one of four states: Set, Unset,
 Unspecified or set to a string, and `.value` member of `struct
-git_attr_check` records it.  There are three macros to check these:
+attr_check_item` records it.  There are three macros to check these:
 
 `ATTR_TRUE()`::
 
@@ -48,49 +53,51 @@
 Querying Specific Attributes
 ----------------------------
 
-* Prepare an array of `struct git_attr_check` to define the list of
-  attributes you would want to check.  To populate this array, you would
-  need to define necessary attributes by calling `git_attr()` function.
+* Prepare `struct attr_check` using attr_check_initl()
+  function, enumerating the names of attributes whose values you are
+  interested in, terminated with a NULL pointer.  Alternatively, an
+  empty `struct attr_check` can be prepared by calling
+  `attr_check_alloc()` function and then attributes you want to
+  ask about can be added to it with `attr_check_append()`
+  function.
 
 * Call `git_check_attr()` to check the attributes for the path.
 
-* Inspect `git_attr_check` structure to see how each of the attribute in
-  the array is defined for the path.
+* Inspect `attr_check` structure to see how each of the
+  attribute in the array is defined for the path.
 
 
 Example
 -------
 
-To see how attributes "crlf" and "indent" are set for different paths.
+To see how attributes "crlf" and "ident" are set for different paths.
 
-. Prepare an array of `struct git_attr_check` with two elements (because
-  we are checking two attributes).  Initialize their `attr` member with
-  pointers to `struct git_attr` obtained by calling `git_attr()`:
+. Prepare a `struct attr_check` with two elements (because
+  we are checking two attributes):
 
 ------------
-static struct git_attr_check check[2];
+static struct attr_check *check;
 static void setup_check(void)
 {
-	if (check[0].attr)
+	if (check)
 		return; /* already done */
-	check[0].attr = git_attr("crlf");
-	check[1].attr = git_attr("ident");
+	check = attr_check_initl("crlf", "ident", NULL);
 }
 ------------
 
-. Call `git_check_attr()` with the prepared array of `struct git_attr_check`:
+. Call `git_check_attr()` with the prepared `struct attr_check`:
 
 ------------
 	const char *path;
 
 	setup_check();
-	git_check_attr(path, ARRAY_SIZE(check), check);
+	git_check_attr(path, check);
 ------------
 
-. Act on `.value` member of the result, left in `check[]`:
+. Act on `.value` member of the result, left in `check->items[]`:
 
 ------------
-	const char *value = check[0].value;
+	const char *value = check->items[0].value;
 
 	if (ATTR_TRUE(value)) {
 		The attribute is Set, by listing only the name of the
@@ -109,20 +116,39 @@
 	}
 ------------
 
+To see how attributes in argv[] are set for different paths, only
+the first step in the above would be different.
+
+------------
+static struct attr_check *check;
+static void setup_check(const char **argv)
+{
+	check = attr_check_alloc();
+	while (*argv) {
+		struct git_attr *attr = git_attr(*argv);
+		attr_check_append(check, attr);
+		argv++;
+	}
+}
+------------
+
 
 Querying All Attributes
 -----------------------
 
 To get the values of all attributes associated with a file:
 
-* Call `git_all_attrs()`, which returns an array of `git_attr_check`
-  structures.
+* Prepare an empty `attr_check` structure by calling
+  `attr_check_alloc()`.
 
-* Iterate over the `git_attr_check` array to examine the attribute
-  names and values.  The name of the attribute described by a
-  `git_attr_check` object can be retrieved via
-  `git_attr_name(check[i].attr)`.  (Please note that no items will be
-  returned for unset attributes, so `ATTR_UNSET()` will return false
-  for all returned `git_array_check` objects.)
+* Call `git_all_attrs()`, which populates the `attr_check`
+  with the attributes attached to the path.
 
-* Free the `git_array_check` array.
+* Iterate over the `attr_check.items[]` array to examine
+  the attribute names and values.  The name of the attribute
+  described by a  `attr_check.items[]` object can be retrieved via
+  `git_attr_name(check->items[i].attr)`.  (Please note that no items
+  will be returned for unset attributes, so `ATTR_UNSET()` will return
+  false for all returned `attr_check.items[]` objects.)
+
+* Free the `attr_check` struct by calling `attr_check_free()`.
diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt
index 27bd701..36768b4 100644
--- a/Documentation/technical/api-parse-options.txt
+++ b/Documentation/technical/api-parse-options.txt
@@ -168,6 +168,11 @@
 	Introduce an option with string argument.
 	The string argument is put into `str_var`.
 
+`OPT_STRING_LIST(short, long, &struct string_list, arg_str, description)`::
+	Introduce an option with string argument.
+	The string argument is stored as an element in `string_list`.
+	Use of `--no-option` will clear the list of preceding values.
+
 `OPT_INTEGER(short, long, &int_var, description)`::
 	Introduce an option with integer argument.
 	The integer is put into `int_var`.
diff --git a/GIT-VERSION-GEN b/GIT-VERSION-GEN
index 6a208e9..817d1cf 100755
--- a/GIT-VERSION-GEN
+++ b/GIT-VERSION-GEN
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 GVF=GIT-VERSION-FILE
-DEF_VER=v2.12.0
+DEF_VER=v2.12.GIT
 
 LF='
 '
diff --git a/Makefile b/Makefile
index 8e4081e..a5a11e7 100644
--- a/Makefile
+++ b/Makefile
@@ -102,8 +102,6 @@
 #
 # Define MKDIR_WO_TRAILING_SLASH if your mkdir() can't deal with trailing slash.
 #
-# Define NO_MKSTEMPS if you don't have mkstemps in the C library.
-#
 # Define NO_GECOS_IN_PWENT if you don't have pw_gecos in struct passwd
 # in the C library.
 #
@@ -781,6 +779,7 @@
 LIB_OBJS += notes-merge.o
 LIB_OBJS += notes-utils.o
 LIB_OBJS += object.o
+LIB_OBJS += oidset.o
 LIB_OBJS += pack-bitmap.o
 LIB_OBJS += pack-bitmap-write.o
 LIB_OBJS += pack-check.o
@@ -932,6 +931,7 @@
 BUILTIN_OBJS += builtin/pull.o
 BUILTIN_OBJS += builtin/push.o
 BUILTIN_OBJS += builtin/read-tree.o
+BUILTIN_OBJS += builtin/rebase--helper.o
 BUILTIN_OBJS += builtin/receive-pack.o
 BUILTIN_OBJS += builtin/reflog.o
 BUILTIN_OBJS += builtin/remote.o
@@ -1280,9 +1280,6 @@
 	COMPAT_CFLAGS += -DMKDIR_WO_TRAILING_SLASH
 	COMPAT_OBJS += compat/mkdir.o
 endif
-ifdef NO_MKSTEMPS
-	COMPAT_CFLAGS += -DNO_MKSTEMPS
-endif
 ifdef NO_UNSETENV
 	COMPAT_CFLAGS += -DNO_UNSETENV
 	COMPAT_OBJS += compat/unsetenv.o
@@ -1387,19 +1384,19 @@
 endif
 
 ifdef BLK_SHA1
-	SHA1_HEADER = "block-sha1/sha1.h"
 	LIB_OBJS += block-sha1/sha1.o
+	BASIC_CFLAGS += -DSHA1_BLK
 else
 ifdef PPC_SHA1
-	SHA1_HEADER = "ppc/sha1.h"
 	LIB_OBJS += ppc/sha1.o ppc/sha1ppc.o
+	BASIC_CFLAGS += -DSHA1_PPC
 else
 ifdef APPLE_COMMON_CRYPTO
 	COMPAT_CFLAGS += -DCOMMON_DIGEST_FOR_OPENSSL
-	SHA1_HEADER = <CommonCrypto/CommonDigest.h>
+	BASIC_CFLAGS += -DSHA1_APPLE
 else
-	SHA1_HEADER = <openssl/sha.h>
 	EXTLIBS += $(LIB_4_CRYPTO)
+	BASIC_CFLAGS += -DSHA1_OPENSSL
 endif
 endif
 endif
@@ -1591,7 +1588,6 @@
 
 # Shell quote (do not use $(call) to accommodate ancient setups);
 
-SHA1_HEADER_SQ = $(subst ','\'',$(SHA1_HEADER))
 ETC_GITCONFIG_SQ = $(subst ','\'',$(ETC_GITCONFIG))
 ETC_GITATTRIBUTES_SQ = $(subst ','\'',$(ETC_GITATTRIBUTES))
 
@@ -1624,8 +1620,7 @@
 # from the dependency list, that would make each entry appear twice.
 LIBS = $(filter-out %.o, $(GITLIBS)) $(EXTLIBS)
 
-BASIC_CFLAGS += -DSHA1_HEADER='$(SHA1_HEADER_SQ)' \
-	$(COMPAT_CFLAGS)
+BASIC_CFLAGS += $(COMPAT_CFLAGS)
 LIB_OBJS += $(COMPAT_OBJS)
 
 # Quote for C
@@ -2254,6 +2249,9 @@
 ifdef GIT_PERF_MAKE_OPTS
 	@echo GIT_PERF_MAKE_OPTS=\''$(subst ','\'',$(subst ','\'',$(GIT_PERF_MAKE_OPTS)))'\' >>$@+
 endif
+ifdef GIT_INTEROP_MAKE_OPTS
+	@echo GIT_INTEROP_MAKE_OPTS=\''$(subst ','\'',$(subst ','\'',$(GIT_INTEROP_MAKE_OPTS)))'\' >>$@+
+endif
 ifdef TEST_GIT_INDEX_VERSION
 	@echo TEST_GIT_INDEX_VERSION=\''$(subst ','\'',$(subst ','\'',$(TEST_GIT_INDEX_VERSION)))'\' >>$@+
 endif
diff --git a/README.md b/README.md
index c0cd558..f17af66 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@
 
 Please read the file [INSTALL][] for installation instructions.
 
-Many Git online resources are accessible from http://git-scm.com/
+Many Git online resources are accessible from <https://git-scm.com/>
 including full documentation and Git related tools.
 
 See [Documentation/gittutorial.txt][] to get started, then see
@@ -33,8 +33,8 @@
 [Documentation/SubmittingPatches][] for instructions on patch submission).
 To subscribe to the list, send an email with just "subscribe git" in
 the body to majordomo@vger.kernel.org. The mailing list archives are
-available at https://public-inbox.org/git,
-http://marc.info/?l=git and other archival sites.
+available at <https://public-inbox.org/git/>,
+<http://marc.info/?l=git> and other archival sites.
 
 The maintainer frequently sends the "What's cooking" reports that
 list the current status of various development topics to the mailing
diff --git a/RelNotes b/RelNotes
index d09c3d5..125bf78 120000
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes/2.12.0.txt
\ No newline at end of file
+Documentation/RelNotes/2.13.0.txt
\ No newline at end of file
diff --git a/abspath.c b/abspath.c
index 2f0c26e..b02e068 100644
--- a/abspath.c
+++ b/abspath.c
@@ -214,12 +214,12 @@
 	return strbuf_realpath(&realpath, path, 0);
 }
 
-char *real_pathdup(const char *path)
+char *real_pathdup(const char *path, int die_on_error)
 {
 	struct strbuf realpath = STRBUF_INIT;
 	char *retval = NULL;
 
-	if (strbuf_realpath(&realpath, path, 0))
+	if (strbuf_realpath(&realpath, path, die_on_error))
 		retval = strbuf_detach(&realpath, NULL);
 
 	strbuf_release(&realpath);
diff --git a/archive.c b/archive.c
index 01751e5..60b8891 100644
--- a/archive.c
+++ b/archive.c
@@ -87,19 +87,6 @@
 	return buffer;
 }
 
-static void setup_archive_check(struct git_attr_check *check)
-{
-	static struct git_attr *attr_export_ignore;
-	static struct git_attr *attr_export_subst;
-
-	if (!attr_export_ignore) {
-		attr_export_ignore = git_attr("export-ignore");
-		attr_export_subst = git_attr("export-subst");
-	}
-	check[0].attr = attr_export_ignore;
-	check[1].attr = attr_export_subst;
-}
-
 struct directory {
 	struct directory *up;
 	struct object_id oid;
@@ -120,10 +107,10 @@
 		void *context)
 {
 	static struct strbuf path = STRBUF_INIT;
+	static struct attr_check *check;
 	struct archiver_context *c = context;
 	struct archiver_args *args = c->args;
 	write_archive_entry_fn_t write_entry = c->write_entry;
-	struct git_attr_check check[2];
 	const char *path_without_prefix;
 	int err;
 
@@ -137,11 +124,12 @@
 		strbuf_addch(&path, '/');
 	path_without_prefix = path.buf + args->baselen;
 
-	setup_archive_check(check);
-	if (!git_check_attr(path_without_prefix, ARRAY_SIZE(check), check)) {
-		if (ATTR_TRUE(check[0].value))
+	if (!check)
+		check = attr_check_initl("export-ignore", "export-subst", NULL);
+	if (!git_check_attr(path_without_prefix, check)) {
+		if (ATTR_TRUE(check->items[0].value))
 			return 0;
-		args->convert = ATTR_TRUE(check[1].value);
+		args->convert = ATTR_TRUE(check->items[1].value);
 	}
 
 	if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
diff --git a/attr.c b/attr.c
index 1fcf042..7e21344 100644
--- a/attr.c
+++ b/attr.c
@@ -13,6 +13,8 @@
 #include "attr.h"
 #include "dir.h"
 #include "utf8.h"
+#include "quote.h"
+#include "thread-utils.h"
 
 const char git_attr__true[] = "(builtin)true";
 const char git_attr__false[] = "\0(builtin)false";
@@ -22,99 +24,234 @@
 #define ATTR__UNSET NULL
 #define ATTR__UNKNOWN git_attr__unknown
 
-/* This is a randomly chosen prime. */
-#define HASHSIZE 257
-
 #ifndef DEBUG_ATTR
 #define DEBUG_ATTR 0
 #endif
 
 struct git_attr {
-	struct git_attr *next;
-	unsigned h;
-	int attr_nr;
-	int maybe_macro;
-	int maybe_real;
-	char name[FLEX_ARRAY];
+	int attr_nr; /* unique attribute number */
+	char name[FLEX_ARRAY]; /* attribute name */
 };
-static int attr_nr;
-static int cannot_trust_maybe_real;
 
-static struct git_attr_check *check_all_attr;
-static struct git_attr *(git_attr_hash[HASHSIZE]);
-
-char *git_attr_name(struct git_attr *attr)
+const char *git_attr_name(const struct git_attr *attr)
 {
 	return attr->name;
 }
 
-static unsigned hash_name(const char *name, int namelen)
-{
-	unsigned val = 0, c;
+struct attr_hashmap {
+	struct hashmap map;
+#ifndef NO_PTHREADS
+	pthread_mutex_t mutex;
+#endif
+};
 
-	while (namelen--) {
-		c = *name++;
-		val = ((val << 7) | (val >> 22)) ^ c;
-	}
-	return val;
+static inline void hashmap_lock(struct attr_hashmap *map)
+{
+#ifndef NO_PTHREADS
+	pthread_mutex_lock(&map->mutex);
+#endif
 }
 
-static int invalid_attr_name(const char *name, int namelen)
+static inline void hashmap_unlock(struct attr_hashmap *map)
+{
+#ifndef NO_PTHREADS
+	pthread_mutex_unlock(&map->mutex);
+#endif
+}
+
+/*
+ * The global dictionary of all interned attributes.  This
+ * is a singleton object which is shared between threads.
+ * Access to this dictionary must be surrounded with a mutex.
+ */
+static struct attr_hashmap g_attr_hashmap;
+
+/* The container for objects stored in "struct attr_hashmap" */
+struct attr_hash_entry {
+	struct hashmap_entry ent; /* must be the first member! */
+	const char *key; /* the key; memory should be owned by value */
+	size_t keylen; /* length of the key */
+	void *value; /* the stored value */
+};
+
+/* attr_hashmap comparison function */
+static int attr_hash_entry_cmp(const struct attr_hash_entry *a,
+			       const struct attr_hash_entry *b,
+			       void *unused)
+{
+	return (a->keylen != b->keylen) || strncmp(a->key, b->key, a->keylen);
+}
+
+/* Initialize an 'attr_hashmap' object */
+static void attr_hashmap_init(struct attr_hashmap *map)
+{
+	hashmap_init(&map->map, (hashmap_cmp_fn) attr_hash_entry_cmp, 0);
+}
+
+/*
+ * Retrieve the 'value' stored in a hashmap given the provided 'key'.
+ * If there is no matching entry, return NULL.
+ */
+static void *attr_hashmap_get(struct attr_hashmap *map,
+			      const char *key, size_t keylen)
+{
+	struct attr_hash_entry k;
+	struct attr_hash_entry *e;
+
+	if (!map->map.tablesize)
+		attr_hashmap_init(map);
+
+	hashmap_entry_init(&k, memhash(key, keylen));
+	k.key = key;
+	k.keylen = keylen;
+	e = hashmap_get(&map->map, &k, NULL);
+
+	return e ? e->value : NULL;
+}
+
+/* Add 'value' to a hashmap based on the provided 'key'. */
+static void attr_hashmap_add(struct attr_hashmap *map,
+			     const char *key, size_t keylen,
+			     void *value)
+{
+	struct attr_hash_entry *e;
+
+	if (!map->map.tablesize)
+		attr_hashmap_init(map);
+
+	e = xmalloc(sizeof(struct attr_hash_entry));
+	hashmap_entry_init(e, memhash(key, keylen));
+	e->key = key;
+	e->keylen = keylen;
+	e->value = value;
+
+	hashmap_add(&map->map, e);
+}
+
+struct all_attrs_item {
+	const struct git_attr *attr;
+	const char *value;
+	/*
+	 * If 'macro' is non-NULL, indicates that 'attr' is a macro based on
+	 * the current attribute stack and contains a pointer to the match_attr
+	 * definition of the macro
+	 */
+	const struct match_attr *macro;
+};
+
+/*
+ * Reallocate and reinitialize the array of all attributes (which is used in
+ * the attribute collection process) in 'check' based on the global dictionary
+ * of attributes.
+ */
+static void all_attrs_init(struct attr_hashmap *map, struct attr_check *check)
+{
+	int i;
+
+	hashmap_lock(map);
+
+	if (map->map.size < check->all_attrs_nr)
+		die("BUG: interned attributes shouldn't be deleted");
+
+	/*
+	 * If the number of attributes in the global dictionary has increased
+	 * (or this attr_check instance doesn't have an initialized all_attrs
+	 * field), reallocate the provided attr_check instance's all_attrs
+	 * field and fill each entry with its corresponding git_attr.
+	 */
+	if (map->map.size != check->all_attrs_nr) {
+		struct attr_hash_entry *e;
+		struct hashmap_iter iter;
+		hashmap_iter_init(&map->map, &iter);
+
+		REALLOC_ARRAY(check->all_attrs, map->map.size);
+		check->all_attrs_nr = map->map.size;
+
+		while ((e = hashmap_iter_next(&iter))) {
+			const struct git_attr *a = e->value;
+			check->all_attrs[a->attr_nr].attr = a;
+		}
+	}
+
+	hashmap_unlock(map);
+
+	/*
+	 * Re-initialize every entry in check->all_attrs.
+	 * This re-initialization can live outside of the locked region since
+	 * the attribute dictionary is no longer being accessed.
+	 */
+	for (i = 0; i < check->all_attrs_nr; i++) {
+		check->all_attrs[i].value = ATTR__UNKNOWN;
+		check->all_attrs[i].macro = NULL;
+	}
+}
+
+static int attr_name_valid(const char *name, size_t namelen)
 {
 	/*
 	 * Attribute name cannot begin with '-' and must consist of
 	 * characters from [-A-Za-z0-9_.].
 	 */
 	if (namelen <= 0 || *name == '-')
-		return -1;
+		return 0;
 	while (namelen--) {
 		char ch = *name++;
 		if (! (ch == '-' || ch == '.' || ch == '_' ||
 		       ('0' <= ch && ch <= '9') ||
 		       ('a' <= ch && ch <= 'z') ||
 		       ('A' <= ch && ch <= 'Z')) )
-			return -1;
+			return 0;
 	}
-	return 0;
+	return 1;
 }
 
-static struct git_attr *git_attr_internal(const char *name, int len)
+static void report_invalid_attr(const char *name, size_t len,
+				const char *src, int lineno)
 {
-	unsigned hval = hash_name(name, len);
-	unsigned pos = hval % HASHSIZE;
+	struct strbuf err = STRBUF_INIT;
+	strbuf_addf(&err, _("%.*s is not a valid attribute name"),
+		    (int) len, name);
+	fprintf(stderr, "%s: %s:%d\n", err.buf, src, lineno);
+	strbuf_release(&err);
+}
+
+/*
+ * Given a 'name', lookup and return the corresponding attribute in the global
+ * dictionary.  If no entry is found, create a new attribute and store it in
+ * the dictionary.
+ */
+static const struct git_attr *git_attr_internal(const char *name, int namelen)
+{
 	struct git_attr *a;
 
-	for (a = git_attr_hash[pos]; a; a = a->next) {
-		if (a->h == hval &&
-		    !memcmp(a->name, name, len) && !a->name[len])
-			return a;
-	}
-
-	if (invalid_attr_name(name, len))
+	if (!attr_name_valid(name, namelen))
 		return NULL;
 
-	FLEX_ALLOC_MEM(a, name, name, len);
-	a->h = hval;
-	a->next = git_attr_hash[pos];
-	a->attr_nr = attr_nr++;
-	a->maybe_macro = 0;
-	a->maybe_real = 0;
-	git_attr_hash[pos] = a;
+	hashmap_lock(&g_attr_hashmap);
 
-	REALLOC_ARRAY(check_all_attr, attr_nr);
-	check_all_attr[a->attr_nr].attr = a;
-	check_all_attr[a->attr_nr].value = ATTR__UNKNOWN;
+	a = attr_hashmap_get(&g_attr_hashmap, name, namelen);
+
+	if (!a) {
+		FLEX_ALLOC_MEM(a, name, name, namelen);
+		a->attr_nr = g_attr_hashmap.map.size;
+
+		attr_hashmap_add(&g_attr_hashmap, a->name, namelen, a);
+		assert(a->attr_nr == (g_attr_hashmap.map.size - 1));
+	}
+
+	hashmap_unlock(&g_attr_hashmap);
+
 	return a;
 }
 
-struct git_attr *git_attr(const char *name)
+const struct git_attr *git_attr(const char *name)
 {
 	return git_attr_internal(name, strlen(name));
 }
 
 /* What does a matched pattern decide? */
 struct attr_state {
-	struct git_attr *attr;
+	const struct git_attr *attr;
 	const char *setto;
 };
 
@@ -131,9 +268,8 @@
  * If is_macro is true, then u.attr is a pointer to the git_attr being
  * defined.
  *
- * If is_macro is false, then u.pattern points at the filename pattern
- * to which the rule applies.  (The memory pointed to is part of the
- * memory block allocated for the match_attr instance.)
+ * If is_macro is false, then u.pat is the filename pattern to which the
+ * rule applies.
  *
  * In either case, num_attr is the number of attributes affected by
  * this rule, and state is an array listing them.  The attributes are
@@ -142,7 +278,7 @@
 struct match_attr {
 	union {
 		struct pattern pat;
-		struct git_attr *attr;
+		const struct git_attr *attr;
 	} u;
 	char is_macro;
 	unsigned num_attr;
@@ -177,13 +313,17 @@
 			cp++;
 			len--;
 		}
-		if (invalid_attr_name(cp, len)) {
-			fprintf(stderr,
-				"%.*s is not a valid attribute name: %s:%d\n",
-				len, cp, src, lineno);
+		if (!attr_name_valid(cp, len)) {
+			report_invalid_attr(cp, len, src, lineno);
 			return NULL;
 		}
 	} else {
+		/*
+		 * As this function is always called twice, once with
+		 * e == NULL in the first pass and then e != NULL in
+		 * the second pass, no need for attr_name_valid()
+		 * check here.
+		 */
 		if (*cp == '-' || *cp == '!') {
 			e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
 			cp++;
@@ -207,41 +347,47 @@
 	const char *cp, *name, *states;
 	struct match_attr *res = NULL;
 	int is_macro;
+	struct strbuf pattern = STRBUF_INIT;
 
 	cp = line + strspn(line, blank);
 	if (!*cp || *cp == '#')
 		return NULL;
 	name = cp;
-	namelen = strcspn(name, blank);
+
+	if (*cp == '"' && !unquote_c_style(&pattern, name, &states)) {
+		name = pattern.buf;
+		namelen = pattern.len;
+	} else {
+		namelen = strcspn(name, blank);
+		states = name + namelen;
+	}
+
 	if (strlen(ATTRIBUTE_MACRO_PREFIX) < namelen &&
 	    starts_with(name, ATTRIBUTE_MACRO_PREFIX)) {
 		if (!macro_ok) {
 			fprintf(stderr, "%s not allowed: %s:%d\n",
 				name, src, lineno);
-			return NULL;
+			goto fail_return;
 		}
 		is_macro = 1;
 		name += strlen(ATTRIBUTE_MACRO_PREFIX);
 		name += strspn(name, blank);
 		namelen = strcspn(name, blank);
-		if (invalid_attr_name(name, namelen)) {
-			fprintf(stderr,
-				"%.*s is not a valid attribute name: %s:%d\n",
-				namelen, name, src, lineno);
-			return NULL;
+		if (!attr_name_valid(name, namelen)) {
+			report_invalid_attr(name, namelen, src, lineno);
+			goto fail_return;
 		}
 	}
 	else
 		is_macro = 0;
 
-	states = name + namelen;
 	states += strspn(states, blank);
 
 	/* First pass to count the attr_states */
 	for (cp = states, num_attr = 0; *cp; num_attr++) {
 		cp = parse_attr(src, lineno, cp, NULL);
 		if (!cp)
-			return NULL;
+			goto fail_return;
 	}
 
 	res = xcalloc(1,
@@ -250,7 +396,6 @@
 		      (is_macro ? 0 : namelen + 1));
 	if (is_macro) {
 		res->u.attr = git_attr_internal(name, namelen);
-		res->u.attr->maybe_macro = 1;
 	} else {
 		char *p = (char *)&(res->state[num_attr]);
 		memcpy(p, name, namelen);
@@ -262,7 +407,7 @@
 		if (res->u.pat.flags & EXC_FLAG_NEGATIVE) {
 			warning(_("Negative patterns are ignored in git attributes\n"
 				  "Use '\\!' for literal leading exclamation."));
-			return NULL;
+			goto fail_return;
 		}
 	}
 	res->is_macro = is_macro;
@@ -271,13 +416,15 @@
 	/* Second pass to fill the attr_states */
 	for (cp = states, i = 0; *cp; i++) {
 		cp = parse_attr(src, lineno, cp, &(res->state[i]));
-		if (!is_macro)
-			res->state[i].attr->maybe_real = 1;
-		if (res->state[i].attr->maybe_macro)
-			cannot_trust_maybe_real = 1;
 	}
 
+	strbuf_release(&pattern);
 	return res;
+
+fail_return:
+	strbuf_release(&pattern);
+	free(res);
+	return NULL;
 }
 
 /*
@@ -295,19 +442,19 @@
  * directory (again, reading the file from top to bottom) down to the
  * current directory, and then scan the list backwards to find the first match.
  * This is exactly the same as what is_excluded() does in dir.c to deal with
- * .gitignore
+ * .gitignore file and info/excludes file as a fallback.
  */
 
-static struct attr_stack {
+struct attr_stack {
 	struct attr_stack *prev;
 	char *origin;
 	size_t originlen;
 	unsigned num_matches;
 	unsigned alloc;
 	struct match_attr **attrs;
-} *attr_stack;
+};
 
-static void free_attr_elem(struct attr_stack *e)
+static void attr_stack_free(struct attr_stack *e)
 {
 	int i;
 	free(e->origin);
@@ -330,6 +477,190 @@
 	free(e);
 }
 
+static void drop_attr_stack(struct attr_stack **stack)
+{
+	while (*stack) {
+		struct attr_stack *elem = *stack;
+		*stack = elem->prev;
+		attr_stack_free(elem);
+	}
+}
+
+/* List of all attr_check structs; access should be surrounded by mutex */
+static struct check_vector {
+	size_t nr;
+	size_t alloc;
+	struct attr_check **checks;
+#ifndef NO_PTHREADS
+	pthread_mutex_t mutex;
+#endif
+} check_vector;
+
+static inline void vector_lock(void)
+{
+#ifndef NO_PTHREADS
+	pthread_mutex_lock(&check_vector.mutex);
+#endif
+}
+
+static inline void vector_unlock(void)
+{
+#ifndef NO_PTHREADS
+	pthread_mutex_unlock(&check_vector.mutex);
+#endif
+}
+
+static void check_vector_add(struct attr_check *c)
+{
+	vector_lock();
+
+	ALLOC_GROW(check_vector.checks,
+		   check_vector.nr + 1,
+		   check_vector.alloc);
+	check_vector.checks[check_vector.nr++] = c;
+
+	vector_unlock();
+}
+
+static void check_vector_remove(struct attr_check *check)
+{
+	int i;
+
+	vector_lock();
+
+	/* Find entry */
+	for (i = 0; i < check_vector.nr; i++)
+		if (check_vector.checks[i] == check)
+			break;
+
+	if (i >= check_vector.nr)
+		die("BUG: no entry found");
+
+	/* shift entries over */
+	for (; i < check_vector.nr - 1; i++)
+		check_vector.checks[i] = check_vector.checks[i + 1];
+
+	check_vector.nr--;
+
+	vector_unlock();
+}
+
+/* Iterate through all attr_check instances and drop their stacks */
+static void drop_all_attr_stacks(void)
+{
+	int i;
+
+	vector_lock();
+
+	for (i = 0; i < check_vector.nr; i++) {
+		drop_attr_stack(&check_vector.checks[i]->stack);
+	}
+
+	vector_unlock();
+}
+
+struct attr_check *attr_check_alloc(void)
+{
+	struct attr_check *c = xcalloc(1, sizeof(struct attr_check));
+
+	/* save pointer to the check struct */
+	check_vector_add(c);
+
+	return c;
+}
+
+struct attr_check *attr_check_initl(const char *one, ...)
+{
+	struct attr_check *check;
+	int cnt;
+	va_list params;
+	const char *param;
+
+	va_start(params, one);
+	for (cnt = 1; (param = va_arg(params, const char *)) != NULL; cnt++)
+		;
+	va_end(params);
+
+	check = attr_check_alloc();
+	check->nr = cnt;
+	check->alloc = cnt;
+	check->items = xcalloc(cnt, sizeof(struct attr_check_item));
+
+	check->items[0].attr = git_attr(one);
+	va_start(params, one);
+	for (cnt = 1; cnt < check->nr; cnt++) {
+		const struct git_attr *attr;
+		param = va_arg(params, const char *);
+		if (!param)
+			die("BUG: counted %d != ended at %d",
+			    check->nr, cnt);
+		attr = git_attr(param);
+		if (!attr)
+			die("BUG: %s: not a valid attribute name", param);
+		check->items[cnt].attr = attr;
+	}
+	va_end(params);
+	return check;
+}
+
+struct attr_check *attr_check_dup(const struct attr_check *check)
+{
+	struct attr_check *ret;
+
+	if (!check)
+		return NULL;
+
+	ret = attr_check_alloc();
+
+	ret->nr = check->nr;
+	ret->alloc = check->alloc;
+	ALLOC_ARRAY(ret->items, ret->nr);
+	COPY_ARRAY(ret->items, check->items, ret->nr);
+
+	return ret;
+}
+
+struct attr_check_item *attr_check_append(struct attr_check *check,
+					  const struct git_attr *attr)
+{
+	struct attr_check_item *item;
+
+	ALLOC_GROW(check->items, check->nr + 1, check->alloc);
+	item = &check->items[check->nr++];
+	item->attr = attr;
+	return item;
+}
+
+void attr_check_reset(struct attr_check *check)
+{
+	check->nr = 0;
+}
+
+void attr_check_clear(struct attr_check *check)
+{
+	free(check->items);
+	check->items = NULL;
+	check->alloc = 0;
+	check->nr = 0;
+
+	free(check->all_attrs);
+	check->all_attrs = NULL;
+	check->all_attrs_nr = 0;
+
+	drop_attr_stack(&check->stack);
+}
+
+void attr_check_free(struct attr_check *check)
+{
+	if (check) {
+		/* Remove check from the check vector */
+		check_vector_remove(check);
+
+		attr_check_clear(check);
+		free(check);
+	}
+}
+
 static const char *builtin_attr[] = {
 	"[attr]binary -diff -merge -text",
 	NULL,
@@ -362,9 +693,31 @@
 	return res;
 }
 
+/*
+ * Callers into the attribute system assume there is a single, system-wide
+ * global state where attributes are read from and when the state is flipped by
+ * calling git_attr_set_direction(), the stack frames that have been
+ * constructed need to be discarded so so that subsequent calls into the
+ * attribute system will lazily read from the right place.  Since changing
+ * direction causes a global paradigm shift, it should not ever be called while
+ * another thread could potentially be calling into the attribute system.
+ */
 static enum git_attr_direction direction;
 static struct index_state *use_index;
 
+void git_attr_set_direction(enum git_attr_direction new_direction,
+			    struct index_state *istate)
+{
+	if (is_bare_repository() && new_direction != GIT_ATTR_INDEX)
+		die("BUG: non-INDEX attr direction in a bare repo");
+
+	if (new_direction != direction)
+		drop_all_attr_stacks();
+
+	direction = new_direction;
+	use_index = istate;
+}
+
 static struct attr_stack *read_attr_from_file(const char *path, int macro_ok)
 {
 	FILE *fp = fopen(path, "r");
@@ -402,8 +755,8 @@
 	for (sp = buf; *sp; ) {
 		char *ep;
 		int more;
-		for (ep = sp; *ep && *ep != '\n'; ep++)
-			;
+
+		ep = strchrnul(sp, '\n');
 		more = (*ep == '\n');
 		*ep = '\0';
 		handle_attr_line(res, sp, path, ++lineno, macro_ok);
@@ -415,25 +768,28 @@
 
 static struct attr_stack *read_attr(const char *path, int macro_ok)
 {
-	struct attr_stack *res;
+	struct attr_stack *res = NULL;
 
-	if (direction == GIT_ATTR_CHECKOUT) {
+	if (direction == GIT_ATTR_INDEX) {
 		res = read_attr_from_index(path, macro_ok);
-		if (!res)
-			res = read_attr_from_file(path, macro_ok);
-	}
-	else if (direction == GIT_ATTR_CHECKIN) {
-		res = read_attr_from_file(path, macro_ok);
-		if (!res)
-			/*
-			 * There is no checked out .gitattributes file there, but
-			 * we might have it in the index.  We allow operation in a
-			 * sparsely checked out work tree, so read from it.
-			 */
+	} else if (!is_bare_repository()) {
+		if (direction == GIT_ATTR_CHECKOUT) {
 			res = read_attr_from_index(path, macro_ok);
+			if (!res)
+				res = read_attr_from_file(path, macro_ok);
+		} else if (direction == GIT_ATTR_CHECKIN) {
+			res = read_attr_from_file(path, macro_ok);
+			if (!res)
+				/*
+				 * There is no checked out .gitattributes file
+				 * there, but we might have it in the index.
+				 * We allow operation in a sparsely checked out
+				 * work tree, so read from it.
+				 */
+				res = read_attr_from_index(path, macro_ok);
+		}
 	}
-	else
-		res = read_attr_from_index(path, macro_ok);
+
 	if (!res)
 		res = xcalloc(1, sizeof(*res));
 	return res;
@@ -464,16 +820,7 @@
 #define debug_push(a) do { ; } while (0)
 #define debug_pop(a) do { ; } while (0)
 #define debug_set(a,b,c,d) do { ; } while (0)
-#endif
-
-static void drop_attr_stack(void)
-{
-	while (attr_stack) {
-		struct attr_stack *elem = attr_stack;
-		attr_stack = elem->prev;
-		free_attr_elem(elem);
-	}
-}
+#endif /* DEBUG_ATTR */
 
 static const char *git_etc_gitattributes(void)
 {
@@ -483,6 +830,14 @@
 	return system_wide;
 }
 
+static const char *get_home_gitattributes(void)
+{
+	if (!git_attributes_file)
+		git_attributes_file = xdg_config_home("attributes");
+
+	return git_attributes_file;
+}
+
 static int git_attr_system(void)
 {
 	return !git_env_bool("GIT_ATTR_NOSYSTEM", 0);
@@ -490,64 +845,60 @@
 
 static GIT_PATH_FUNC(git_path_info_attributes, INFOATTRIBUTES_FILE)
 
-static void bootstrap_attr_stack(void)
+static void push_stack(struct attr_stack **attr_stack_p,
+		       struct attr_stack *elem, char *origin, size_t originlen)
 {
-	struct attr_stack *elem;
-
-	if (attr_stack)
-		return;
-
-	elem = read_attr_from_array(builtin_attr);
-	elem->origin = NULL;
-	elem->prev = attr_stack;
-	attr_stack = elem;
-
-	if (git_attr_system()) {
-		elem = read_attr_from_file(git_etc_gitattributes(), 1);
-		if (elem) {
-			elem->origin = NULL;
-			elem->prev = attr_stack;
-			attr_stack = elem;
-		}
+	if (elem) {
+		elem->origin = origin;
+		if (origin)
+			elem->originlen = originlen;
+		elem->prev = *attr_stack_p;
+		*attr_stack_p = elem;
 	}
-
-	if (!git_attributes_file)
-		git_attributes_file = xdg_config_home("attributes");
-	if (git_attributes_file) {
-		elem = read_attr_from_file(git_attributes_file, 1);
-		if (elem) {
-			elem->origin = NULL;
-			elem->prev = attr_stack;
-			attr_stack = elem;
-		}
-	}
-
-	if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
-		elem = read_attr(GITATTRIBUTES_FILE, 1);
-		elem->origin = xstrdup("");
-		elem->originlen = 0;
-		elem->prev = attr_stack;
-		attr_stack = elem;
-		debug_push(elem);
-	}
-
-	if (startup_info->have_repository)
-		elem = read_attr_from_file(git_path_info_attributes(), 1);
-	else
-		elem = NULL;
-
-	if (!elem)
-		elem = xcalloc(1, sizeof(*elem));
-	elem->origin = NULL;
-	elem->prev = attr_stack;
-	attr_stack = elem;
 }
 
-static void prepare_attr_stack(const char *path, int dirlen)
+static void bootstrap_attr_stack(struct attr_stack **stack)
 {
-	struct attr_stack *elem, *info;
-	int len;
-	const char *cp;
+	struct attr_stack *e;
+
+	if (*stack)
+		return;
+
+	/* builtin frame */
+	e = read_attr_from_array(builtin_attr);
+	push_stack(stack, e, NULL, 0);
+
+	/* system-wide frame */
+	if (git_attr_system()) {
+		e = read_attr_from_file(git_etc_gitattributes(), 1);
+		push_stack(stack, e, NULL, 0);
+	}
+
+	/* home directory */
+	if (get_home_gitattributes()) {
+		e = read_attr_from_file(get_home_gitattributes(), 1);
+		push_stack(stack, e, NULL, 0);
+	}
+
+	/* root directory */
+	e = read_attr(GITATTRIBUTES_FILE, 1);
+	push_stack(stack, e, xstrdup(""), 0);
+
+	/* info frame */
+	if (startup_info->have_repository)
+		e = read_attr_from_file(git_path_info_attributes(), 1);
+	else
+		e = NULL;
+	if (!e)
+		e = xcalloc(1, sizeof(struct attr_stack));
+	push_stack(stack, e, NULL, 0);
+}
+
+static void prepare_attr_stack(const char *path, int dirlen,
+			       struct attr_stack **stack)
+{
+	struct attr_stack *info;
+	struct strbuf pathbuf = STRBUF_INIT;
 
 	/*
 	 * At the bottom of the attribute stack is the built-in
@@ -564,13 +915,13 @@
 	 * .gitattributes in deeper directories to shallower ones,
 	 * and finally use the built-in set as the default.
 	 */
-	bootstrap_attr_stack();
+	bootstrap_attr_stack(stack);
 
 	/*
 	 * Pop the "info" one that is always at the top of the stack.
 	 */
-	info = attr_stack;
-	attr_stack = info->prev;
+	info = *stack;
+	*stack = info->prev;
 
 	/*
 	 * Pop the ones from directories that are not the prefix of
@@ -578,59 +929,63 @@
 	 * the root one (whose origin is an empty string "") or the builtin
 	 * one (whose origin is NULL) without popping it.
 	 */
-	while (attr_stack->origin) {
-		int namelen = strlen(attr_stack->origin);
+	while ((*stack)->origin) {
+		int namelen = (*stack)->originlen;
+		struct attr_stack *elem;
 
-		elem = attr_stack;
+		elem = *stack;
 		if (namelen <= dirlen &&
 		    !strncmp(elem->origin, path, namelen) &&
 		    (!namelen || path[namelen] == '/'))
 			break;
 
 		debug_pop(elem);
-		attr_stack = elem->prev;
-		free_attr_elem(elem);
+		*stack = elem->prev;
+		attr_stack_free(elem);
 	}
 
 	/*
-	 * Read from parent directories and push them down
+	 * bootstrap_attr_stack() should have added, and the
+	 * above loop should have stopped before popping, the
+	 * root element whose attr_stack->origin is set to an
+	 * empty string.
 	 */
-	if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
-		/*
-		 * bootstrap_attr_stack() should have added, and the
-		 * above loop should have stopped before popping, the
-		 * root element whose attr_stack->origin is set to an
-		 * empty string.
-		 */
-		struct strbuf pathbuf = STRBUF_INIT;
+	assert((*stack)->origin);
 
-		assert(attr_stack->origin);
-		while (1) {
-			len = strlen(attr_stack->origin);
-			if (dirlen <= len)
-				break;
-			cp = memchr(path + len + 1, '/', dirlen - len - 1);
-			if (!cp)
-				cp = path + dirlen;
-			strbuf_add(&pathbuf, path, cp - path);
+	strbuf_addstr(&pathbuf, (*stack)->origin);
+	/* Build up to the directory 'path' is in */
+	while (pathbuf.len < dirlen) {
+		size_t len = pathbuf.len;
+		struct attr_stack *next;
+		char *origin;
+
+		/* Skip path-separator */
+		if (len < dirlen && is_dir_sep(path[len]))
+			len++;
+		/* Find the end of the next component */
+		while (len < dirlen && !is_dir_sep(path[len]))
+			len++;
+
+		if (pathbuf.len > 0)
 			strbuf_addch(&pathbuf, '/');
-			strbuf_addstr(&pathbuf, GITATTRIBUTES_FILE);
-			elem = read_attr(pathbuf.buf, 0);
-			strbuf_setlen(&pathbuf, cp - path);
-			elem->origin = strbuf_detach(&pathbuf, &elem->originlen);
-			elem->prev = attr_stack;
-			attr_stack = elem;
-			debug_push(elem);
-		}
+		strbuf_add(&pathbuf, path + pathbuf.len, (len - pathbuf.len));
+		strbuf_addf(&pathbuf, "/%s", GITATTRIBUTES_FILE);
 
-		strbuf_release(&pathbuf);
+		next = read_attr(pathbuf.buf, 0);
+
+		/* reset the pathbuf to not include "/.gitattributes" */
+		strbuf_setlen(&pathbuf, len);
+
+		origin = xstrdup(pathbuf.buf);
+		push_stack(stack, next, origin, len);
 	}
 
 	/*
 	 * Finally push the "info" one at the top of the stack.
 	 */
-	info->prev = attr_stack;
-	attr_stack = info;
+	push_stack(stack, info, NULL, 0);
+
+	strbuf_release(&pathbuf);
 }
 
 static int path_matches(const char *pathname, int pathlen,
@@ -656,16 +1011,16 @@
 			      pattern, prefix, pat->patternlen, pat->flags);
 }
 
-static int macroexpand_one(int attr_nr, int rem);
+static int macroexpand_one(struct all_attrs_item *all_attrs, int nr, int rem);
 
-static int fill_one(const char *what, struct match_attr *a, int rem)
+static int fill_one(const char *what, struct all_attrs_item *all_attrs,
+		    const struct match_attr *a, int rem)
 {
-	struct git_attr_check *check = check_all_attr;
 	int i;
 
-	for (i = a->num_attr - 1; 0 < rem && 0 <= i; i--) {
-		struct git_attr *attr = a->state[i].attr;
-		const char **n = &(check[attr->attr_nr].value);
+	for (i = a->num_attr - 1; rem > 0 && i >= 0; i--) {
+		const struct git_attr *attr = a->state[i].attr;
+		const char **n = &(all_attrs[attr->attr_nr].value);
 		const char *v = a->state[i].setto;
 
 		if (*n == ATTR__UNKNOWN) {
@@ -674,64 +1029,72 @@
 				  attr, v);
 			*n = v;
 			rem--;
-			rem = macroexpand_one(attr->attr_nr, rem);
+			rem = macroexpand_one(all_attrs, attr->attr_nr, rem);
 		}
 	}
 	return rem;
 }
 
 static int fill(const char *path, int pathlen, int basename_offset,
-		struct attr_stack *stk, int rem)
+		const struct attr_stack *stack,
+		struct all_attrs_item *all_attrs, int rem)
 {
-	int i;
-	const char *base = stk->origin ? stk->origin : "";
+	for (; rem > 0 && stack; stack = stack->prev) {
+		int i;
+		const char *base = stack->origin ? stack->origin : "";
 
-	for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) {
-		struct match_attr *a = stk->attrs[i];
-		if (a->is_macro)
-			continue;
-		if (path_matches(path, pathlen, basename_offset,
-				 &a->u.pat, base, stk->originlen))
-			rem = fill_one("fill", a, rem);
+		for (i = stack->num_matches - 1; 0 < rem && 0 <= i; i--) {
+			const struct match_attr *a = stack->attrs[i];
+			if (a->is_macro)
+				continue;
+			if (path_matches(path, pathlen, basename_offset,
+					 &a->u.pat, base, stack->originlen))
+				rem = fill_one("fill", all_attrs, a, rem);
+		}
 	}
+
 	return rem;
 }
 
-static int macroexpand_one(int nr, int rem)
+static int macroexpand_one(struct all_attrs_item *all_attrs, int nr, int rem)
 {
-	struct attr_stack *stk;
-	struct match_attr *a = NULL;
-	int i;
+	const struct all_attrs_item *item = &all_attrs[nr];
 
-	if (check_all_attr[nr].value != ATTR__TRUE ||
-	    !check_all_attr[nr].attr->maybe_macro)
+	if (item->macro && item->value == ATTR__TRUE)
+		return fill_one("expand", all_attrs, item->macro, rem);
+	else
 		return rem;
-
-	for (stk = attr_stack; !a && stk; stk = stk->prev)
-		for (i = stk->num_matches - 1; !a && 0 <= i; i--) {
-			struct match_attr *ma = stk->attrs[i];
-			if (!ma->is_macro)
-				continue;
-			if (ma->u.attr->attr_nr == nr)
-				a = ma;
-		}
-
-	if (a)
-		rem = fill_one("expand", a, rem);
-
-	return rem;
 }
 
 /*
- * Collect attributes for path into the array pointed to by
- * check_all_attr. If num is non-zero, only attributes in check[] are
- * collected. Otherwise all attributes are collected.
+ * Marks the attributes which are macros based on the attribute stack.
+ * This prevents having to search through the attribute stack each time
+ * a macro needs to be expanded during the fill stage.
  */
-static void collect_some_attrs(const char *path, int num,
-			       struct git_attr_check *check)
-
+static void determine_macros(struct all_attrs_item *all_attrs,
+			     const struct attr_stack *stack)
 {
-	struct attr_stack *stk;
+	for (; stack; stack = stack->prev) {
+		int i;
+		for (i = stack->num_matches - 1; i >= 0; i--) {
+			const struct match_attr *ma = stack->attrs[i];
+			if (ma->is_macro) {
+				int n = ma->u.attr->attr_nr;
+				if (!all_attrs[n].macro) {
+					all_attrs[n].macro = ma;
+				}
+			}
+		}
+	}
+}
+
+/*
+ * Collect attributes for path into the array pointed to by check->all_attrs.
+ * If check->check_nr is non-zero, only attributes in check[] are collected.
+ * Otherwise all attributes are collected.
+ */
+static void collect_some_attrs(const char *path, struct attr_check *check)
+{
 	int i, pathlen, rem, dirlen;
 	const char *cp, *last_slash = NULL;
 	int basename_offset;
@@ -749,81 +1112,67 @@
 		dirlen = 0;
 	}
 
-	prepare_attr_stack(path, dirlen);
-	for (i = 0; i < attr_nr; i++)
-		check_all_attr[i].value = ATTR__UNKNOWN;
-	if (num && !cannot_trust_maybe_real) {
+	prepare_attr_stack(path, dirlen, &check->stack);
+	all_attrs_init(&g_attr_hashmap, check);
+	determine_macros(check->all_attrs, check->stack);
+
+	if (check->nr) {
 		rem = 0;
-		for (i = 0; i < num; i++) {
-			if (!check[i].attr->maybe_real) {
-				struct git_attr_check *c;
-				c = check_all_attr + check[i].attr->attr_nr;
-				c->value = ATTR__UNSET;
+		for (i = 0; i < check->nr; i++) {
+			int n = check->items[i].attr->attr_nr;
+			struct all_attrs_item *item = &check->all_attrs[n];
+			if (item->macro) {
+				item->value = ATTR__UNSET;
 				rem++;
 			}
 		}
-		if (rem == num)
+		if (rem == check->nr)
 			return;
 	}
 
-	rem = attr_nr;
-	for (stk = attr_stack; 0 < rem && stk; stk = stk->prev)
-		rem = fill(path, pathlen, basename_offset, stk, rem);
+	rem = check->all_attrs_nr;
+	fill(path, pathlen, basename_offset, check->stack, check->all_attrs, rem);
 }
 
-int git_check_attr(const char *path, int num, struct git_attr_check *check)
+int git_check_attr(const char *path, struct attr_check *check)
 {
 	int i;
 
-	collect_some_attrs(path, num, check);
+	collect_some_attrs(path, check);
 
-	for (i = 0; i < num; i++) {
-		const char *value = check_all_attr[check[i].attr->attr_nr].value;
+	for (i = 0; i < check->nr; i++) {
+		size_t n = check->items[i].attr->attr_nr;
+		const char *value = check->all_attrs[n].value;
 		if (value == ATTR__UNKNOWN)
 			value = ATTR__UNSET;
-		check[i].value = value;
+		check->items[i].value = value;
 	}
 
 	return 0;
 }
 
-int git_all_attrs(const char *path, int *num, struct git_attr_check **check)
+void git_all_attrs(const char *path, struct attr_check *check)
 {
-	int i, count, j;
+	int i;
 
-	collect_some_attrs(path, 0, NULL);
+	attr_check_reset(check);
+	collect_some_attrs(path, check);
 
-	/* Count the number of attributes that are set. */
-	count = 0;
-	for (i = 0; i < attr_nr; i++) {
-		const char *value = check_all_attr[i].value;
-		if (value != ATTR__UNSET && value != ATTR__UNKNOWN)
-			++count;
+	for (i = 0; i < check->all_attrs_nr; i++) {
+		const char *name = check->all_attrs[i].attr->name;
+		const char *value = check->all_attrs[i].value;
+		struct attr_check_item *item;
+		if (value == ATTR__UNSET || value == ATTR__UNKNOWN)
+			continue;
+		item = attr_check_append(check, git_attr(name));
+		item->value = value;
 	}
-	*num = count;
-	ALLOC_ARRAY(*check, count);
-	j = 0;
-	for (i = 0; i < attr_nr; i++) {
-		const char *value = check_all_attr[i].value;
-		if (value != ATTR__UNSET && value != ATTR__UNKNOWN) {
-			(*check)[j].attr = check_all_attr[i].attr;
-			(*check)[j].value = value;
-			++j;
-		}
-	}
-
-	return 0;
 }
 
-void git_attr_set_direction(enum git_attr_direction new, struct index_state *istate)
+void attr_start(void)
 {
-	enum git_attr_direction old = direction;
-
-	if (is_bare_repository() && new != GIT_ATTR_INDEX)
-		die("BUG: non-INDEX attr direction in a bare repo");
-
-	direction = new;
-	if (new != old)
-		drop_attr_stack();
-	use_index = istate;
+#ifndef NO_PTHREADS
+	pthread_mutex_init(&g_attr_hashmap.mutex, NULL);
+	pthread_mutex_init(&check_vector.mutex, NULL);
+#endif
 }
diff --git a/attr.h b/attr.h
index 8b08d33..442d464 100644
--- a/attr.h
+++ b/attr.h
@@ -4,11 +4,15 @@
 /* An attribute is a pointer to this opaque structure */
 struct git_attr;
 
+/* opaque structures used internally for attribute collection */
+struct all_attrs_item;
+struct attr_stack;
+
 /*
  * Given a string, return the gitattribute object that
  * corresponds to it.
  */
-struct git_attr *git_attr(const char *);
+const struct git_attr *git_attr(const char *);
 
 /* Internal use */
 extern const char git_attr__true[];
@@ -20,38 +24,58 @@
 #define ATTR_UNSET(v) ((v) == NULL)
 
 /*
- * Send one or more git_attr_check to git_check_attr(), and
+ * Send one or more git_attr_check to git_check_attrs(), and
  * each 'value' member tells what its value is.
  * Unset one is returned as NULL.
  */
-struct git_attr_check {
-	struct git_attr *attr;
+struct attr_check_item {
+	const struct git_attr *attr;
 	const char *value;
 };
 
+struct attr_check {
+	int nr;
+	int alloc;
+	struct attr_check_item *items;
+	int all_attrs_nr;
+	struct all_attrs_item *all_attrs;
+	struct attr_stack *stack;
+};
+
+extern struct attr_check *attr_check_alloc(void);
+extern struct attr_check *attr_check_initl(const char *, ...);
+extern struct attr_check *attr_check_dup(const struct attr_check *check);
+
+extern struct attr_check_item *attr_check_append(struct attr_check *check,
+						 const struct git_attr *attr);
+
+extern void attr_check_reset(struct attr_check *check);
+extern void attr_check_clear(struct attr_check *check);
+extern void attr_check_free(struct attr_check *check);
+
 /*
  * Return the name of the attribute represented by the argument.  The
  * return value is a pointer to a null-delimited string that is part
  * of the internal data structure; it should not be modified or freed.
  */
-char *git_attr_name(struct git_attr *);
+extern const char *git_attr_name(const struct git_attr *);
 
-int git_check_attr(const char *path, int, struct git_attr_check *);
+extern int git_check_attr(const char *path, struct attr_check *check);
 
 /*
- * Retrieve all attributes that apply to the specified path.  *num
- * will be set to the number of attributes on the path; **check will
- * be set to point at a newly-allocated array of git_attr_check
- * objects describing the attributes and their values.  *check must be
- * free()ed by the caller.
+ * Retrieve all attributes that apply to the specified path.
+ * check holds the attributes and their values.
  */
-int git_all_attrs(const char *path, int *num, struct git_attr_check **check);
+extern void git_all_attrs(const char *path, struct attr_check *check);
 
 enum git_attr_direction {
 	GIT_ATTR_CHECKIN,
 	GIT_ATTR_CHECKOUT,
 	GIT_ATTR_INDEX
 };
-void git_attr_set_direction(enum git_attr_direction, struct index_state *);
+void git_attr_set_direction(enum git_attr_direction new_direction,
+			    struct index_state *istate);
+
+extern void attr_start(void);
 
 #endif /* ATTR_H */
diff --git a/bisect.c b/bisect.c
index 8e63c40..30808ca 100644
--- a/bisect.c
+++ b/bisect.c
@@ -940,7 +940,7 @@
 	struct commit_list *tried;
 	int reaches = 0, all = 0, nr, steps;
 	const unsigned char *bisect_rev;
-	char steps_msg[32];
+	char *steps_msg;
 
 	read_bisect_terms(&term_bad, &term_good);
 	if (read_bisect_refs())
@@ -990,14 +990,15 @@
 
 	nr = all - reaches - 1;
 	steps = estimate_bisect_steps(all);
-	xsnprintf(steps_msg, sizeof(steps_msg),
-		  Q_("(roughly %d step)", "(roughly %d steps)", steps),
-		  steps);
+
+	steps_msg = xstrfmt(Q_("(roughly %d step)", "(roughly %d steps)",
+		  steps), steps);
 	/* TRANSLATORS: the last %s will be replaced with
 	   "(roughly %d steps)" translation */
 	printf(Q_("Bisecting: %d revision left to test after this %s\n",
 		  "Bisecting: %d revisions left to test after this %s\n",
 		  nr), nr, steps_msg);
+	free(steps_msg);
 
 	return bisect_checkout(bisect_rev, no_checkout);
 }
diff --git a/branch.c b/branch.c
index b955d4f..5c12036 100644
--- a/branch.c
+++ b/branch.c
@@ -345,7 +345,8 @@
 	    branch, wt->path);
 }
 
-int replace_each_worktree_head_symref(const char *oldref, const char *newref)
+int replace_each_worktree_head_symref(const char *oldref, const char *newref,
+				      const char *logmsg)
 {
 	int ret = 0;
 	struct worktree **worktrees = get_worktrees(0);
@@ -358,7 +359,7 @@
 			continue;
 
 		if (set_worktree_head_symref(get_worktree_git_dir(worktrees[i]),
-					     newref)) {
+					     newref, logmsg)) {
 			ret = -1;
 			error(_("HEAD of working tree %s is not updated"),
 			      worktrees[i]->path);
diff --git a/branch.h b/branch.h
index 3103eb9..b077885 100644
--- a/branch.h
+++ b/branch.h
@@ -71,6 +71,7 @@
  * This will be used when renaming a branch. Returns 0 if successful, non-zero
  * otherwise.
  */
-extern int replace_each_worktree_head_symref(const char *oldref, const char *newref);
+extern int replace_each_worktree_head_symref(const char *oldref, const char *newref,
+					     const char *logmsg);
 
 #endif
diff --git a/builtin.h b/builtin.h
index 67f8051..9e4a898 100644
--- a/builtin.h
+++ b/builtin.h
@@ -103,6 +103,7 @@
 extern int cmd_pull(int argc, const char **argv, const char *prefix);
 extern int cmd_push(int argc, const char **argv, const char *prefix);
 extern int cmd_read_tree(int argc, const char **argv, const char *prefix);
+extern int cmd_rebase__helper(int argc, const char **argv, const char *prefix);
 extern int cmd_receive_pack(int argc, const char **argv, const char *prefix);
 extern int cmd_reflog(int argc, const char **argv, const char *prefix);
 extern int cmd_remote(int argc, const char **argv, const char *prefix);
diff --git a/builtin/am.c b/builtin/am.c
index 31fb605..f7a7a97 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -1049,7 +1049,7 @@
 	} else {
 		write_state_text(state, "abort-safety", "");
 		if (!state->rebasing)
-			delete_ref("ORIG_HEAD", NULL, 0);
+			delete_ref(NULL, "ORIG_HEAD", NULL, 0);
 	}
 
 	/*
@@ -2172,7 +2172,7 @@
 				has_curr_head ? &curr_head : NULL, 0,
 				UPDATE_REFS_DIE_ON_ERR);
 	else if (curr_branch)
-		delete_ref(curr_branch, NULL, REF_NODEREF);
+		delete_ref(NULL, curr_branch, NULL, REF_NODEREF);
 
 	free(curr_branch);
 	am_destroy(state);
diff --git a/builtin/blame.c b/builtin/blame.c
index cffc626..f7aa95f 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -658,8 +658,11 @@
 /*
  * Append a new blame entry to a given output queue.
  */
-static void add_blame_entry(struct blame_entry ***queue, struct blame_entry *e)
+static void add_blame_entry(struct blame_entry ***queue,
+			    const struct blame_entry *src)
 {
+	struct blame_entry *e = xmalloc(sizeof(*e));
+	memcpy(e, src, sizeof(*e));
 	origin_incref(e->suspect);
 
 	e->next = **queue;
@@ -760,21 +763,15 @@
 			struct blame_entry *split,
 			struct blame_entry *e)
 {
-	struct blame_entry *new_entry;
-
 	if (split[0].suspect && split[2].suspect) {
 		/* The first part (reuse storage for the existing entry e) */
 		dup_entry(unblamed, e, &split[0]);
 
 		/* The last part -- me */
-		new_entry = xmalloc(sizeof(*new_entry));
-		memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
-		add_blame_entry(unblamed, new_entry);
+		add_blame_entry(unblamed, &split[2]);
 
 		/* ... and the middle part -- parent */
-		new_entry = xmalloc(sizeof(*new_entry));
-		memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
-		add_blame_entry(blamed, new_entry);
+		add_blame_entry(blamed, &split[1]);
 	}
 	else if (!split[0].suspect && !split[2].suspect)
 		/*
@@ -785,18 +782,12 @@
 	else if (split[0].suspect) {
 		/* me and then parent */
 		dup_entry(unblamed, e, &split[0]);
-
-		new_entry = xmalloc(sizeof(*new_entry));
-		memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
-		add_blame_entry(blamed, new_entry);
+		add_blame_entry(blamed, &split[1]);
 	}
 	else {
 		/* parent and then me */
 		dup_entry(blamed, e, &split[1]);
-
-		new_entry = xmalloc(sizeof(*new_entry));
-		memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
-		add_blame_entry(unblamed, new_entry);
+		add_blame_entry(unblamed, &split[2]);
 	}
 }
 
diff --git a/builtin/branch.c b/builtin/branch.c
index 9d30f55..52688f2 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -28,20 +28,21 @@
 	N_("git branch [<options>] [-r] (-d | -D) <branch-name>..."),
 	N_("git branch [<options>] (-m | -M) [<old-branch>] <new-branch>"),
 	N_("git branch [<options>] [-r | -a] [--points-at]"),
+	N_("git branch [<options>] [-r | -a] [--format]"),
 	NULL
 };
 
 static const char *head;
-static unsigned char head_sha1[20];
+static struct object_id head_oid;
 
 static int branch_use_color = -1;
 static char branch_colors[][COLOR_MAXLEN] = {
 	GIT_COLOR_RESET,
-	GIT_COLOR_NORMAL,	/* PLAIN */
-	GIT_COLOR_RED,		/* REMOTE */
-	GIT_COLOR_NORMAL,	/* LOCAL */
-	GIT_COLOR_GREEN,	/* CURRENT */
-	GIT_COLOR_BLUE,		/* UPSTREAM */
+	GIT_COLOR_NORMAL,       /* PLAIN */
+	GIT_COLOR_RED,          /* REMOTE */
+	GIT_COLOR_NORMAL,       /* LOCAL */
+	GIT_COLOR_GREEN,        /* CURRENT */
+	GIT_COLOR_BLUE,         /* UPSTREAM */
 };
 enum color_branch {
 	BRANCH_COLOR_RESET = 0,
@@ -117,13 +118,13 @@
 	if (kind == FILTER_REFS_BRANCHES) {
 		struct branch *branch = branch_get(name);
 		const char *upstream = branch_get_upstream(branch, NULL);
-		unsigned char sha1[20];
+		struct object_id oid;
 
 		if (upstream &&
 		    (reference_name = reference_name_to_free =
 		     resolve_refdup(upstream, RESOLVE_REF_READING,
-				    sha1, NULL)) != NULL)
-			reference_rev = lookup_commit_reference(sha1);
+				    oid.hash, NULL)) != NULL)
+			reference_rev = lookup_commit_reference(oid.hash);
 	}
 	if (!reference_rev)
 		reference_rev = head_rev;
@@ -153,10 +154,10 @@
 }
 
 static int check_branch_commit(const char *branchname, const char *refname,
-			       const unsigned char *sha1, struct commit *head_rev,
+			       const struct object_id *oid, struct commit *head_rev,
 			       int kinds, int force)
 {
-	struct commit *rev = lookup_commit_reference(sha1);
+	struct commit *rev = lookup_commit_reference(oid->hash);
 	if (!rev) {
 		error(_("Couldn't look up commit object for '%s'"), refname);
 		return -1;
@@ -183,31 +184,34 @@
 			   int quiet)
 {
 	struct commit *head_rev = NULL;
-	unsigned char sha1[20];
+	struct object_id oid;
 	char *name = NULL;
 	const char *fmt;
 	int i;
 	int ret = 0;
 	int remote_branch = 0;
 	struct strbuf bname = STRBUF_INIT;
+	unsigned allowed_interpret;
 
 	switch (kinds) {
 	case FILTER_REFS_REMOTES:
 		fmt = "refs/remotes/%s";
 		/* For subsequent UI messages */
 		remote_branch = 1;
+		allowed_interpret = INTERPRET_BRANCH_REMOTE;
 
 		force = 1;
 		break;
 	case FILTER_REFS_BRANCHES:
 		fmt = "refs/heads/%s";
+		allowed_interpret = INTERPRET_BRANCH_LOCAL;
 		break;
 	default:
 		die(_("cannot use -a with -d"));
 	}
 
 	if (!force) {
-		head_rev = lookup_commit_reference(head_sha1);
+		head_rev = lookup_commit_reference(head_oid.hash);
 		if (!head_rev)
 			die(_("Couldn't look up commit object for HEAD"));
 	}
@@ -215,7 +219,7 @@
 		char *target = NULL;
 		int flags = 0;
 
-		strbuf_branchname(&bname, argv[i]);
+		strbuf_branchname(&bname, argv[i], allowed_interpret);
 		free(name);
 		name = mkpathdup(fmt, bname.buf);
 
@@ -235,7 +239,7 @@
 					RESOLVE_REF_READING
 					| RESOLVE_REF_NO_RECURSE
 					| RESOLVE_REF_ALLOW_BAD_NAME,
-					sha1, &flags);
+					oid.hash, &flags);
 		if (!target) {
 			error(remote_branch
 			      ? _("remote-tracking branch '%s' not found.")
@@ -245,13 +249,13 @@
 		}
 
 		if (!(flags & (REF_ISSYMREF|REF_ISBROKEN)) &&
-		    check_branch_commit(bname.buf, name, sha1, head_rev, kinds,
+		    check_branch_commit(bname.buf, name, &oid, head_rev, kinds,
 					force)) {
 			ret = 1;
 			goto next;
 		}
 
-		if (delete_ref(name, is_null_sha1(sha1) ? NULL : sha1,
+		if (delete_ref(NULL, name, is_null_oid(&oid) ? NULL : oid.hash,
 			       REF_NODEREF)) {
 			error(remote_branch
 			      ? _("Error deleting remote-tracking branch '%s'")
@@ -267,7 +271,7 @@
 			       bname.buf,
 			       (flags & REF_ISBROKEN) ? "broken"
 			       : (flags & REF_ISSYMREF) ? target
-			       : find_unique_abbrev(sha1, DEFAULT_ABBREV));
+			       : find_unique_abbrev(oid.hash, DEFAULT_ABBREV));
 		}
 		delete_branch_config(bname.buf);
 
@@ -280,195 +284,6 @@
 	return(ret);
 }
 
-static void fill_tracking_info(struct strbuf *stat, const char *branch_name,
-		int show_upstream_ref)
-{
-	int ours, theirs;
-	char *ref = NULL;
-	struct branch *branch = branch_get(branch_name);
-	const char *upstream;
-	struct strbuf fancy = STRBUF_INIT;
-	int upstream_is_gone = 0;
-	int added_decoration = 1;
-
-	if (stat_tracking_info(branch, &ours, &theirs, &upstream) < 0) {
-		if (!upstream)
-			return;
-		upstream_is_gone = 1;
-	}
-
-	if (show_upstream_ref) {
-		ref = shorten_unambiguous_ref(upstream, 0);
-		if (want_color(branch_use_color))
-			strbuf_addf(&fancy, "%s%s%s",
-					branch_get_color(BRANCH_COLOR_UPSTREAM),
-					ref, branch_get_color(BRANCH_COLOR_RESET));
-		else
-			strbuf_addstr(&fancy, ref);
-	}
-
-	if (upstream_is_gone) {
-		if (show_upstream_ref)
-			strbuf_addf(stat, _("[%s: gone]"), fancy.buf);
-		else
-			added_decoration = 0;
-	} else if (!ours && !theirs) {
-		if (show_upstream_ref)
-			strbuf_addf(stat, _("[%s]"), fancy.buf);
-		else
-			added_decoration = 0;
-	} else if (!ours) {
-		if (show_upstream_ref)
-			strbuf_addf(stat, _("[%s: behind %d]"), fancy.buf, theirs);
-		else
-			strbuf_addf(stat, _("[behind %d]"), theirs);
-
-	} else if (!theirs) {
-		if (show_upstream_ref)
-			strbuf_addf(stat, _("[%s: ahead %d]"), fancy.buf, ours);
-		else
-			strbuf_addf(stat, _("[ahead %d]"), ours);
-	} else {
-		if (show_upstream_ref)
-			strbuf_addf(stat, _("[%s: ahead %d, behind %d]"),
-				    fancy.buf, ours, theirs);
-		else
-			strbuf_addf(stat, _("[ahead %d, behind %d]"),
-				    ours, theirs);
-	}
-	strbuf_release(&fancy);
-	if (added_decoration)
-		strbuf_addch(stat, ' ');
-	free(ref);
-}
-
-static void add_verbose_info(struct strbuf *out, struct ref_array_item *item,
-			     struct ref_filter *filter, const char *refname)
-{
-	struct strbuf subject = STRBUF_INIT, stat = STRBUF_INIT;
-	const char *sub = _(" **** invalid ref ****");
-	struct commit *commit = item->commit;
-
-	if (!parse_commit(commit)) {
-		pp_commit_easy(CMIT_FMT_ONELINE, commit, &subject);
-		sub = subject.buf;
-	}
-
-	if (item->kind == FILTER_REFS_BRANCHES)
-		fill_tracking_info(&stat, refname, filter->verbose > 1);
-
-	strbuf_addf(out, " %s %s%s",
-		find_unique_abbrev(item->commit->object.oid.hash, filter->abbrev),
-		stat.buf, sub);
-	strbuf_release(&stat);
-	strbuf_release(&subject);
-}
-
-static char *get_head_description(void)
-{
-	struct strbuf desc = STRBUF_INIT;
-	struct wt_status_state state;
-	memset(&state, 0, sizeof(state));
-	wt_status_get_state(&state, 1);
-	if (state.rebase_in_progress ||
-	    state.rebase_interactive_in_progress)
-		strbuf_addf(&desc, _("(no branch, rebasing %s)"),
-			    state.branch);
-	else if (state.bisect_in_progress)
-		strbuf_addf(&desc, _("(no branch, bisect started on %s)"),
-			    state.branch);
-	else if (state.detached_from) {
-		if (state.detached_at)
-			/* TRANSLATORS: make sure this matches
-			   "HEAD detached at " in wt-status.c */
-			strbuf_addf(&desc, _("(HEAD detached at %s)"),
-				state.detached_from);
-		else
-			/* TRANSLATORS: make sure this matches
-			   "HEAD detached from " in wt-status.c */
-			strbuf_addf(&desc, _("(HEAD detached from %s)"),
-				state.detached_from);
-	}
-	else
-		strbuf_addstr(&desc, _("(no branch)"));
-	free(state.branch);
-	free(state.onto);
-	free(state.detached_from);
-	return strbuf_detach(&desc, NULL);
-}
-
-static void format_and_print_ref_item(struct ref_array_item *item, int maxwidth,
-				      struct ref_filter *filter, const char *remote_prefix)
-{
-	char c;
-	int current = 0;
-	int color;
-	struct strbuf out = STRBUF_INIT, name = STRBUF_INIT;
-	const char *prefix_to_show = "";
-	const char *prefix_to_skip = NULL;
-	const char *desc = item->refname;
-	char *to_free = NULL;
-
-	switch (item->kind) {
-	case FILTER_REFS_BRANCHES:
-		prefix_to_skip = "refs/heads/";
-		skip_prefix(desc, prefix_to_skip, &desc);
-		if (!filter->detached && !strcmp(desc, head))
-			current = 1;
-		else
-			color = BRANCH_COLOR_LOCAL;
-		break;
-	case FILTER_REFS_REMOTES:
-		prefix_to_skip = "refs/remotes/";
-		skip_prefix(desc, prefix_to_skip, &desc);
-		color = BRANCH_COLOR_REMOTE;
-		prefix_to_show = remote_prefix;
-		break;
-	case FILTER_REFS_DETACHED_HEAD:
-		desc = to_free = get_head_description();
-		current = 1;
-		break;
-	default:
-		color = BRANCH_COLOR_PLAIN;
-		break;
-	}
-
-	c = ' ';
-	if (current) {
-		c = '*';
-		color = BRANCH_COLOR_CURRENT;
-	}
-
-	strbuf_addf(&name, "%s%s", prefix_to_show, desc);
-	if (filter->verbose) {
-		int utf8_compensation = strlen(name.buf) - utf8_strwidth(name.buf);
-		strbuf_addf(&out, "%c %s%-*s%s", c, branch_get_color(color),
-			    maxwidth + utf8_compensation, name.buf,
-			    branch_get_color(BRANCH_COLOR_RESET));
-	} else
-		strbuf_addf(&out, "%c %s%s%s", c, branch_get_color(color),
-			    name.buf, branch_get_color(BRANCH_COLOR_RESET));
-
-	if (item->symref) {
-		const char *symref = item->symref;
-		if (prefix_to_skip)
-			skip_prefix(symref, prefix_to_skip, &symref);
-		strbuf_addf(&out, " -> %s", symref);
-	}
-	else if (filter->verbose)
-		/* " f7c0c00 [ahead 58, behind 197] vcs-svn: drop obj_pool.h" */
-		add_verbose_info(&out, item, filter, desc);
-	if (column_active(colopts)) {
-		assert(!filter->verbose && "--column and --verbose are incompatible");
-		string_list_append(&output, out.buf);
-	} else {
-		printf("%s\n", out.buf);
-	}
-	strbuf_release(&name);
-	strbuf_release(&out);
-	free(to_free);
-}
-
 static int calc_maxwidth(struct ref_array *refs, int remote_bonus)
 {
 	int i, max = 0;
@@ -479,7 +294,12 @@
 
 		skip_prefix(it->refname, "refs/heads/", &desc);
 		skip_prefix(it->refname, "refs/remotes/", &desc);
-		w = utf8_strwidth(desc);
+		if (it->kind == FILTER_REFS_DETACHED_HEAD) {
+			char *head_desc = get_head_description();
+			w = utf8_strwidth(head_desc);
+			free(head_desc);
+		} else
+			w = utf8_strwidth(desc);
 
 		if (it->kind == FILTER_REFS_REMOTES)
 			w += remote_bonus;
@@ -489,12 +309,84 @@
 	return max;
 }
 
-static void print_ref_list(struct ref_filter *filter, struct ref_sorting *sorting)
+static const char *quote_literal_for_format(const char *s)
+{
+	static struct strbuf buf = STRBUF_INIT;
+
+	strbuf_reset(&buf);
+	while (*s) {
+		const char *ep = strchrnul(s, '%');
+		if (s < ep)
+			strbuf_add(&buf, s, ep - s);
+		if (*ep == '%') {
+			strbuf_addstr(&buf, "%%");
+			s = ep + 1;
+		} else {
+			s = ep;
+		}
+	}
+	return buf.buf;
+}
+
+static char *build_format(struct ref_filter *filter, int maxwidth, const char *remote_prefix)
+{
+	struct strbuf fmt = STRBUF_INIT;
+	struct strbuf local = STRBUF_INIT;
+	struct strbuf remote = STRBUF_INIT;
+
+	strbuf_addf(&fmt, "%%(if)%%(HEAD)%%(then)* %s%%(else)  %%(end)",
+		    branch_get_color(BRANCH_COLOR_CURRENT));
+
+	if (filter->verbose) {
+		struct strbuf obname = STRBUF_INIT;
+
+		if (filter->abbrev < 0)
+			strbuf_addf(&obname, "%%(objectname:short)");
+		else if (!filter->abbrev)
+			strbuf_addf(&obname, "%%(objectname)");
+		else
+			strbuf_addf(&obname, "%%(objectname:short=%d)", filter->abbrev);
+
+		strbuf_addf(&local, "%%(align:%d,left)%%(refname:lstrip=2)%%(end)", maxwidth);
+		strbuf_addf(&local, "%s", branch_get_color(BRANCH_COLOR_RESET));
+		strbuf_addf(&local, " %s ", obname.buf);
+
+		if (filter->verbose > 1)
+			strbuf_addf(&local, "%%(if)%%(upstream)%%(then)[%s%%(upstream:short)%s%%(if)%%(upstream:track)"
+				    "%%(then): %%(upstream:track,nobracket)%%(end)] %%(end)%%(contents:subject)",
+				    branch_get_color(BRANCH_COLOR_UPSTREAM), branch_get_color(BRANCH_COLOR_RESET));
+		else
+			strbuf_addf(&local, "%%(if)%%(upstream:track)%%(then)%%(upstream:track) %%(end)%%(contents:subject)");
+
+		strbuf_addf(&remote, "%s%%(align:%d,left)%s%%(refname:lstrip=2)%%(end)%s"
+			    "%%(if)%%(symref)%%(then) -> %%(symref:short)"
+			    "%%(else) %s %%(contents:subject)%%(end)",
+			    branch_get_color(BRANCH_COLOR_REMOTE), maxwidth, quote_literal_for_format(remote_prefix),
+			    branch_get_color(BRANCH_COLOR_RESET), obname.buf);
+		strbuf_release(&obname);
+	} else {
+		strbuf_addf(&local, "%%(refname:lstrip=2)%s%%(if)%%(symref)%%(then) -> %%(symref:short)%%(end)",
+			    branch_get_color(BRANCH_COLOR_RESET));
+		strbuf_addf(&remote, "%s%s%%(refname:lstrip=2)%s%%(if)%%(symref)%%(then) -> %%(symref:short)%%(end)",
+			    branch_get_color(BRANCH_COLOR_REMOTE), quote_literal_for_format(remote_prefix),
+			    branch_get_color(BRANCH_COLOR_RESET));
+	}
+
+	strbuf_addf(&fmt, "%%(if:notequals=refs/remotes)%%(refname:rstrip=-2)%%(then)%s%%(else)%s%%(end)", local.buf, remote.buf);
+
+	strbuf_release(&local);
+	strbuf_release(&remote);
+	return strbuf_detach(&fmt, NULL);
+}
+
+static void print_ref_list(struct ref_filter *filter, struct ref_sorting *sorting, const char *format)
 {
 	int i;
 	struct ref_array array;
 	int maxwidth = 0;
 	const char *remote_prefix = "";
+	struct strbuf out = STRBUF_INIT;
+	char *to_free = NULL;
 
 	/*
 	 * If we are listing more than just remote branches,
@@ -506,18 +398,32 @@
 
 	memset(&array, 0, sizeof(array));
 
-	verify_ref_format("%(refname)%(symref)");
 	filter_refs(&array, filter, filter->kind | FILTER_REFS_INCLUDE_BROKEN);
 
 	if (filter->verbose)
 		maxwidth = calc_maxwidth(&array, strlen(remote_prefix));
 
+	if (!format)
+		format = to_free = build_format(filter, maxwidth, remote_prefix);
+	verify_ref_format(format);
+
 	ref_array_sort(sorting, &array);
 
-	for (i = 0; i < array.nr; i++)
-		format_and_print_ref_item(array.items[i], maxwidth, filter, remote_prefix);
+	for (i = 0; i < array.nr; i++) {
+		format_ref_array_item(array.items[i], format, 0, &out);
+		if (column_active(colopts)) {
+			assert(!filter->verbose && "--column and --verbose are incompatible");
+			 /* format to a string_list to let print_columns() do its job */
+			string_list_append(&output, out.buf);
+		} else {
+			fwrite(out.buf, 1, out.len, stdout);
+			putchar('\n');
+		}
+		strbuf_release(&out);
+	}
 
 	ref_array_clear(&array);
+	free(to_free);
 }
 
 static void reject_rebase_or_bisect_branch(const char *target)
@@ -579,14 +485,15 @@
 
 	if (rename_ref(oldref.buf, newref.buf, logmsg.buf))
 		die(_("Branch rename failed"));
-	strbuf_release(&logmsg);
 
 	if (recovery)
 		warning(_("Renamed a misnamed branch '%s' away"), oldref.buf + 11);
 
-	if (replace_each_worktree_head_symref(oldref.buf, newref.buf))
+	if (replace_each_worktree_head_symref(oldref.buf, newref.buf, logmsg.buf))
 		die(_("Branch renamed to %s, but HEAD is not updated!"), newname);
 
+	strbuf_release(&logmsg);
+
 	strbuf_addf(&oldsection, "branch.%s", oldref.buf + 11);
 	strbuf_release(&oldref);
 	strbuf_addf(&newsection, "branch.%s", newref.buf + 11);
@@ -638,6 +545,7 @@
 	struct ref_filter filter;
 	int icase = 0;
 	static struct ref_sorting *sorting = NULL, **sorting_tail = &sorting;
+	const char *format = NULL;
 
 	struct option options[] = {
 		OPT_GROUP(N_("Generic options")),
@@ -679,9 +587,12 @@
 			N_("print only branches of the object"), 0, parse_opt_object_name
 		},
 		OPT_BOOL('i', "ignore-case", &icase, N_("sorting and filtering are case insensitive")),
+		OPT_STRING(  0 , "format", &format, N_("format"), N_("format to use for the output")),
 		OPT_END(),
 	};
 
+	setup_ref_filter_porcelain_msg();
+
 	memset(&filter, 0, sizeof(filter));
 	filter.kind = FILTER_REFS_BRANCHES;
 	filter.abbrev = -1;
@@ -693,7 +604,7 @@
 
 	track = git_branch_track;
 
-	head = resolve_refdup("HEAD", 0, head_sha1, NULL);
+	head = resolve_refdup("HEAD", 0, head_oid.hash, NULL);
 	if (!head)
 		die(_("Failed to resolve HEAD as a valid ref."));
 	if (!strcmp(head, "HEAD"))
@@ -749,7 +660,7 @@
 		if (!sorting)
 			sorting = ref_default_sorting();
 		sorting->ignore_case = icase;
-		print_ref_list(&filter, sorting);
+		print_ref_list(&filter, sorting, format);
 		print_columns(&output, colopts, NULL);
 		string_list_clear(&output, 0);
 		return 0;
diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 30383e9..8b85cb8 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -409,20 +409,20 @@
 	return 0;
 }
 
-static int batch_loose_object(const unsigned char *sha1,
+static int batch_loose_object(const struct object_id *oid,
 			      const char *path,
 			      void *data)
 {
-	sha1_array_append(data, sha1);
+	sha1_array_append(data, oid->hash);
 	return 0;
 }
 
-static int batch_packed_object(const unsigned char *sha1,
+static int batch_packed_object(const struct object_id *oid,
 			       struct packed_git *pack,
 			       uint32_t pos,
 			       void *data)
 {
-	sha1_array_append(data, sha1);
+	sha1_array_append(data, oid->hash);
 	return 0;
 }
 
diff --git a/builtin/check-attr.c b/builtin/check-attr.c
index 53a5a18..4d01ca0 100644
--- a/builtin/check-attr.c
+++ b/builtin/check-attr.c
@@ -24,12 +24,13 @@
 	OPT_END()
 };
 
-static void output_attr(int cnt, struct git_attr_check *check,
-	const char *file)
+static void output_attr(struct attr_check *check, const char *file)
 {
 	int j;
+	int cnt = check->nr;
+
 	for (j = 0; j < cnt; j++) {
-		const char *value = check[j].value;
+		const char *value = check->items[j].value;
 
 		if (ATTR_TRUE(value))
 			value = "set";
@@ -42,35 +43,38 @@
 			printf("%s%c" /* path */
 			       "%s%c" /* attrname */
 			       "%s%c" /* attrvalue */,
-			       file, 0, git_attr_name(check[j].attr), 0, value, 0);
+			       file, 0,
+			       git_attr_name(check->items[j].attr), 0, value, 0);
 		} else {
 			quote_c_style(file, NULL, stdout, 0);
-			printf(": %s: %s\n", git_attr_name(check[j].attr), value);
+			printf(": %s: %s\n",
+			       git_attr_name(check->items[j].attr), value);
 		}
-
 	}
 }
 
-static void check_attr(const char *prefix, int cnt,
-	struct git_attr_check *check, const char *file)
+static void check_attr(const char *prefix,
+		       struct attr_check *check,
+		       int collect_all,
+		       const char *file)
 {
 	char *full_path =
 		prefix_path(prefix, prefix ? strlen(prefix) : 0, file);
-	if (check != NULL) {
-		if (git_check_attr(full_path, cnt, check))
-			die("git_check_attr died");
-		output_attr(cnt, check, file);
+
+	if (collect_all) {
+		git_all_attrs(full_path, check);
 	} else {
-		if (git_all_attrs(full_path, &cnt, &check))
-			die("git_all_attrs died");
-		output_attr(cnt, check, file);
-		free(check);
+		if (git_check_attr(full_path, check))
+			die("git_check_attr died");
 	}
+	output_attr(check, file);
+
 	free(full_path);
 }
 
-static void check_attr_stdin_paths(const char *prefix, int cnt,
-	struct git_attr_check *check)
+static void check_attr_stdin_paths(const char *prefix,
+				   struct attr_check *check,
+				   int collect_all)
 {
 	struct strbuf buf = STRBUF_INIT;
 	struct strbuf unquoted = STRBUF_INIT;
@@ -84,7 +88,7 @@
 				die("line is badly quoted");
 			strbuf_swap(&buf, &unquoted);
 		}
-		check_attr(prefix, cnt, check, buf.buf);
+		check_attr(prefix, check, collect_all, buf.buf);
 		maybe_flush_or_die(stdout, "attribute to stdout");
 	}
 	strbuf_release(&buf);
@@ -99,7 +103,7 @@
 
 int cmd_check_attr(int argc, const char **argv, const char *prefix)
 {
-	struct git_attr_check *check;
+	struct attr_check *check;
 	int cnt, i, doubledash, filei;
 
 	if (!is_bare_repository())
@@ -159,28 +163,26 @@
 			error_with_usage("No file specified");
 	}
 
-	if (all_attrs) {
-		check = NULL;
-	} else {
-		check = xcalloc(cnt, sizeof(*check));
+	check = attr_check_alloc();
+	if (!all_attrs) {
 		for (i = 0; i < cnt; i++) {
-			const char *name;
-			struct git_attr *a;
-			name = argv[i];
-			a = git_attr(name);
+			const struct git_attr *a = git_attr(argv[i]);
+
 			if (!a)
 				return error("%s: not a valid attribute name",
-					name);
-			check[i].attr = a;
+					     argv[i]);
+			attr_check_append(check, a);
 		}
 	}
 
 	if (stdin_paths)
-		check_attr_stdin_paths(prefix, cnt, check);
+		check_attr_stdin_paths(prefix, check, all_attrs);
 	else {
 		for (i = filei; i < argc; i++)
-			check_attr(prefix, cnt, check, argv[i]);
+			check_attr(prefix, check, all_attrs, argv[i]);
 		maybe_flush_or_die(stdout, "attribute to stdout");
 	}
+
+	attr_check_free(check);
 	return 0;
 }
diff --git a/builtin/checkout.c b/builtin/checkout.c
index f174f50..81f07c3 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -452,7 +452,7 @@
 {
 	struct strbuf buf = STRBUF_INIT;
 
-	strbuf_branchname(&buf, branch->name);
+	strbuf_branchname(&buf, branch->name, INTERPRET_BRANCH_LOCAL);
 	if (strcmp(buf.buf, branch->name))
 		branch->name = xstrdup(buf.buf);
 	strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
diff --git a/builtin/clean.c b/builtin/clean.c
index d6bc3aa..d861f83 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -174,8 +174,10 @@
 		/* an empty dir could be removed even if it is unreadble */
 		res = dry_run ? 0 : rmdir(path->buf);
 		if (res) {
+			int saved_errno = errno;
 			quote_path_relative(path->buf, prefix, &quoted);
-			warning(_(msg_warn_remove_failed), quoted.buf);
+			errno = saved_errno;
+			warning_errno(_(msg_warn_remove_failed), quoted.buf);
 			*dir_gone = 0;
 		}
 		return res;
@@ -208,8 +210,10 @@
 				quote_path_relative(path->buf, prefix, &quoted);
 				string_list_append(&dels, quoted.buf);
 			} else {
+				int saved_errno = errno;
 				quote_path_relative(path->buf, prefix, &quoted);
-				warning(_(msg_warn_remove_failed), quoted.buf);
+				errno = saved_errno;
+				warning_errno(_(msg_warn_remove_failed), quoted.buf);
 				*dir_gone = 0;
 				ret = 1;
 			}
@@ -230,8 +234,10 @@
 		if (!res)
 			*dir_gone = 1;
 		else {
+			int saved_errno = errno;
 			quote_path_relative(path->buf, prefix, &quoted);
-			warning(_(msg_warn_remove_failed), quoted.buf);
+			errno = saved_errno;
+			warning_errno(_(msg_warn_remove_failed), quoted.buf);
 			*dir_gone = 0;
 			ret = 1;
 		}
@@ -981,8 +987,10 @@
 		} else {
 			res = dry_run ? 0 : unlink(abs_path.buf);
 			if (res) {
+				int saved_errno = errno;
 				qname = quote_path_relative(item->string, NULL, &buf);
-				warning(_(msg_warn_remove_failed), qname);
+				errno = saved_errno;
+				warning_errno(_(msg_warn_remove_failed), qname);
 				errors++;
 			} else if (!quiet) {
 				qname = quote_path_relative(item->string, NULL, &buf);
diff --git a/builtin/clone.c b/builtin/clone.c
index 3f63edb..b4c929b 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -681,7 +681,7 @@
 
 static int checkout(int submodule_progress)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 	char *head;
 	struct lock_file *lock_file;
 	struct unpack_trees_options opts;
@@ -692,7 +692,7 @@
 	if (option_no_checkout)
 		return 0;
 
-	head = resolve_refdup("HEAD", RESOLVE_REF_READING, sha1, NULL);
+	head = resolve_refdup("HEAD", RESOLVE_REF_READING, oid.hash, NULL);
 	if (!head) {
 		warning(_("remote HEAD refers to nonexistent ref, "
 			  "unable to checkout.\n"));
@@ -700,7 +700,7 @@
 	}
 	if (!strcmp(head, "HEAD")) {
 		if (advice_detached_head)
-			detach_advice(sha1_to_hex(sha1));
+			detach_advice(oid_to_hex(&oid));
 	} else {
 		if (!starts_with(head, "refs/heads/"))
 			die(_("HEAD not found below refs/heads!"));
@@ -721,7 +721,7 @@
 	opts.src_index = &the_index;
 	opts.dst_index = &the_index;
 
-	tree = parse_tree_indirect(sha1);
+	tree = parse_tree_indirect(oid.hash);
 	parse_tree(tree);
 	init_tree_desc(&t, tree->buffer, tree->size);
 	if (unpack_trees(1, &t, &opts) < 0)
@@ -731,7 +731,7 @@
 		die(_("unable to write new index file"));
 
 	err |= run_hook_le(NULL, "post-checkout", sha1_to_hex(null_sha1),
-			   sha1_to_hex(sha1), "1", NULL);
+			   oid_to_hex(&oid), "1", NULL);
 
 	if (!err && option_recursive) {
 		struct argv_array args = ARGV_ARRAY_INIT;
diff --git a/builtin/commit.c b/builtin/commit.c
index 2de5f6c..4e288bc 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -496,7 +496,7 @@
 static int run_status(FILE *fp, const char *index_file, const char *prefix, int nowarn,
 		      struct wt_status *s)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 
 	if (s->relative_paths)
 		s->prefix = prefix;
@@ -509,9 +509,9 @@
 	s->index_file = index_file;
 	s->fp = fp;
 	s->nowarn = nowarn;
-	s->is_initial = get_sha1(s->reference, sha1) ? 1 : 0;
+	s->is_initial = get_sha1(s->reference, oid.hash) ? 1 : 0;
 	if (!s->is_initial)
-		hashcpy(s->sha1_commit, sha1);
+		hashcpy(s->sha1_commit, oid.hash);
 	s->status_format = status_format;
 	s->ignore_submodule_arg = ignore_submodule_arg;
 
@@ -885,7 +885,7 @@
 		commitable = run_status(s->fp, index_file, prefix, 1, s);
 		s->use_color = saved_color_setting;
 	} else {
-		unsigned char sha1[20];
+		struct object_id oid;
 		const char *parent = "HEAD";
 
 		if (!active_nr && read_cache() < 0)
@@ -894,7 +894,7 @@
 		if (amend)
 			parent = "HEAD^1";
 
-		if (get_sha1(parent, sha1)) {
+		if (get_sha1(parent, oid.hash)) {
 			int i, ita_nr = 0;
 
 			for (i = 0; i < active_nr; i++)
@@ -1332,7 +1332,7 @@
 {
 	static struct wt_status s;
 	int fd;
-	unsigned char sha1[20];
+	struct object_id oid;
 	static struct option builtin_status_options[] = {
 		OPT__VERBOSE(&verbose, N_("be verbose")),
 		OPT_SET_INT('s', "short", &status_format,
@@ -1382,9 +1382,9 @@
 
 	fd = hold_locked_index(&index_lock, 0);
 
-	s.is_initial = get_sha1(s.reference, sha1) ? 1 : 0;
+	s.is_initial = get_sha1(s.reference, oid.hash) ? 1 : 0;
 	if (!s.is_initial)
-		hashcpy(s.sha1_commit, sha1);
+		hashcpy(s.sha1_commit, oid.hash);
 
 	s.ignore_submodule_arg = ignore_submodule_arg;
 	s.status_format = status_format;
@@ -1418,19 +1418,19 @@
 
 }
 
-static void print_summary(const char *prefix, const unsigned char *sha1,
+static void print_summary(const char *prefix, const struct object_id *oid,
 			  int initial_commit)
 {
 	struct rev_info rev;
 	struct commit *commit;
 	struct strbuf format = STRBUF_INIT;
-	unsigned char junk_sha1[20];
+	struct object_id junk_oid;
 	const char *head;
 	struct pretty_print_context pctx = {0};
 	struct strbuf author_ident = STRBUF_INIT;
 	struct strbuf committer_ident = STRBUF_INIT;
 
-	commit = lookup_commit(sha1);
+	commit = lookup_commit(oid->hash);
 	if (!commit)
 		die(_("couldn't look up newly created commit"));
 	if (parse_commit(commit))
@@ -1477,7 +1477,7 @@
 	rev.diffopt.break_opt = 0;
 	diff_setup_done(&rev.diffopt);
 
-	head = resolve_ref_unsafe("HEAD", 0, junk_sha1, NULL);
+	head = resolve_ref_unsafe("HEAD", 0, junk_oid.hash, NULL);
 	if (!strcmp(head, "HEAD"))
 		head = _("detached HEAD");
 	else
@@ -1522,8 +1522,8 @@
 	return git_status_config(k, v, s);
 }
 
-static int run_rewrite_hook(const unsigned char *oldsha1,
-			    const unsigned char *newsha1)
+static int run_rewrite_hook(const struct object_id *oldoid,
+			    const struct object_id *newoid)
 {
 	struct child_process proc = CHILD_PROCESS_INIT;
 	const char *argv[3];
@@ -1544,7 +1544,7 @@
 	code = start_command(&proc);
 	if (code)
 		return code;
-	strbuf_addf(&sb, "%s %s\n", sha1_to_hex(oldsha1), sha1_to_hex(newsha1));
+	strbuf_addf(&sb, "%s %s\n", oid_to_hex(oldoid), oid_to_hex(newoid));
 	sigchain_push(SIGPIPE, SIG_IGN);
 	write_in_full(proc.in, sb.buf, sb.len);
 	close(proc.in);
@@ -1636,7 +1636,7 @@
 	struct strbuf author_ident = STRBUF_INIT;
 	const char *index_file, *reflog_msg;
 	char *nl;
-	unsigned char sha1[20];
+	struct object_id oid;
 	struct commit_list *parents = NULL;
 	struct stat statbuf;
 	struct commit *current_head = NULL;
@@ -1651,10 +1651,10 @@
 	status_format = STATUS_FORMAT_NONE; /* Ignore status.short */
 	s.colopts = 0;
 
-	if (get_sha1("HEAD", sha1))
+	if (get_sha1("HEAD", oid.hash))
 		current_head = NULL;
 	else {
-		current_head = lookup_commit_or_die(sha1, "HEAD");
+		current_head = lookup_commit_or_die(oid.hash, "HEAD");
 		if (parse_commit(current_head))
 			die(_("could not parse HEAD commit"));
 	}
@@ -1759,7 +1759,7 @@
 	}
 
 	if (commit_tree_extended(sb.buf, sb.len, active_cache_tree->sha1,
-			 parents, sha1, author_ident.buf, sign_commit, extra)) {
+			 parents, oid.hash, author_ident.buf, sign_commit, extra)) {
 		rollback_index_files();
 		die(_("failed to write commit object"));
 	}
@@ -1776,7 +1776,7 @@
 
 	transaction = ref_transaction_begin(&err);
 	if (!transaction ||
-	    ref_transaction_update(transaction, "HEAD", sha1,
+	    ref_transaction_update(transaction, "HEAD", oid.hash,
 				   current_head
 				   ? current_head->object.oid.hash : null_sha1,
 				   0, sb.buf, &err) ||
@@ -1805,13 +1805,13 @@
 		cfg = init_copy_notes_for_rewrite("amend");
 		if (cfg) {
 			/* we are amending, so current_head is not NULL */
-			copy_note_for_rewrite(cfg, current_head->object.oid.hash, sha1);
+			copy_note_for_rewrite(cfg, current_head->object.oid.hash, oid.hash);
 			finish_copy_notes_for_rewrite(cfg, "Notes added by 'git commit --amend'");
 		}
-		run_rewrite_hook(current_head->object.oid.hash, sha1);
+		run_rewrite_hook(&current_head->object.oid, &oid);
 	}
 	if (!quiet)
-		print_summary(prefix, sha1, !current_head);
+		print_summary(prefix, &oid, !current_head);
 
 	strbuf_release(&err);
 	return 0;
diff --git a/builtin/count-objects.c b/builtin/count-objects.c
index a04b4f2..acb0594 100644
--- a/builtin/count-objects.c
+++ b/builtin/count-objects.c
@@ -53,7 +53,7 @@
 		report_garbage(PACKDIR_FILE_GARBAGE, path);
 }
 
-static int count_loose(const unsigned char *sha1, const char *path, void *data)
+static int count_loose(const struct object_id *oid, const char *path, void *data)
 {
 	struct stat st;
 
@@ -62,7 +62,7 @@
 	else {
 		loose_size += on_disk_bytes(st);
 		loose++;
-		if (verbose && has_sha1_pack(sha1))
+		if (verbose && has_sha1_pack(oid->hash))
 			packed_loose++;
 	}
 	return 0;
diff --git a/builtin/describe.c b/builtin/describe.c
index 01490a1..76c1805 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -28,7 +28,8 @@
 static int max_candidates = 10;
 static struct hashmap names;
 static int have_util;
-static const char *pattern;
+static struct string_list patterns = STRING_LIST_INIT_NODUP;
+static struct string_list exclude_patterns = STRING_LIST_INIT_NODUP;
 static int always;
 static const char *dirty;
 
@@ -39,11 +40,11 @@
 
 struct commit_name {
 	struct hashmap_entry entry;
-	unsigned char peeled[20];
+	struct object_id peeled;
 	struct tag *tag;
 	unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
 	unsigned name_checked:1;
-	unsigned char sha1[20];
+	struct object_id oid;
 	char *path;
 };
 
@@ -54,17 +55,17 @@
 static int commit_name_cmp(const struct commit_name *cn1,
 		const struct commit_name *cn2, const void *peeled)
 {
-	return hashcmp(cn1->peeled, peeled ? peeled : cn2->peeled);
+	return oidcmp(&cn1->peeled, peeled ? peeled : &cn2->peeled);
 }
 
-static inline struct commit_name *find_commit_name(const unsigned char *peeled)
+static inline struct commit_name *find_commit_name(const struct object_id *peeled)
 {
-	return hashmap_get_from_hash(&names, sha1hash(peeled), peeled);
+	return hashmap_get_from_hash(&names, sha1hash(peeled->hash), peeled->hash);
 }
 
 static int replace_name(struct commit_name *e,
 			       int prio,
-			       const unsigned char *sha1,
+			       const struct object_id *oid,
 			       struct tag **tag)
 {
 	if (!e || e->prio < prio)
@@ -77,13 +78,13 @@
 		struct tag *t;
 
 		if (!e->tag) {
-			t = lookup_tag(e->sha1);
+			t = lookup_tag(e->oid.hash);
 			if (!t || parse_tag(t))
 				return 1;
 			e->tag = t;
 		}
 
-		t = lookup_tag(sha1);
+		t = lookup_tag(oid->hash);
 		if (!t || parse_tag(t))
 			return 0;
 		*tag = t;
@@ -96,24 +97,24 @@
 }
 
 static void add_to_known_names(const char *path,
-			       const unsigned char *peeled,
+			       const struct object_id *peeled,
 			       int prio,
-			       const unsigned char *sha1)
+			       const struct object_id *oid)
 {
 	struct commit_name *e = find_commit_name(peeled);
 	struct tag *tag = NULL;
-	if (replace_name(e, prio, sha1, &tag)) {
+	if (replace_name(e, prio, oid, &tag)) {
 		if (!e) {
 			e = xmalloc(sizeof(struct commit_name));
-			hashcpy(e->peeled, peeled);
-			hashmap_entry_init(e, sha1hash(peeled));
+			oidcpy(&e->peeled, peeled);
+			hashmap_entry_init(e, sha1hash(peeled->hash));
 			hashmap_add(&names, e);
 			e->path = NULL;
 		}
 		e->tag = tag;
 		e->prio = prio;
 		e->name_checked = 0;
-		hashcpy(e->sha1, sha1);
+		oidcpy(&e->oid, oid);
 		free(e->path);
 		e->path = xstrdup(path);
 	}
@@ -129,9 +130,40 @@
 	if (!all && !is_tag)
 		return 0;
 
-	/* Accept only tags that match the pattern, if given */
-	if (pattern && (!is_tag || wildmatch(pattern, path + 10, 0, NULL)))
-		return 0;
+	/*
+	 * If we're given exclude patterns, first exclude any tag which match
+	 * any of the exclude pattern.
+	 */
+	if (exclude_patterns.nr) {
+		struct string_list_item *item;
+
+		if (!is_tag)
+			return 0;
+
+		for_each_string_list_item(item, &exclude_patterns) {
+			if (!wildmatch(item->string, path + 10, 0, NULL))
+				return 0;
+		}
+	}
+
+	/*
+	 * If we're given patterns, accept only tags which match at least one
+	 * pattern.
+	 */
+	if (patterns.nr) {
+		struct string_list_item *item;
+
+		if (!is_tag)
+			return 0;
+
+		for_each_string_list_item(item, &patterns) {
+			if (!wildmatch(item->string, path + 10, 0, NULL))
+				break;
+
+			/* If we get here, no pattern matched. */
+			return 0;
+		}
+	}
 
 	/* Is it annotated? */
 	if (!peel_ref(path, peeled.hash)) {
@@ -154,7 +186,7 @@
 	else
 		prio = 0;
 
-	add_to_known_names(all ? path + 5 : path + 10, peeled.hash, prio, oid->hash);
+	add_to_known_names(all ? path + 5 : path + 10, &peeled, prio, oid);
 	return 0;
 }
 
@@ -212,7 +244,7 @@
 static void display_name(struct commit_name *n)
 {
 	if (n->prio == 2 && !n->tag) {
-		n->tag = lookup_tag(n->sha1);
+		n->tag = lookup_tag(n->oid.hash);
 		if (!n->tag || parse_tag(n->tag))
 			die(_("annotated tag %s not available"), n->path);
 	}
@@ -230,14 +262,14 @@
 		printf("%s", n->path);
 }
 
-static void show_suffix(int depth, const unsigned char *sha1)
+static void show_suffix(int depth, const struct object_id *oid)
 {
-	printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
+	printf("-%d-g%s", depth, find_unique_abbrev(oid->hash, abbrev));
 }
 
 static void describe(const char *arg, int last_one)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 	struct commit *cmit, *gave_up_on = NULL;
 	struct commit_list *list;
 	struct commit_name *n;
@@ -246,20 +278,20 @@
 	unsigned long seen_commits = 0;
 	unsigned int unannotated_cnt = 0;
 
-	if (get_sha1(arg, sha1))
+	if (get_oid(arg, &oid))
 		die(_("Not a valid object name %s"), arg);
-	cmit = lookup_commit_reference(sha1);
+	cmit = lookup_commit_reference(oid.hash);
 	if (!cmit)
 		die(_("%s is not a valid '%s' object"), arg, commit_type);
 
-	n = find_commit_name(cmit->object.oid.hash);
+	n = find_commit_name(&cmit->object.oid);
 	if (n && (tags || all || n->prio == 2)) {
 		/*
 		 * Exact match to an existing ref.
 		 */
 		display_name(n);
 		if (longformat)
-			show_suffix(0, n->tag ? n->tag->tagged->oid.hash : sha1);
+			show_suffix(0, n->tag ? &n->tag->tagged->oid : &oid);
 		if (dirty)
 			printf("%s", dirty);
 		printf("\n");
@@ -276,7 +308,7 @@
 		struct commit *c;
 		struct commit_name *n = hashmap_iter_first(&names, &iter);
 		for (; n; n = hashmap_iter_next(&iter)) {
-			c = lookup_commit_reference_gently(n->peeled, 1);
+			c = lookup_commit_reference_gently(n->peeled.hash, 1);
 			if (c)
 				c->util = n;
 		}
@@ -380,7 +412,7 @@
 
 	display_name(all_matches[0].name);
 	if (abbrev)
-		show_suffix(all_matches[0].depth, cmit->object.oid.hash);
+		show_suffix(all_matches[0].depth, &cmit->object.oid);
 	if (dirty)
 		printf("%s", dirty);
 	printf("\n");
@@ -404,8 +436,10 @@
 			    N_("only output exact matches"), 0),
 		OPT_INTEGER(0, "candidates", &max_candidates,
 			    N_("consider <n> most recent tags (default: 10)")),
-		OPT_STRING(0, "match",       &pattern, N_("pattern"),
+		OPT_STRING_LIST(0, "match", &patterns, N_("pattern"),
 			   N_("only consider tags matching <pattern>")),
+		OPT_STRING_LIST(0, "exclude", &exclude_patterns, N_("pattern"),
+			   N_("do not consider tags matching <pattern>")),
 		OPT_BOOL(0, "always",        &always,
 			N_("show abbreviated commit object as fallback")),
 		{OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
@@ -430,6 +464,7 @@
 		die(_("--long is incompatible with --abbrev=0"));
 
 	if (contains) {
+		struct string_list_item *item;
 		struct argv_array args;
 
 		argv_array_init(&args);
@@ -440,8 +475,10 @@
 			argv_array_push(&args, "--always");
 		if (!all) {
 			argv_array_push(&args, "--tags");
-			if (pattern)
-				argv_array_pushf(&args, "--refs=refs/tags/%s", pattern);
+			for_each_string_list_item(item, &patterns)
+				argv_array_pushf(&args, "--refs=refs/tags/%s", item->string);
+			for_each_string_list_item(item, &exclude_patterns)
+				argv_array_pushf(&args, "--exclude=refs/tags/%s", item->string);
 		}
 		if (argc)
 			argv_array_pushv(&args, argv);
diff --git a/builtin/diff-tree.c b/builtin/diff-tree.c
index 8ce0048..326f88b 100644
--- a/builtin/diff-tree.c
+++ b/builtin/diff-tree.c
@@ -7,46 +7,44 @@
 
 static struct rev_info log_tree_opt;
 
-static int diff_tree_commit_sha1(const unsigned char *sha1)
+static int diff_tree_commit_sha1(const struct object_id *oid)
 {
-	struct commit *commit = lookup_commit_reference(sha1);
+	struct commit *commit = lookup_commit_reference(oid->hash);
 	if (!commit)
 		return -1;
 	return log_tree_commit(&log_tree_opt, commit);
 }
 
 /* Diff one or more commits. */
-static int stdin_diff_commit(struct commit *commit, char *line, int len)
+static int stdin_diff_commit(struct commit *commit, const char *p)
 {
-	unsigned char sha1[20];
-	if (isspace(line[40]) && !get_sha1_hex(line+41, sha1)) {
-		/* Graft the fake parents locally to the commit */
-		int pos = 41;
-		struct commit_list **pptr;
+	struct object_id oid;
+	struct commit_list **pptr = NULL;
 
-		/* Free the real parent list */
-		free_commit_list(commit->parents);
-		commit->parents = NULL;
-		pptr = &(commit->parents);
-		while (line[pos] && !get_sha1_hex(line + pos, sha1)) {
-			struct commit *parent = lookup_commit(sha1);
-			if (parent) {
-				pptr = &commit_list_insert(parent, pptr)->next;
-			}
-			pos += 41;
+	/* Graft the fake parents locally to the commit */
+	while (isspace(*p++) && !parse_oid_hex(p, &oid, &p)) {
+		struct commit *parent = lookup_commit(oid.hash);
+		if (!pptr) {
+			/* Free the real parent list */
+			free_commit_list(commit->parents);
+			commit->parents = NULL;
+			pptr = &(commit->parents);
+		}
+		if (parent) {
+			pptr = &commit_list_insert(parent, pptr)->next;
 		}
 	}
 	return log_tree_commit(&log_tree_opt, commit);
 }
 
 /* Diff two trees. */
-static int stdin_diff_trees(struct tree *tree1, char *line, int len)
+static int stdin_diff_trees(struct tree *tree1, const char *p)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 	struct tree *tree2;
-	if (len != 82 || !isspace(line[40]) || get_sha1_hex(line + 41, sha1))
+	if (!isspace(*p++) || parse_oid_hex(p, &oid, &p) || *p)
 		return error("Need exactly two trees, separated by a space");
-	tree2 = lookup_tree(sha1);
+	tree2 = lookup_tree(oid.hash);
 	if (!tree2 || parse_tree(tree2))
 		return -1;
 	printf("%s %s\n", oid_to_hex(&tree1->object.oid),
@@ -60,23 +58,24 @@
 static int diff_tree_stdin(char *line)
 {
 	int len = strlen(line);
-	unsigned char sha1[20];
+	struct object_id oid;
 	struct object *obj;
+	const char *p;
 
 	if (!len || line[len-1] != '\n')
 		return -1;
 	line[len-1] = 0;
-	if (get_sha1_hex(line, sha1))
+	if (parse_oid_hex(line, &oid, &p))
 		return -1;
-	obj = parse_object(sha1);
+	obj = parse_object(oid.hash);
 	if (!obj)
 		return -1;
 	if (obj->type == OBJ_COMMIT)
-		return stdin_diff_commit((struct commit *)obj, line, len);
+		return stdin_diff_commit((struct commit *)obj, p);
 	if (obj->type == OBJ_TREE)
-		return stdin_diff_trees((struct tree *)obj, line, len);
+		return stdin_diff_trees((struct tree *)obj, p);
 	error("Object %s is a %s, not a commit or tree",
-	      sha1_to_hex(sha1), typename(obj->type));
+	      oid_to_hex(&oid), typename(obj->type));
 	return -1;
 }
 
@@ -141,7 +140,7 @@
 		break;
 	case 1:
 		tree1 = opt->pending.objects[0].item;
-		diff_tree_commit_sha1(tree1->oid.hash);
+		diff_tree_commit_sha1(&tree1->oid);
 		break;
 	case 2:
 		tree1 = opt->pending.objects[0].item;
@@ -164,9 +163,9 @@
 			opt->diffopt.setup |= (DIFF_SETUP_USE_SIZE_CACHE |
 					       DIFF_SETUP_USE_CACHE);
 		while (fgets(line, sizeof(line), stdin)) {
-			unsigned char sha1[20];
+			struct object_id oid;
 
-			if (get_sha1_hex(line, sha1)) {
+			if (get_oid_hex(line, &oid)) {
 				fputs(line, stdout);
 				fflush(stdout);
 			}
diff --git a/builtin/fast-export.c b/builtin/fast-export.c
index 1e815b5..e022063 100644
--- a/builtin/fast-export.c
+++ b/builtin/fast-export.c
@@ -212,7 +212,7 @@
 	return strbuf_detach(&out, NULL);
 }
 
-static void export_blob(const unsigned char *sha1)
+static void export_blob(const struct object_id *oid)
 {
 	unsigned long size;
 	enum object_type type;
@@ -223,34 +223,34 @@
 	if (no_data)
 		return;
 
-	if (is_null_sha1(sha1))
+	if (is_null_oid(oid))
 		return;
 
-	object = lookup_object(sha1);
+	object = lookup_object(oid->hash);
 	if (object && object->flags & SHOWN)
 		return;
 
 	if (anonymize) {
 		buf = anonymize_blob(&size);
-		object = (struct object *)lookup_blob(sha1);
+		object = (struct object *)lookup_blob(oid->hash);
 		eaten = 0;
 	} else {
-		buf = read_sha1_file(sha1, &type, &size);
+		buf = read_sha1_file(oid->hash, &type, &size);
 		if (!buf)
-			die ("Could not read blob %s", sha1_to_hex(sha1));
-		if (check_sha1_signature(sha1, buf, size, typename(type)) < 0)
-			die("sha1 mismatch in blob %s", sha1_to_hex(sha1));
-		object = parse_object_buffer(sha1, type, size, buf, &eaten);
+			die ("Could not read blob %s", oid_to_hex(oid));
+		if (check_sha1_signature(oid->hash, buf, size, typename(type)) < 0)
+			die("sha1 mismatch in blob %s", oid_to_hex(oid));
+		object = parse_object_buffer(oid->hash, type, size, buf, &eaten);
 	}
 
 	if (!object)
-		die("Could not read blob %s", sha1_to_hex(sha1));
+		die("Could not read blob %s", oid_to_hex(oid));
 
 	mark_next_object(object);
 
 	printf("blob\nmark :%"PRIu32"\ndata %lu\n", last_idnum, size);
 	if (size && fwrite(buf, size, 1, stdout) != 1)
-		die_errno ("Could not write blob '%s'", sha1_to_hex(sha1));
+		die_errno ("Could not write blob '%s'", oid_to_hex(oid));
 	printf("\n");
 
 	show_progress();
@@ -323,19 +323,19 @@
 	}
 }
 
-static void *generate_fake_sha1(const void *old, size_t *len)
+static void *generate_fake_oid(const void *old, size_t *len)
 {
 	static uint32_t counter = 1; /* avoid null sha1 */
-	unsigned char *out = xcalloc(20, 1);
-	put_be32(out + 16, counter++);
+	unsigned char *out = xcalloc(GIT_SHA1_RAWSZ, 1);
+	put_be32(out + GIT_SHA1_RAWSZ - 4, counter++);
 	return out;
 }
 
-static const unsigned char *anonymize_sha1(const unsigned char *sha1)
+static const unsigned char *anonymize_sha1(const struct object_id *oid)
 {
 	static struct hashmap sha1s;
-	size_t len = 20;
-	return anonymize_mem(&sha1s, generate_fake_sha1, sha1, &len);
+	size_t len = GIT_SHA1_RAWSZ;
+	return anonymize_mem(&sha1s, generate_fake_oid, oid, &len);
 }
 
 static void show_filemodify(struct diff_queue_struct *q,
@@ -383,7 +383,7 @@
 			if (no_data || S_ISGITLINK(spec->mode))
 				printf("M %06o %s ", spec->mode,
 				       sha1_to_hex(anonymize ?
-						   anonymize_sha1(spec->oid.hash) :
+						   anonymize_sha1(&spec->oid) :
 						   spec->oid.hash));
 			else {
 				struct object *object = lookup_object(spec->oid.hash);
@@ -572,7 +572,7 @@
 	/* Export the referenced blobs, and remember the marks. */
 	for (i = 0; i < diff_queued_diff.nr; i++)
 		if (!S_ISGITLINK(diff_queued_diff.queue[i]->two->mode))
-			export_blob(diff_queued_diff.queue[i]->two->oid.hash);
+			export_blob(&diff_queued_diff.queue[i]->two->oid);
 
 	refname = commit->util;
 	if (anonymize) {
@@ -797,14 +797,14 @@
 
 	for (i = 0; i < info->nr; i++) {
 		struct rev_cmdline_entry *e = info->rev + i;
-		unsigned char sha1[20];
+		struct object_id oid;
 		struct commit *commit;
 		char *full_name;
 
 		if (e->flags & UNINTERESTING)
 			continue;
 
-		if (dwim_ref(e->name, strlen(e->name), sha1, &full_name) != 1)
+		if (dwim_ref(e->name, strlen(e->name), oid.hash, &full_name) != 1)
 			continue;
 
 		if (refspecs) {
@@ -828,7 +828,7 @@
 		case OBJ_COMMIT:
 			break;
 		case OBJ_BLOB:
-			export_blob(commit->object.oid.hash);
+			export_blob(&commit->object.oid);
 			continue;
 		default: /* OBJ_TAG (nested tags) is already handled */
 			warning("Tag points to object of unexpected type %s, skipping.",
@@ -912,7 +912,7 @@
 	while (fgets(line, sizeof(line), f)) {
 		uint32_t mark;
 		char *line_end, *mark_end;
-		unsigned char sha1[20];
+		struct object_id oid;
 		struct object *object;
 		struct commit *commit;
 		enum object_type type;
@@ -924,28 +924,28 @@
 
 		mark = strtoumax(line + 1, &mark_end, 10);
 		if (!mark || mark_end == line + 1
-			|| *mark_end != ' ' || get_sha1_hex(mark_end + 1, sha1))
+			|| *mark_end != ' ' || get_oid_hex(mark_end + 1, &oid))
 			die("corrupt mark line: %s", line);
 
 		if (last_idnum < mark)
 			last_idnum = mark;
 
-		type = sha1_object_info(sha1, NULL);
+		type = sha1_object_info(oid.hash, NULL);
 		if (type < 0)
-			die("object not found: %s", sha1_to_hex(sha1));
+			die("object not found: %s", oid_to_hex(&oid));
 
 		if (type != OBJ_COMMIT)
 			/* only commits */
 			continue;
 
-		commit = lookup_commit(sha1);
+		commit = lookup_commit(oid.hash);
 		if (!commit)
-			die("not a commit? can't happen: %s", sha1_to_hex(sha1));
+			die("not a commit? can't happen: %s", oid_to_hex(&oid));
 
 		object = &commit->object;
 
 		if (object->flags & SHOWN)
-			error("Object %s already has a mark", sha1_to_hex(sha1));
+			error("Object %s already has a mark", oid_to_hex(&oid));
 
 		mark_object(object, mark);
 
diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
index cfe9e44..2a1c1c2 100644
--- a/builtin/fetch-pack.c
+++ b/builtin/fetch-pack.c
@@ -219,12 +219,7 @@
 	 * remote no-such-ref' would silently succeed without issuing
 	 * an error.
 	 */
-	for (i = 0; i < nr_sought; i++) {
-		if (!sought[i] || sought[i]->matched)
-			continue;
-		error("no such remote ref %s", sought[i]->name);
-		ret = 1;
-	}
+	ret |= report_unmatched_refs(sought, nr_sought);
 
 	while (ref) {
 		printf("%s %s\n",
diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
index efab62f..6faa3c0 100644
--- a/builtin/fmt-merge-msg.c
+++ b/builtin/fmt-merge-msg.c
@@ -41,7 +41,7 @@
 };
 
 struct origin_data {
-	unsigned char sha1[20];
+	struct object_id oid;
 	unsigned is_local_branch:1;
 };
 
@@ -59,8 +59,8 @@
 struct merge_parents {
 	int alloc, nr;
 	struct merge_parent {
-		unsigned char given[20];
-		unsigned char commit[20];
+		struct object_id given;
+		struct object_id commit;
 		unsigned char used;
 	} *item;
 };
@@ -70,14 +70,14 @@
  * hundreds of heads at a time anyway.
  */
 static struct merge_parent *find_merge_parent(struct merge_parents *table,
-					      unsigned char *given,
-					      unsigned char *commit)
+					      struct object_id *given,
+					      struct object_id *commit)
 {
 	int i;
 	for (i = 0; i < table->nr; i++) {
-		if (given && hashcmp(table->item[i].given, given))
+		if (given && oidcmp(&table->item[i].given, given))
 			continue;
-		if (commit && hashcmp(table->item[i].commit, commit))
+		if (commit && oidcmp(&table->item[i].commit, commit))
 			continue;
 		return &table->item[i];
 	}
@@ -85,14 +85,14 @@
 }
 
 static void add_merge_parent(struct merge_parents *table,
-			     unsigned char *given,
-			     unsigned char *commit)
+			     struct object_id *given,
+			     struct object_id *commit)
 {
 	if (table->nr && find_merge_parent(table, given, commit))
 		return;
 	ALLOC_GROW(table->item, table->nr + 1, table->alloc);
-	hashcpy(table->item[table->nr].given, given);
-	hashcpy(table->item[table->nr].commit, commit);
+	oidcpy(&table->item[table->nr].given, given);
+	oidcpy(&table->item[table->nr].commit, commit);
 	table->item[table->nr].used = 0;
 	table->nr++;
 }
@@ -106,30 +106,30 @@
 	struct src_data *src_data;
 	struct string_list_item *item;
 	int pulling_head = 0;
-	unsigned char sha1[20];
+	struct object_id oid;
 
-	if (len < 43 || line[40] != '\t')
+	if (len < GIT_SHA1_HEXSZ + 3 || line[GIT_SHA1_HEXSZ] != '\t')
 		return 1;
 
-	if (starts_with(line + 41, "not-for-merge"))
+	if (starts_with(line + GIT_SHA1_HEXSZ + 1, "not-for-merge"))
 		return 0;
 
-	if (line[41] != '\t')
+	if (line[GIT_SHA1_HEXSZ + 1] != '\t')
 		return 2;
 
-	i = get_sha1_hex(line, sha1);
+	i = get_oid_hex(line, &oid);
 	if (i)
 		return 3;
 
-	if (!find_merge_parent(merge_parents, sha1, NULL))
+	if (!find_merge_parent(merge_parents, &oid, NULL))
 		return 0; /* subsumed by other parents */
 
 	origin_data = xcalloc(1, sizeof(struct origin_data));
-	hashcpy(origin_data->sha1, sha1);
+	oidcpy(&origin_data->oid, &oid);
 
 	if (line[len - 1] == '\n')
 		line[len - 1] = 0;
-	line += 42;
+	line += GIT_SHA1_HEXSZ + 2;
 
 	/*
 	 * At this point, line points at the beginning of comment e.g.
@@ -338,10 +338,10 @@
 	struct string_list committers = STRING_LIST_INIT_DUP;
 	int flags = UNINTERESTING | TREESAME | SEEN | SHOWN | ADDED;
 	struct strbuf sb = STRBUF_INIT;
-	const unsigned char *sha1 = origin_data->sha1;
+	const struct object_id *oid = &origin_data->oid;
 	int limit = opts->shortlog_len;
 
-	branch = deref_tag(parse_object(sha1), sha1_to_hex(sha1), 40);
+	branch = deref_tag(parse_object(oid->hash), oid_to_hex(oid), GIT_SHA1_HEXSZ);
 	if (!branch || branch->type != OBJ_COMMIT)
 		return;
 
@@ -531,7 +531,7 @@
 }
 
 static void find_merge_parents(struct merge_parents *result,
-			       struct strbuf *in, unsigned char *head)
+			       struct strbuf *in, struct object_id *head)
 {
 	struct commit_list *parents;
 	struct commit *head_commit;
@@ -542,31 +542,31 @@
 		int len;
 		char *p = in->buf + pos;
 		char *newline = strchr(p, '\n');
-		unsigned char sha1[20];
+		struct object_id oid;
 		struct commit *parent;
 		struct object *obj;
 
 		len = newline ? newline - p : strlen(p);
 		pos += len + !!newline;
 
-		if (len < 43 ||
-		    get_sha1_hex(p, sha1) ||
-		    p[40] != '\t' ||
-		    p[41] != '\t')
+		if (len < GIT_SHA1_HEXSZ + 3 ||
+		    get_oid_hex(p, &oid) ||
+		    p[GIT_SHA1_HEXSZ] != '\t' ||
+		    p[GIT_SHA1_HEXSZ + 1] != '\t')
 			continue; /* skip not-for-merge */
 		/*
 		 * Do not use get_merge_parent() here; we do not have
 		 * "name" here and we do not want to contaminate its
 		 * util field yet.
 		 */
-		obj = parse_object(sha1);
+		obj = parse_object(oid.hash);
 		parent = (struct commit *)peel_to_type(NULL, 0, obj, OBJ_COMMIT);
 		if (!parent)
 			continue;
 		commit_list_insert(parent, &parents);
-		add_merge_parent(result, obj->oid.hash, parent->object.oid.hash);
+		add_merge_parent(result, &obj->oid, &parent->object.oid);
 	}
-	head_commit = lookup_commit(head);
+	head_commit = lookup_commit(head->hash);
 	if (head_commit)
 		commit_list_insert(head_commit, &parents);
 	parents = reduce_heads(parents);
@@ -574,7 +574,7 @@
 	while (parents) {
 		struct commit *cmit = pop_commit(&parents);
 		for (i = 0; i < result->nr; i++)
-			if (!hashcmp(result->item[i].commit, cmit->object.oid.hash))
+			if (!oidcmp(&result->item[i].commit, &cmit->object.oid))
 				result->item[i].used = 1;
 	}
 
@@ -592,7 +592,7 @@
 		  struct fmt_merge_msg_opts *opts)
 {
 	int i = 0, pos = 0;
-	unsigned char head_sha1[20];
+	struct object_id head_oid;
 	const char *current_branch;
 	void *current_branch_to_free;
 	struct merge_parents merge_parents;
@@ -601,13 +601,13 @@
 
 	/* get current branch */
 	current_branch = current_branch_to_free =
-		resolve_refdup("HEAD", RESOLVE_REF_READING, head_sha1, NULL);
+		resolve_refdup("HEAD", RESOLVE_REF_READING, head_oid.hash, NULL);
 	if (!current_branch)
 		die("No current branch");
 	if (starts_with(current_branch, "refs/heads/"))
 		current_branch += 11;
 
-	find_merge_parents(&merge_parents, in, head_sha1);
+	find_merge_parents(&merge_parents, in, &head_oid);
 
 	/* get a line */
 	while (pos < in->len) {
@@ -633,7 +633,7 @@
 		struct commit *head;
 		struct rev_info rev;
 
-		head = lookup_commit_or_die(head_sha1, "HEAD");
+		head = lookup_commit_or_die(head_oid.hash, "HEAD");
 		init_revisions(&rev, NULL);
 		rev.commit_format = CMIT_FMT_ONELINE;
 		rev.ignore_merges = 1;
diff --git a/builtin/fsck.c b/builtin/fsck.c
index 1a5cacc..f76e416 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -396,13 +396,13 @@
 
 static int default_refs;
 
-static void fsck_handle_reflog_sha1(const char *refname, unsigned char *sha1,
+static void fsck_handle_reflog_oid(const char *refname, struct object_id *oid,
 	unsigned long timestamp)
 {
 	struct object *obj;
 
-	if (!is_null_sha1(sha1)) {
-		obj = lookup_object(sha1);
+	if (!is_null_oid(oid)) {
+		obj = lookup_object(oid->hash);
 		if (obj && (obj->flags & HAS_OBJ)) {
 			if (timestamp && name_objects)
 				add_decoration(fsck_walk_options.object_names,
@@ -411,13 +411,13 @@
 			obj->used = 1;
 			mark_object_reachable(obj);
 		} else {
-			error("%s: invalid reflog entry %s", refname, sha1_to_hex(sha1));
+			error("%s: invalid reflog entry %s", refname, oid_to_hex(oid));
 			errors_found |= ERROR_REACHABLE;
 		}
 	}
 }
 
-static int fsck_handle_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+static int fsck_handle_reflog_ent(struct object_id *ooid, struct object_id *noid,
 		const char *email, unsigned long timestamp, int tz,
 		const char *message, void *cb_data)
 {
@@ -425,10 +425,10 @@
 
 	if (verbose)
 		fprintf(stderr, "Checking reflog %s->%s\n",
-			sha1_to_hex(osha1), sha1_to_hex(nsha1));
+			oid_to_hex(ooid), oid_to_hex(noid));
 
-	fsck_handle_reflog_sha1(refname, osha1, 0);
-	fsck_handle_reflog_sha1(refname, nsha1, timestamp);
+	fsck_handle_reflog_oid(refname, ooid, 0);
+	fsck_handle_reflog_oid(refname, noid, timestamp);
 	return 0;
 }
 
@@ -491,7 +491,7 @@
 	}
 }
 
-static struct object *parse_loose_object(const unsigned char *sha1,
+static struct object *parse_loose_object(const struct object_id *oid,
 					 const char *path)
 {
 	struct object *obj;
@@ -500,27 +500,27 @@
 	unsigned long size;
 	int eaten;
 
-	if (read_loose_object(path, sha1, &type, &size, &contents) < 0)
+	if (read_loose_object(path, oid->hash, &type, &size, &contents) < 0)
 		return NULL;
 
 	if (!contents && type != OBJ_BLOB)
 		die("BUG: read_loose_object streamed a non-blob");
 
-	obj = parse_object_buffer(sha1, type, size, contents, &eaten);
+	obj = parse_object_buffer(oid->hash, type, size, contents, &eaten);
 
 	if (!eaten)
 		free(contents);
 	return obj;
 }
 
-static int fsck_loose(const unsigned char *sha1, const char *path, void *data)
+static int fsck_loose(const struct object_id *oid, const char *path, void *data)
 {
-	struct object *obj = parse_loose_object(sha1, path);
+	struct object *obj = parse_loose_object(oid, path);
 
 	if (!obj) {
 		errors_found |= ERROR_OBJECT;
 		error("%s: object corrupt or missing: %s",
-		      sha1_to_hex(sha1), path);
+		      oid_to_hex(oid), path);
 		return 0; /* keep checking other objects */
 	}
 
@@ -619,26 +619,26 @@
 	return err;
 }
 
-static void mark_object_for_connectivity(const unsigned char *sha1)
+static void mark_object_for_connectivity(const struct object_id *oid)
 {
-	struct object *obj = lookup_unknown_object(sha1);
+	struct object *obj = lookup_unknown_object(oid->hash);
 	obj->flags |= HAS_OBJ;
 }
 
-static int mark_loose_for_connectivity(const unsigned char *sha1,
+static int mark_loose_for_connectivity(const struct object_id *oid,
 				       const char *path,
 				       void *data)
 {
-	mark_object_for_connectivity(sha1);
+	mark_object_for_connectivity(oid);
 	return 0;
 }
 
-static int mark_packed_for_connectivity(const unsigned char *sha1,
+static int mark_packed_for_connectivity(const struct object_id *oid,
 					struct packed_git *pack,
 					uint32_t pos,
 					void *data)
 {
-	mark_object_for_connectivity(sha1);
+	mark_object_for_connectivity(oid);
 	return 0;
 }
 
diff --git a/builtin/gc.c b/builtin/gc.c
index 331f219..c2c61a5 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -33,6 +33,8 @@
 static int gc_auto_threshold = 6700;
 static int gc_auto_pack_limit = 50;
 static int detach_auto = 1;
+static unsigned long gc_log_expire_time;
+static const char *gc_log_expire = "1.day.ago";
 static const char *prune_expire = "2.weeks.ago";
 static const char *prune_worktrees_expire = "3.months.ago";
 
@@ -62,24 +64,31 @@
 		string_list_append(&pack_garbage, path);
 }
 
-static void git_config_date_string(const char *key, const char **output)
-{
-	if (git_config_get_string_const(key, output))
-		return;
-	if (strcmp(*output, "now")) {
-		unsigned long now = approxidate("now");
-		if (approxidate(*output) >= now)
-			git_die_config(key, _("Invalid %s: '%s'"), key, *output);
-	}
-}
-
 static void process_log_file(void)
 {
 	struct stat st;
-	if (!fstat(get_lock_file_fd(&log_lock), &st) && st.st_size)
+	if (fstat(get_lock_file_fd(&log_lock), &st)) {
+		/*
+		 * Perhaps there was an i/o error or another
+		 * unlikely situation.  Try to make a note of
+		 * this in gc.log along with any existing
+		 * messages.
+		 */
+		int saved_errno = errno;
+		fprintf(stderr, _("Failed to fstat %s: %s"),
+			get_tempfile_path(&log_lock.tempfile),
+			strerror(saved_errno));
+		fflush(stderr);
 		commit_lock_file(&log_lock);
-	else
+		errno = saved_errno;
+	} else if (st.st_size) {
+		/* There was some error recorded in the lock file */
+		commit_lock_file(&log_lock);
+	} else {
+		/* No error, clean up any old gc.log */
+		unlink(git_path("gc.log"));
 		rollback_lock_file(&log_lock);
+	}
 }
 
 static void process_log_file_at_exit(void)
@@ -111,8 +120,10 @@
 	git_config_get_int("gc.auto", &gc_auto_threshold);
 	git_config_get_int("gc.autopacklimit", &gc_auto_pack_limit);
 	git_config_get_bool("gc.autodetach", &detach_auto);
-	git_config_date_string("gc.pruneexpire", &prune_expire);
-	git_config_date_string("gc.worktreepruneexpire", &prune_worktrees_expire);
+	git_config_get_expiry("gc.pruneexpire", &prune_expire);
+	git_config_get_expiry("gc.worktreepruneexpire", &prune_worktrees_expire);
+	git_config_get_expiry("gc.logexpiry", &gc_log_expire);
+
 	git_config(git_default_config, NULL);
 }
 
@@ -290,19 +301,34 @@
 static int report_last_gc_error(void)
 {
 	struct strbuf sb = STRBUF_INIT;
-	int ret;
+	int ret = 0;
+	struct stat st;
+	char *gc_log_path = git_pathdup("gc.log");
 
-	ret = strbuf_read_file(&sb, git_path("gc.log"), 0);
+	if (stat(gc_log_path, &st)) {
+		if (errno == ENOENT)
+			goto done;
+
+		ret = error_errno(_("Can't stat %s"), gc_log_path);
+		goto done;
+	}
+
+	if (st.st_mtime < gc_log_expire_time)
+		goto done;
+
+	ret = strbuf_read_file(&sb, gc_log_path, 0);
 	if (ret > 0)
-		return error(_("The last gc run reported the following. "
+		ret = error(_("The last gc run reported the following. "
 			       "Please correct the root cause\n"
 			       "and remove %s.\n"
 			       "Automatic cleanup will not be performed "
 			       "until the file is removed.\n\n"
 			       "%s"),
-			     git_path("gc.log"), sb.buf);
+			    gc_log_path, sb.buf);
 	strbuf_release(&sb);
-	return 0;
+done:
+	free(gc_log_path);
+	return ret;
 }
 
 static int gc_before_repack(void)
@@ -349,7 +375,10 @@
 	argv_array_pushl(&prune_worktrees, "worktree", "prune", "--expire", NULL);
 	argv_array_pushl(&rerere, "rerere", "gc", NULL);
 
+	/* default expiry time, overwritten in gc_config */
 	gc_config();
+	if (parse_expiry_date(gc_log_expire, &gc_log_expire_time))
+		die(_("Failed to parse gc.logexpiry value %s"), gc_log_expire);
 
 	if (pack_refs < 0)
 		pack_refs = !is_bare_repository();
@@ -448,5 +477,8 @@
 		warning(_("There are too many unreachable loose objects; "
 			"run 'git prune' to remove them."));
 
+	if (!daemonized)
+		unlink(git_path("gc.log"));
+
 	return 0;
 }
diff --git a/builtin/grep.c b/builtin/grep.c
index 2c727ef..837836f 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -294,17 +294,17 @@
 	return st;
 }
 
-static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
+static void *lock_and_read_oid_file(const struct object_id *oid, enum object_type *type, unsigned long *size)
 {
 	void *data;
 
 	grep_read_lock();
-	data = read_sha1_file(sha1, type, size);
+	data = read_sha1_file(oid->hash, type, size);
 	grep_read_unlock();
 	return data;
 }
 
-static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
+static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
 		     const char *filename, int tree_name_len,
 		     const char *path)
 {
@@ -323,7 +323,7 @@
 
 #ifndef NO_PTHREADS
 	if (num_threads) {
-		add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, path, sha1);
+		add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, path, oid);
 		strbuf_release(&pathbuf);
 		return 0;
 	} else
@@ -332,7 +332,7 @@
 		struct grep_source gs;
 		int hit;
 
-		grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, path, sha1);
+		grep_source_init(&gs, GREP_SOURCE_SHA1, pathbuf.buf, path, oid);
 		strbuf_release(&pathbuf);
 		hit = grep_source(opt, &gs);
 
@@ -690,7 +690,7 @@
 			    ce_skip_worktree(ce)) {
 				if (ce_stage(ce) || ce_intent_to_add(ce))
 					continue;
-				hit |= grep_sha1(opt, ce->oid.hash, ce->name,
+				hit |= grep_oid(opt, &ce->oid, ce->name,
 						 0, ce->name);
 			} else {
 				hit |= grep_file(opt, ce->name);
@@ -750,7 +750,7 @@
 		strbuf_add(base, entry.path, te_len);
 
 		if (S_ISREG(entry.mode)) {
-			hit |= grep_sha1(opt, entry.oid->hash, base->buf, tn_len,
+			hit |= grep_oid(opt, entry.oid, base->buf, tn_len,
 					 check_attr ? base->buf + tn_len : NULL);
 		} else if (S_ISDIR(entry.mode)) {
 			enum object_type type;
@@ -758,7 +758,7 @@
 			void *data;
 			unsigned long size;
 
-			data = lock_and_read_sha1_file(entry.oid->hash, &type, &size);
+			data = lock_and_read_oid_file(entry.oid, &type, &size);
 			if (!data)
 				die(_("unable to read tree (%s)"),
 				    oid_to_hex(entry.oid));
@@ -787,7 +787,7 @@
 		       struct object *obj, const char *name, const char *path)
 {
 	if (obj->type == OBJ_BLOB)
-		return grep_sha1(opt, obj->oid.hash, name, 0, path);
+		return grep_oid(opt, &obj->oid, name, 0, path);
 	if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 		struct tree_desc tree;
 		void *data;
@@ -967,6 +967,7 @@
 	int dummy;
 	int use_index = 1;
 	int pattern_type_arg = GREP_PATTERN_TYPE_UNSPECIFIED;
+	int allow_revs;
 
 	struct option options[] = {
 		OPT_BOOL(0, "cached", &cached,
@@ -1149,26 +1150,69 @@
 
 	compile_grep_patterns(&opt);
 
-	/* Check revs and then paths */
+	/*
+	 * We have to find "--" in a separate pass, because its presence
+	 * influences how we will parse arguments that come before it.
+	 */
+	for (i = 0; i < argc; i++) {
+		if (!strcmp(argv[i], "--")) {
+			seen_dashdash = 1;
+			break;
+		}
+	}
+
+	/*
+	 * Resolve any rev arguments. If we have a dashdash, then everything up
+	 * to it must resolve as a rev. If not, then we stop at the first
+	 * non-rev and assume everything else is a path.
+	 */
+	allow_revs = use_index && !untracked;
 	for (i = 0; i < argc; i++) {
 		const char *arg = argv[i];
-		unsigned char sha1[20];
+		struct object_id oid;
 		struct object_context oc;
-		/* Is it a rev? */
-		if (!get_sha1_with_context(arg, 0, sha1, &oc)) {
-			struct object *object = parse_object_or_die(sha1, arg);
-			if (!seen_dashdash)
-				verify_non_filename(prefix, arg);
-			add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
-			continue;
-		}
+		struct object *object;
+
 		if (!strcmp(arg, "--")) {
 			i++;
-			seen_dashdash = 1;
+			break;
 		}
-		break;
+
+		if (!allow_revs) {
+			if (seen_dashdash)
+				die(_("--no-index or --untracked cannot be used with revs"));
+			break;
+		}
+
+		if (get_sha1_with_context(arg, 0, oid.hash, &oc)) {
+			if (seen_dashdash)
+				die(_("unable to resolve revision: %s"), arg);
+			break;
+		}
+
+		object = parse_object_or_die(oid.hash, arg);
+		if (!seen_dashdash)
+			verify_non_filename(prefix, arg);
+		add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
 	}
 
+	/*
+	 * Anything left over is presumed to be a path. But in the non-dashdash
+	 * "do what I mean" case, we verify and complain when that isn't true.
+	 */
+	if (!seen_dashdash) {
+		int j;
+		for (j = i; j < argc; j++)
+			verify_filename(prefix, argv[j], j == i && allow_revs);
+	}
+
+	parse_pathspec(&pathspec, 0,
+		       PATHSPEC_PREFER_CWD |
+		       (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
+		       prefix, argv + i);
+	pathspec.max_depth = opt.max_depth;
+	pathspec.recursive = 1;
+
 #ifndef NO_PTHREADS
 	if (list.nr || cached || show_in_pager)
 		num_threads = 0;
@@ -1190,20 +1234,6 @@
 	}
 #endif
 
-	/* The rest are paths */
-	if (!seen_dashdash) {
-		int j;
-		for (j = i; j < argc; j++)
-			verify_filename(prefix, argv[j], j == i);
-	}
-
-	parse_pathspec(&pathspec, 0,
-		       PATHSPEC_PREFER_CWD |
-		       (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
-		       prefix, argv + i);
-	pathspec.max_depth = opt.max_depth;
-	pathspec.recursive = 1;
-
 	if (recurse_submodules) {
 		gitmodules_config();
 		compile_submodule_options(&opt, &pathspec, cached, untracked,
@@ -1245,8 +1275,6 @@
 
 	if (!use_index || untracked) {
 		int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
-		if (list.nr)
-			die(_("--no-index or --untracked cannot be used with revs."));
 		hit = grep_directory(&opt, &pathspec, use_exclude, use_index);
 	} else if (0 <= opt_exclude) {
 		die(_("--[no-]exclude-standard cannot be used for tracked contents."));
diff --git a/builtin/init-db.c b/builtin/init-db.c
index 1d4d6a0..8a6acb0 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -338,7 +338,7 @@
 {
 	int reinit;
 	int exist_ok = flags & INIT_DB_EXIST_OK;
-	char *original_git_dir = real_pathdup(git_dir);
+	char *original_git_dir = real_pathdup(git_dir, 1);
 
 	if (real_git_dir) {
 		struct stat st;
@@ -489,7 +489,7 @@
 	argc = parse_options(argc, argv, prefix, init_db_options, init_db_usage, 0);
 
 	if (real_git_dir && !is_absolute_path(real_git_dir))
-		real_git_dir = real_pathdup(real_git_dir);
+		real_git_dir = real_pathdup(real_git_dir, 1);
 
 	if (argc == 1) {
 		int mkdir_tried = 0;
@@ -560,7 +560,7 @@
 		const char *git_dir_parent = strrchr(git_dir, '/');
 		if (git_dir_parent) {
 			char *rel = xstrndup(git_dir, git_dir_parent - git_dir);
-			git_work_tree_cfg = real_pathdup(rel);
+			git_work_tree_cfg = real_pathdup(rel, 1);
 			free(rel);
 		}
 		if (!git_work_tree_cfg)
diff --git a/builtin/log.c b/builtin/log.c
index 55d20cc..281af8c 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -989,8 +989,7 @@
 	    open_next_file(NULL, rev->numbered_files ? NULL : "cover-letter", rev, quiet))
 		return;
 
-	log_write_email_headers(rev, head, &pp.subject, &pp.after_subject,
-				&need_8bit_cte);
+	log_write_email_headers(rev, head, &pp.after_subject, &need_8bit_cte);
 
 	for (i = 0; !need_8bit_cte && i < nr; i++) {
 		const char *buf = get_commit_buffer(list[i], NULL);
@@ -1005,6 +1004,8 @@
 	msg = body;
 	pp.fmt = CMIT_FMT_EMAIL;
 	pp.date_mode.type = DATE_RFC2822;
+	pp.rev = rev;
+	pp.print_email_subject = 1;
 	pp_user_info(&pp, NULL, &sb, committer, encoding);
 	pp_title_line(&pp, &msg, &sb, encoding, need_8bit_cte);
 	pp_remainder(&pp, &msg, &sb, 0);
diff --git a/builtin/merge-base.c b/builtin/merge-base.c
index b572a37..cfe2a79 100644
--- a/builtin/merge-base.c
+++ b/builtin/merge-base.c
@@ -36,12 +36,12 @@
 
 static struct commit *get_commit_reference(const char *arg)
 {
-	unsigned char revkey[20];
+	struct object_id revkey;
 	struct commit *r;
 
-	if (get_sha1(arg, revkey))
+	if (get_oid(arg, &revkey))
 		die("Not a valid object name %s", arg);
-	r = lookup_commit_reference(revkey);
+	r = lookup_commit_reference(revkey.hash);
 	if (!r)
 		die("Not a valid commit name %s", arg);
 
@@ -113,14 +113,14 @@
 	unsigned int initial : 1;
 };
 
-static void add_one_commit(unsigned char *sha1, struct rev_collect *revs)
+static void add_one_commit(struct object_id *oid, struct rev_collect *revs)
 {
 	struct commit *commit;
 
-	if (is_null_sha1(sha1))
+	if (is_null_oid(oid))
 		return;
 
-	commit = lookup_commit(sha1);
+	commit = lookup_commit(oid->hash);
 	if (!commit ||
 	    (commit->object.flags & TMP_MARK) ||
 	    parse_commit(commit))
@@ -131,7 +131,7 @@
 	commit->object.flags |= TMP_MARK;
 }
 
-static int collect_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+static int collect_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
 				  const char *ident, unsigned long timestamp,
 				  int tz, const char *message, void *cbdata)
 {
@@ -139,15 +139,15 @@
 
 	if (revs->initial) {
 		revs->initial = 0;
-		add_one_commit(osha1, revs);
+		add_one_commit(ooid, revs);
 	}
-	add_one_commit(nsha1, revs);
+	add_one_commit(noid, revs);
 	return 0;
 }
 
 static int handle_fork_point(int argc, const char **argv)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 	char *refname;
 	const char *commitname;
 	struct rev_collect revs;
@@ -155,7 +155,7 @@
 	struct commit_list *bases;
 	int i, ret = 0;
 
-	switch (dwim_ref(argv[0], strlen(argv[0]), sha1, &refname)) {
+	switch (dwim_ref(argv[0], strlen(argv[0]), oid.hash, &refname)) {
 	case 0:
 		die("No such ref: '%s'", argv[0]);
 	case 1:
@@ -165,16 +165,16 @@
 	}
 
 	commitname = (argc == 2) ? argv[1] : "HEAD";
-	if (get_sha1(commitname, sha1))
+	if (get_oid(commitname, &oid))
 		die("Not a valid object name: '%s'", commitname);
 
-	derived = lookup_commit_reference(sha1);
+	derived = lookup_commit_reference(oid.hash);
 	memset(&revs, 0, sizeof(revs));
 	revs.initial = 1;
 	for_each_reflog_ent(refname, collect_one_reflog_ent, &revs);
 
-	if (!revs.nr && !get_sha1(refname, sha1))
-		add_one_commit(sha1, &revs);
+	if (!revs.nr && !get_oid(refname, &oid))
+		add_one_commit(&oid, &revs);
 
 	for (i = 0; i < revs.nr; i++)
 		revs.commit[i]->object.flags &= ~TMP_MARK;
diff --git a/builtin/merge.c b/builtin/merge.c
index a96d4fb..7554b8d 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -244,7 +244,7 @@
 	unlink(git_path_merge_mode());
 }
 
-static int save_state(unsigned char *stash)
+static int save_state(struct object_id *stash)
 {
 	int len;
 	struct child_process cp = CHILD_PROCESS_INIT;
@@ -265,7 +265,7 @@
 	else if (!len)		/* no changes */
 		return -1;
 	strbuf_setlen(&buffer, buffer.len-1);
-	if (get_sha1(buffer.buf, stash))
+	if (get_oid(buffer.buf, stash))
 		die(_("not a valid object: %s"), buffer.buf);
 	return 0;
 }
@@ -305,18 +305,18 @@
 		die(_("read-tree failed"));
 }
 
-static void restore_state(const unsigned char *head,
-			  const unsigned char *stash)
+static void restore_state(const struct object_id *head,
+			  const struct object_id *stash)
 {
 	struct strbuf sb = STRBUF_INIT;
 	const char *args[] = { "stash", "apply", NULL, NULL };
 
-	if (is_null_sha1(stash))
+	if (is_null_oid(stash))
 		return;
 
-	reset_hard(head, 1);
+	reset_hard(head->hash, 1);
 
-	args[2] = sha1_to_hex(stash);
+	args[2] = oid_to_hex(stash);
 
 	/*
 	 * It is OK to ignore error here, for example when there was
@@ -376,10 +376,10 @@
 
 static void finish(struct commit *head_commit,
 		   struct commit_list *remoteheads,
-		   const unsigned char *new_head, const char *msg)
+		   const struct object_id *new_head, const char *msg)
 {
 	struct strbuf reflog_message = STRBUF_INIT;
-	const unsigned char *head = head_commit->object.oid.hash;
+	const struct object_id *head = &head_commit->object.oid;
 
 	if (!msg)
 		strbuf_addstr(&reflog_message, getenv("GIT_REFLOG_ACTION"));
@@ -397,7 +397,7 @@
 		else {
 			const char *argv_gc_auto[] = { "gc", "--auto", NULL };
 			update_ref(reflog_message.buf, "HEAD",
-				new_head, head, 0,
+				new_head->hash, head->hash, 0,
 				UPDATE_REFS_DIE_ON_ERR);
 			/*
 			 * We ignore errors in 'gc --auto', since the
@@ -416,7 +416,7 @@
 			DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
 		opts.detect_rename = DIFF_DETECT_RENAME;
 		diff_setup_done(&opts);
-		diff_tree_sha1(head, new_head, "", &opts);
+		diff_tree_sha1(head->hash, new_head->hash, "", &opts);
 		diffcore_std(&opts);
 		diff_flush(&opts);
 	}
@@ -431,35 +431,35 @@
 static void merge_name(const char *remote, struct strbuf *msg)
 {
 	struct commit *remote_head;
-	unsigned char branch_head[20];
+	struct object_id branch_head;
 	struct strbuf buf = STRBUF_INIT;
 	struct strbuf bname = STRBUF_INIT;
 	const char *ptr;
 	char *found_ref;
 	int len, early;
 
-	strbuf_branchname(&bname, remote);
+	strbuf_branchname(&bname, remote, 0);
 	remote = bname.buf;
 
-	memset(branch_head, 0, sizeof(branch_head));
+	oidclr(&branch_head);
 	remote_head = get_merge_parent(remote);
 	if (!remote_head)
 		die(_("'%s' does not point to a commit"), remote);
 
-	if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
+	if (dwim_ref(remote, strlen(remote), branch_head.hash, &found_ref) > 0) {
 		if (starts_with(found_ref, "refs/heads/")) {
 			strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
-				    sha1_to_hex(branch_head), remote);
+				    oid_to_hex(&branch_head), remote);
 			goto cleanup;
 		}
 		if (starts_with(found_ref, "refs/tags/")) {
 			strbuf_addf(msg, "%s\t\ttag '%s' of .\n",
-				    sha1_to_hex(branch_head), remote);
+				    oid_to_hex(&branch_head), remote);
 			goto cleanup;
 		}
 		if (starts_with(found_ref, "refs/remotes/")) {
 			strbuf_addf(msg, "%s\t\tremote-tracking branch '%s' of .\n",
-				    sha1_to_hex(branch_head), remote);
+				    oid_to_hex(&branch_head), remote);
 			goto cleanup;
 		}
 	}
@@ -590,8 +590,8 @@
 	return git_diff_ui_config(k, v, cb);
 }
 
-static int read_tree_trivial(unsigned char *common, unsigned char *head,
-			     unsigned char *one)
+static int read_tree_trivial(struct object_id *common, struct object_id *head,
+			     struct object_id *one)
 {
 	int i, nr_trees = 0;
 	struct tree *trees[MAX_UNPACK_TREES];
@@ -606,13 +606,13 @@
 	opts.verbose_update = 1;
 	opts.trivial_merges_only = 1;
 	opts.merge = 1;
-	trees[nr_trees] = parse_tree_indirect(common);
+	trees[nr_trees] = parse_tree_indirect(common->hash);
 	if (!trees[nr_trees++])
 		return -1;
-	trees[nr_trees] = parse_tree_indirect(head);
+	trees[nr_trees] = parse_tree_indirect(head->hash);
 	if (!trees[nr_trees++])
 		return -1;
-	trees[nr_trees] = parse_tree_indirect(one);
+	trees[nr_trees] = parse_tree_indirect(one->hash);
 	if (!trees[nr_trees++])
 		return -1;
 	opts.fn = threeway_merge;
@@ -626,9 +626,9 @@
 	return 0;
 }
 
-static void write_tree_trivial(unsigned char *sha1)
+static void write_tree_trivial(struct object_id *oid)
 {
-	if (write_cache_as_tree(sha1, 0, NULL))
+	if (write_cache_as_tree(oid->hash, 0, NULL))
 		die(_("git write-tree failed to write a tree"));
 }
 
@@ -781,7 +781,7 @@
 
 static int merge_trivial(struct commit *head, struct commit_list *remoteheads)
 {
-	unsigned char result_tree[20], result_commit[20];
+	struct object_id result_tree, result_commit;
 	struct commit_list *parents, **pptr = &parents;
 	static struct lock_file lock;
 
@@ -792,15 +792,15 @@
 		return error(_("Unable to write index."));
 	rollback_lock_file(&lock);
 
-	write_tree_trivial(result_tree);
+	write_tree_trivial(&result_tree);
 	printf(_("Wonderful.\n"));
 	pptr = commit_list_append(head, pptr);
 	pptr = commit_list_append(remoteheads->item, pptr);
 	prepare_to_commit(remoteheads);
-	if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
-			result_commit, NULL, sign_commit))
+	if (commit_tree(merge_msg.buf, merge_msg.len, result_tree.hash, parents,
+			result_commit.hash, NULL, sign_commit))
 		die(_("failed to write commit object"));
-	finish(head, remoteheads, result_commit, "In-index merge");
+	finish(head, remoteheads, &result_commit, "In-index merge");
 	drop_save();
 	return 0;
 }
@@ -809,12 +809,12 @@
 			    int head_subsumed,
 			    struct commit_list *common,
 			    struct commit_list *remoteheads,
-			    unsigned char *result_tree,
+			    struct object_id *result_tree,
 			    const char *wt_strategy)
 {
 	struct commit_list *parents = NULL;
 	struct strbuf buf = STRBUF_INIT;
-	unsigned char result_commit[20];
+	struct object_id result_commit;
 
 	free_commit_list(common);
 	parents = remoteheads;
@@ -822,11 +822,11 @@
 		commit_list_insert(head, &parents);
 	strbuf_addch(&merge_msg, '\n');
 	prepare_to_commit(remoteheads);
-	if (commit_tree(merge_msg.buf, merge_msg.len, result_tree, parents,
-			result_commit, NULL, sign_commit))
+	if (commit_tree(merge_msg.buf, merge_msg.len, result_tree->hash, parents,
+			result_commit.hash, NULL, sign_commit))
 		die(_("failed to write commit object"));
 	strbuf_addf(&buf, "Merge made by the '%s' strategy.", wt_strategy);
-	finish(head, remoteheads, result_commit, buf.buf);
+	finish(head, remoteheads, &result_commit, buf.buf);
 	strbuf_release(&buf);
 	drop_save();
 	return 0;
@@ -854,18 +854,18 @@
 }
 
 static struct commit *is_old_style_invocation(int argc, const char **argv,
-					      const unsigned char *head)
+					      const struct object_id *head)
 {
 	struct commit *second_token = NULL;
 	if (argc > 2) {
-		unsigned char second_sha1[20];
+		struct object_id second_oid;
 
-		if (get_sha1(argv[1], second_sha1))
+		if (get_oid(argv[1], &second_oid))
 			return NULL;
-		second_token = lookup_commit_reference_gently(second_sha1, 0);
+		second_token = lookup_commit_reference_gently(second_oid.hash, 0);
 		if (!second_token)
 			die(_("'%s' is not a commit"), argv[1]);
-		if (hashcmp(second_token->object.oid.hash, head))
+		if (oidcmp(&second_token->object.oid, head))
 			return NULL;
 	}
 	return second_token;
@@ -1038,7 +1038,7 @@
 		die_errno(_("could not close '%s'"), filename);
 
 	for (pos = 0; pos < merge_names->len; pos = npos) {
-		unsigned char sha1[20];
+		struct object_id oid;
 		char *ptr;
 		struct commit *commit;
 
@@ -1048,16 +1048,16 @@
 		else
 			npos = merge_names->len;
 
-		if (npos - pos < 40 + 2 ||
-		    get_sha1_hex(merge_names->buf + pos, sha1))
+		if (npos - pos < GIT_SHA1_HEXSZ + 2 ||
+		    get_oid_hex(merge_names->buf + pos, &oid))
 			commit = NULL; /* bad */
-		else if (memcmp(merge_names->buf + pos + 40, "\t\t", 2))
+		else if (memcmp(merge_names->buf + pos + GIT_SHA1_HEXSZ, "\t\t", 2))
 			continue; /* not-for-merge */
 		else {
-			char saved = merge_names->buf[pos + 40];
-			merge_names->buf[pos + 40] = '\0';
+			char saved = merge_names->buf[pos + GIT_SHA1_HEXSZ];
+			merge_names->buf[pos + GIT_SHA1_HEXSZ] = '\0';
 			commit = get_merge_parent(merge_names->buf + pos);
-			merge_names->buf[pos + 40] = saved;
+			merge_names->buf[pos + GIT_SHA1_HEXSZ] = saved;
 		}
 		if (!commit) {
 			if (ptr)
@@ -1117,9 +1117,7 @@
 
 int cmd_merge(int argc, const char **argv, const char *prefix)
 {
-	unsigned char result_tree[20];
-	unsigned char stash[20];
-	unsigned char head_sha1[20];
+	struct object_id result_tree, stash, head_oid;
 	struct commit *head_commit;
 	struct strbuf buf = STRBUF_INIT;
 	const char *head_arg;
@@ -1138,13 +1136,13 @@
 	 * Check if we are _not_ on a detached HEAD, i.e. if there is a
 	 * current branch.
 	 */
-	branch = branch_to_free = resolve_refdup("HEAD", 0, head_sha1, NULL);
+	branch = branch_to_free = resolve_refdup("HEAD", 0, head_oid.hash, NULL);
 	if (branch && starts_with(branch, "refs/heads/"))
 		branch += 11;
-	if (!branch || is_null_sha1(head_sha1))
+	if (!branch || is_null_oid(&head_oid))
 		head_commit = NULL;
 	else
-		head_commit = lookup_commit_or_die(head_sha1, "HEAD");
+		head_commit = lookup_commit_or_die(head_oid.hash, "HEAD");
 
 	init_diff_ui_defaults();
 	git_config(git_merge_config, NULL);
@@ -1242,7 +1240,7 @@
 		 * to forbid "git merge" into a branch yet to be born.
 		 * We do the same for "git pull".
 		 */
-		unsigned char *remote_head_sha1;
+		struct object_id *remote_head_oid;
 		if (squash)
 			die(_("Squash commit into empty head not supported yet"));
 		if (fast_forward == FF_NO)
@@ -1254,9 +1252,9 @@
 			die(_("%s - not something we can merge"), argv[0]);
 		if (remoteheads->next)
 			die(_("Can merge only exactly one commit into empty head"));
-		remote_head_sha1 = remoteheads->item->object.oid.hash;
-		read_empty(remote_head_sha1, 0);
-		update_ref("initial pull", "HEAD", remote_head_sha1,
+		remote_head_oid = &remoteheads->item->object.oid;
+		read_empty(remote_head_oid->hash, 0);
+		update_ref("initial pull", "HEAD", remote_head_oid->hash,
 			   NULL, 0, UPDATE_REFS_DIE_ON_ERR);
 		goto done;
 	}
@@ -1270,7 +1268,7 @@
 	 * additional safety measure to check for it.
 	 */
 	if (!have_message &&
-	    is_old_style_invocation(argc, argv, head_commit->object.oid.hash)) {
+	    is_old_style_invocation(argc, argv, &head_commit->object.oid)) {
 		warning("old-style 'git merge <msg> HEAD <commit>' is deprecated.");
 		strbuf_addstr(&merge_msg, argv[0]);
 		head_arg = argv[1];
@@ -1422,7 +1420,7 @@
 			goto done;
 		}
 
-		finish(head_commit, remoteheads, commit->object.oid.hash, msg.buf);
+		finish(head_commit, remoteheads, &commit->object.oid, msg.buf);
 		drop_save();
 		goto done;
 	} else if (!remoteheads->next && common->next)
@@ -1441,9 +1439,9 @@
 			/* See if it is really trivial. */
 			git_committer_info(IDENT_STRICT);
 			printf(_("Trying really trivial in-index merge...\n"));
-			if (!read_tree_trivial(common->item->object.oid.hash,
-					       head_commit->object.oid.hash,
-					       remoteheads->item->object.oid.hash)) {
+			if (!read_tree_trivial(&common->item->object.oid,
+					       &head_commit->object.oid,
+					       &remoteheads->item->object.oid)) {
 				ret = merge_trivial(head_commit, remoteheads);
 				goto done;
 			}
@@ -1495,14 +1493,14 @@
 	    /*
 	     * Stash away the local changes so that we can try more than one.
 	     */
-	    save_state(stash))
-		hashclr(stash);
+	    save_state(&stash))
+		oidclr(&stash);
 
 	for (i = 0; i < use_strategies_nr; i++) {
 		int ret;
 		if (i) {
 			printf(_("Rewinding the tree to pristine...\n"));
-			restore_state(head_commit->object.oid.hash, stash);
+			restore_state(&head_commit->object.oid, &stash);
 		}
 		if (use_strategies_nr != 1)
 			printf(_("Trying merge strategy %s...\n"),
@@ -1547,7 +1545,7 @@
 		}
 
 		/* Automerge succeeded. */
-		write_tree_trivial(result_tree);
+		write_tree_trivial(&result_tree);
 		automerge_was_ok = 1;
 		break;
 	}
@@ -1559,7 +1557,7 @@
 	if (automerge_was_ok) {
 		ret = finish_automerge(head_commit, head_subsumed,
 				       common, remoteheads,
-				       result_tree, wt_strategy);
+				       &result_tree, wt_strategy);
 		goto done;
 	}
 
@@ -1568,7 +1566,7 @@
 	 * it up.
 	 */
 	if (!best_strategy) {
-		restore_state(head_commit->object.oid.hash, stash);
+		restore_state(&head_commit->object.oid, &stash);
 		if (use_strategies_nr > 1)
 			fprintf(stderr,
 				_("No merge strategy handled the merge.\n"));
@@ -1581,7 +1579,7 @@
 		; /* We already have its result in the working tree. */
 	else {
 		printf(_("Rewinding the tree to pristine...\n"));
-		restore_state(head_commit->object.oid.hash, stash);
+		restore_state(&head_commit->object.oid, &stash);
 		printf(_("Using the %s to prepare resolving by hand.\n"),
 			best_strategy);
 		try_merge_strategy(best_strategy, common, remoteheads,
diff --git a/builtin/name-rev.c b/builtin/name-rev.c
index cd89d48..8bdc3ea 100644
--- a/builtin/name-rev.c
+++ b/builtin/name-rev.c
@@ -108,7 +108,8 @@
 struct name_ref_data {
 	int tags_only;
 	int name_only;
-	const char *ref_filter;
+	struct string_list ref_filters;
+	struct string_list exclude_filters;
 };
 
 static struct tip_table {
@@ -150,18 +151,49 @@
 	if (data->tags_only && !starts_with(path, "refs/tags/"))
 		return 0;
 
-	if (data->ref_filter) {
-		switch (subpath_matches(path, data->ref_filter)) {
-		case -1: /* did not match */
-			return 0;
-		case 0:  /* matched fully */
-			break;
-		default: /* matched subpath */
-			can_abbreviate_output = 1;
-			break;
+	if (data->exclude_filters.nr) {
+		struct string_list_item *item;
+
+		for_each_string_list_item(item, &data->exclude_filters) {
+			if (subpath_matches(path, item->string) >= 0)
+				return 0;
 		}
 	}
 
+	if (data->ref_filters.nr) {
+		struct string_list_item *item;
+		int matched = 0;
+
+		/* See if any of the patterns match. */
+		for_each_string_list_item(item, &data->ref_filters) {
+			/*
+			 * Check all patterns even after finding a match, so
+			 * that we can see if a match with a subpath exists.
+			 * When a user asked for 'refs/tags/v*' and 'v1.*',
+			 * both of which match, the user is showing her
+			 * willingness to accept a shortened output by having
+			 * the 'v1.*' in the acceptable refnames, so we
+			 * shouldn't stop when seeing 'refs/tags/v1.4' matches
+			 * 'refs/tags/v*'.  We should show it as 'v1.4'.
+			 */
+			switch (subpath_matches(path, item->string)) {
+			case -1: /* did not match */
+				break;
+			case 0: /* matched fully */
+				matched = 1;
+				break;
+			default: /* matched subpath */
+				matched = 1;
+				can_abbreviate_output = 1;
+				break;
+			}
+		}
+
+		/* If none of the patterns matched, stop now */
+		if (!matched)
+			return 0;
+	}
+
 	add_to_tip_table(oid->hash, path, can_abbreviate_output);
 
 	while (o && o->type == OBJ_TAG) {
@@ -306,12 +338,14 @@
 {
 	struct object_array revs = OBJECT_ARRAY_INIT;
 	int all = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0;
-	struct name_ref_data data = { 0, 0, NULL };
+	struct name_ref_data data = { 0, 0, STRING_LIST_INIT_NODUP, STRING_LIST_INIT_NODUP };
 	struct option opts[] = {
 		OPT_BOOL(0, "name-only", &data.name_only, N_("print only names (no SHA-1)")),
 		OPT_BOOL(0, "tags", &data.tags_only, N_("only use tags to name the commits")),
-		OPT_STRING(0, "refs", &data.ref_filter, N_("pattern"),
+		OPT_STRING_LIST(0, "refs", &data.ref_filters, N_("pattern"),
 				   N_("only use refs matching <pattern>")),
+		OPT_STRING_LIST(0, "exclude", &data.exclude_filters, N_("pattern"),
+				   N_("ignore refs matching <pattern>")),
 		OPT_GROUP(""),
 		OPT_BOOL(0, "all", &all, N_("list all commits reachable from all refs")),
 		OPT_BOOL(0, "stdin", &transform_stdin, N_("read from stdin")),
diff --git a/builtin/notes.c b/builtin/notes.c
index 5248a9b..0513f74 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -681,9 +681,9 @@
 	 * notes_merge_abort() to remove .git/NOTES_MERGE_WORKTREE.
 	 */
 
-	if (delete_ref("NOTES_MERGE_PARTIAL", NULL, 0))
+	if (delete_ref(NULL, "NOTES_MERGE_PARTIAL", NULL, 0))
 		ret += error(_("failed to delete ref NOTES_MERGE_PARTIAL"));
-	if (delete_ref("NOTES_MERGE_REF", NULL, REF_NODEREF))
+	if (delete_ref(NULL, "NOTES_MERGE_REF", NULL, REF_NODEREF))
 		ret += error(_("failed to delete ref NOTES_MERGE_REF"));
 	if (notes_merge_abort(o))
 		ret += error(_("failed to remove 'git notes merge' worktree"));
@@ -693,7 +693,7 @@
 static int merge_commit(struct notes_merge_options *o)
 {
 	struct strbuf msg = STRBUF_INIT;
-	unsigned char sha1[20], parent_sha1[20];
+	struct object_id oid, parent_oid;
 	struct notes_tree *t;
 	struct commit *partial;
 	struct pretty_print_context pretty_ctx;
@@ -705,27 +705,27 @@
 	 * and target notes ref from .git/NOTES_MERGE_REF.
 	 */
 
-	if (get_sha1("NOTES_MERGE_PARTIAL", sha1))
+	if (get_oid("NOTES_MERGE_PARTIAL", &oid))
 		die(_("failed to read ref NOTES_MERGE_PARTIAL"));
-	else if (!(partial = lookup_commit_reference(sha1)))
+	else if (!(partial = lookup_commit_reference(oid.hash)))
 		die(_("could not find commit from NOTES_MERGE_PARTIAL."));
 	else if (parse_commit(partial))
 		die(_("could not parse commit from NOTES_MERGE_PARTIAL."));
 
 	if (partial->parents)
-		hashcpy(parent_sha1, partial->parents->item->object.oid.hash);
+		oidcpy(&parent_oid, &partial->parents->item->object.oid);
 	else
-		hashclr(parent_sha1);
+		oidclr(&parent_oid);
 
 	t = xcalloc(1, sizeof(struct notes_tree));
 	init_notes(t, "NOTES_MERGE_PARTIAL", combine_notes_overwrite, 0);
 
 	o->local_ref = local_ref_to_free =
-		resolve_refdup("NOTES_MERGE_REF", 0, sha1, NULL);
+		resolve_refdup("NOTES_MERGE_REF", 0, oid.hash, NULL);
 	if (!o->local_ref)
 		die(_("failed to resolve NOTES_MERGE_REF"));
 
-	if (notes_merge_commit(o, t, partial, sha1))
+	if (notes_merge_commit(o, t, partial, oid.hash))
 		die(_("failed to finalize notes merge"));
 
 	/* Reuse existing commit message in reflog message */
@@ -733,8 +733,8 @@
 	format_commit_message(partial, "%s", &msg, &pretty_ctx);
 	strbuf_trim(&msg);
 	strbuf_insert(&msg, 0, "notes: ", 7);
-	update_ref(msg.buf, o->local_ref, sha1,
-		   is_null_sha1(parent_sha1) ? NULL : parent_sha1,
+	update_ref(msg.buf, o->local_ref, oid.hash,
+		   is_null_oid(&parent_oid) ? NULL : parent_oid.hash,
 		   0, UPDATE_REFS_DIE_ON_ERR);
 
 	free_notes(t);
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 8841f8b..16517f2 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -894,24 +894,15 @@
 			written, nr_result);
 }
 
-static void setup_delta_attr_check(struct git_attr_check *check)
-{
-	static struct git_attr *attr_delta;
-
-	if (!attr_delta)
-		attr_delta = git_attr("delta");
-
-	check[0].attr = attr_delta;
-}
-
 static int no_try_delta(const char *path)
 {
-	struct git_attr_check check[1];
+	static struct attr_check *check;
 
-	setup_delta_attr_check(check);
-	if (git_check_attr(path, ARRAY_SIZE(check), check))
+	if (!check)
+		check = attr_check_initl("delta", NULL);
+	if (git_check_attr(path, check))
 		return 0;
-	if (ATTR_FALSE(check->value))
+	if (ATTR_FALSE(check->items[0].value))
 		return 1;
 	return 0;
 }
@@ -1539,6 +1530,8 @@
  *   2. Updating our size/type to the non-delta representation. These were
  *      either not recorded initially (size) or overwritten with the delta type
  *      (type) when check_object() decided to reuse the delta.
+ *
+ *   3. Resetting our delta depth, as we are now a base object.
  */
 static void drop_reused_delta(struct object_entry *entry)
 {
@@ -1552,6 +1545,7 @@
 			p = &(*p)->delta_sibling;
 	}
 	entry->delta = NULL;
+	entry->depth = 0;
 
 	oi.sizep = &entry->size;
 	oi.typep = &entry->type;
@@ -1570,39 +1564,123 @@
  * Follow the chain of deltas from this entry onward, throwing away any links
  * that cause us to hit a cycle (as determined by the DFS state flags in
  * the entries).
+ *
+ * We also detect too-long reused chains that would violate our --depth
+ * limit.
  */
 static void break_delta_chains(struct object_entry *entry)
 {
-	/* If it's not a delta, it can't be part of a cycle. */
-	if (!entry->delta) {
-		entry->dfs_state = DFS_DONE;
-		return;
+	/*
+	 * The actual depth of each object we will write is stored as an int,
+	 * as it cannot exceed our int "depth" limit. But before we break
+	 * changes based no that limit, we may potentially go as deep as the
+	 * number of objects, which is elsewhere bounded to a uint32_t.
+	 */
+	uint32_t total_depth;
+	struct object_entry *cur, *next;
+
+	for (cur = entry, total_depth = 0;
+	     cur;
+	     cur = cur->delta, total_depth++) {
+		if (cur->dfs_state == DFS_DONE) {
+			/*
+			 * We've already seen this object and know it isn't
+			 * part of a cycle. We do need to append its depth
+			 * to our count.
+			 */
+			total_depth += cur->depth;
+			break;
+		}
+
+		/*
+		 * We break cycles before looping, so an ACTIVE state (or any
+		 * other cruft which made its way into the state variable)
+		 * is a bug.
+		 */
+		if (cur->dfs_state != DFS_NONE)
+			die("BUG: confusing delta dfs state in first pass: %d",
+			    cur->dfs_state);
+
+		/*
+		 * Now we know this is the first time we've seen the object. If
+		 * it's not a delta, we're done traversing, but we'll mark it
+		 * done to save time on future traversals.
+		 */
+		if (!cur->delta) {
+			cur->dfs_state = DFS_DONE;
+			break;
+		}
+
+		/*
+		 * Mark ourselves as active and see if the next step causes
+		 * us to cycle to another active object. It's important to do
+		 * this _before_ we loop, because it impacts where we make the
+		 * cut, and thus how our total_depth counter works.
+		 * E.g., We may see a partial loop like:
+		 *
+		 *   A -> B -> C -> D -> B
+		 *
+		 * Cutting B->C breaks the cycle. But now the depth of A is
+		 * only 1, and our total_depth counter is at 3. The size of the
+		 * error is always one less than the size of the cycle we
+		 * broke. Commits C and D were "lost" from A's chain.
+		 *
+		 * If we instead cut D->B, then the depth of A is correct at 3.
+		 * We keep all commits in the chain that we examined.
+		 */
+		cur->dfs_state = DFS_ACTIVE;
+		if (cur->delta->dfs_state == DFS_ACTIVE) {
+			drop_reused_delta(cur);
+			cur->dfs_state = DFS_DONE;
+			break;
+		}
 	}
 
-	switch (entry->dfs_state) {
-	case DFS_NONE:
-		/*
-		 * This is the first time we've seen the object. We mark it as
-		 * part of the active potential cycle and recurse.
-		 */
-		entry->dfs_state = DFS_ACTIVE;
-		break_delta_chains(entry->delta);
-		entry->dfs_state = DFS_DONE;
-		break;
+	/*
+	 * And now that we've gone all the way to the bottom of the chain, we
+	 * need to clear the active flags and set the depth fields as
+	 * appropriate. Unlike the loop above, which can quit when it drops a
+	 * delta, we need to keep going to look for more depth cuts. So we need
+	 * an extra "next" pointer to keep going after we reset cur->delta.
+	 */
+	for (cur = entry; cur; cur = next) {
+		next = cur->delta;
 
-	case DFS_DONE:
-		/* object already examined, and not part of a cycle */
-		break;
-
-	case DFS_ACTIVE:
 		/*
-		 * We found a cycle that needs broken. It would be correct to
-		 * break any link in the chain, but it's convenient to
-		 * break this one.
+		 * We should have a chain of zero or more ACTIVE states down to
+		 * a final DONE. We can quit after the DONE, because either it
+		 * has no bases, or we've already handled them in a previous
+		 * call.
 		 */
-		drop_reused_delta(entry);
-		entry->dfs_state = DFS_DONE;
-		break;
+		if (cur->dfs_state == DFS_DONE)
+			break;
+		else if (cur->dfs_state != DFS_ACTIVE)
+			die("BUG: confusing delta dfs state in second pass: %d",
+			    cur->dfs_state);
+
+		/*
+		 * If the total_depth is more than depth, then we need to snip
+		 * the chain into two or more smaller chains that don't exceed
+		 * the maximum depth. Most of the resulting chains will contain
+		 * (depth + 1) entries (i.e., depth deltas plus one base), and
+		 * the last chain (i.e., the one containing entry) will contain
+		 * whatever entries are left over, namely
+		 * (total_depth % (depth + 1)) of them.
+		 *
+		 * Since we are iterating towards decreasing depth, we need to
+		 * decrement total_depth as we go, and we need to write to the
+		 * entry what its final depth will be after all of the
+		 * snipping. Since we're snipping into chains of length (depth
+		 * + 1) entries, the final depth of an entry will be its
+		 * original depth modulo (depth + 1). Any time we encounter an
+		 * entry whose final depth is supposed to be zero, we snip it
+		 * from its delta base, thereby making it so.
+		 */
+		cur->depth = (total_depth--) % (depth + 1);
+		if (!cur->depth)
+			drop_reused_delta(cur);
+
+		cur->dfs_state = DFS_DONE;
 	}
 }
 
@@ -2534,17 +2612,17 @@
 	free(in_pack.array);
 }
 
-static int add_loose_object(const unsigned char *sha1, const char *path,
+static int add_loose_object(const struct object_id *oid, const char *path,
 			    void *data)
 {
-	enum object_type type = sha1_object_info(sha1, NULL);
+	enum object_type type = sha1_object_info(oid->hash, NULL);
 
 	if (type < 0) {
 		warning("loose object at %s could not be examined", path);
 		return 0;
 	}
 
-	add_object_entry(sha1, type, "", 0);
+	add_object_entry(oid->hash, type, "", 0);
 	return 0;
 }
 
diff --git a/builtin/prune-packed.c b/builtin/prune-packed.c
index 7cf900e..c026299 100644
--- a/builtin/prune-packed.c
+++ b/builtin/prune-packed.c
@@ -19,12 +19,12 @@
 	return 0;
 }
 
-static int prune_object(const unsigned char *sha1, const char *path,
+static int prune_object(const struct object_id *oid, const char *path,
 			 void *data)
 {
 	int *opts = data;
 
-	if (!has_sha1_pack(sha1))
+	if (!has_sha1_pack(oid->hash))
 		return 0;
 
 	if (*opts & PRUNE_PACKED_DRY_RUN)
diff --git a/builtin/prune.c b/builtin/prune.c
index 8f4f052..42633e0 100644
--- a/builtin/prune.c
+++ b/builtin/prune.c
@@ -30,7 +30,7 @@
 	return 0;
 }
 
-static int prune_object(const unsigned char *sha1, const char *fullpath,
+static int prune_object(const struct object_id *oid, const char *fullpath,
 			void *data)
 {
 	struct stat st;
@@ -39,7 +39,7 @@
 	 * Do we know about this object?
 	 * It must have been reachable
 	 */
-	if (lookup_object(sha1))
+	if (lookup_object(oid->hash))
 		return 0;
 
 	if (lstat(fullpath, &st)) {
@@ -50,8 +50,8 @@
 	if (st.st_mtime > expire)
 		return 0;
 	if (show_only || verbose) {
-		enum object_type type = sha1_object_info(sha1, NULL);
-		printf("%s %s\n", sha1_to_hex(sha1),
+		enum object_type type = sha1_object_info(oid->hash, NULL);
+		printf("%s %s\n", oid_to_hex(oid),
 		       (type > 0) ? typename(type) : "unknown");
 	}
 	if (!show_only)
diff --git a/builtin/rebase--helper.c b/builtin/rebase--helper.c
new file mode 100644
index 0000000..ca1ebb2
--- /dev/null
+++ b/builtin/rebase--helper.c
@@ -0,0 +1,40 @@
+#include "builtin.h"
+#include "cache.h"
+#include "parse-options.h"
+#include "sequencer.h"
+
+static const char * const builtin_rebase_helper_usage[] = {
+	N_("git rebase--helper [<options>]"),
+	NULL
+};
+
+int cmd_rebase__helper(int argc, const char **argv, const char *prefix)
+{
+	struct replay_opts opts = REPLAY_OPTS_INIT;
+	enum {
+		CONTINUE = 1, ABORT
+	} command = 0;
+	struct option options[] = {
+		OPT_BOOL(0, "ff", &opts.allow_ff, N_("allow fast-forward")),
+		OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
+				CONTINUE),
+		OPT_CMDMODE(0, "abort", &command, N_("abort rebase"),
+				ABORT),
+		OPT_END()
+	};
+
+	git_config(git_default_config, NULL);
+
+	opts.action = REPLAY_INTERACTIVE_REBASE;
+	opts.allow_ff = 1;
+	opts.allow_empty = 1;
+
+	argc = parse_options(argc, argv, NULL, options,
+			builtin_rebase_helper_usage, PARSE_OPT_KEEP_ARGV0);
+
+	if (command == CONTINUE && argc == 1)
+		return !!sequencer_continue(&opts);
+	if (command == ABORT && argc == 1)
+		return !!sequencer_remove_state(&opts);
+	usage_with_options(builtin_rebase_helper_usage, options);
+}
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 1dbb8a0..83492af 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -21,6 +21,7 @@
 #include "sigchain.h"
 #include "fsck.h"
 #include "tmp-objdir.h"
+#include "oidset.h"
 
 static const char * const receive_pack_usage[] = {
 	N_("git receive-pack <git-dir>"),
@@ -250,8 +251,9 @@
 }
 
 static int show_ref_cb(const char *path_full, const struct object_id *oid,
-		       int flag, void *unused)
+		       int flag, void *data)
 {
+	struct oidset *seen = data;
 	const char *path = strip_namespace(path_full);
 
 	if (ref_is_hidden(path, path_full))
@@ -260,37 +262,38 @@
 	/*
 	 * Advertise refs outside our current namespace as ".have"
 	 * refs, so that the client can use them to minimize data
-	 * transfer but will otherwise ignore them. This happens to
-	 * cover ".have" that are thrown in by add_one_alternate_ref()
-	 * to mark histories that are complete in our alternates as
-	 * well.
+	 * transfer but will otherwise ignore them.
 	 */
-	if (!path)
+	if (!path) {
+		if (oidset_insert(seen, oid))
+			return 0;
 		path = ".have";
+	} else {
+		oidset_insert(seen, oid);
+	}
 	show_ref(path, oid->hash);
 	return 0;
 }
 
-static int show_one_alternate_sha1(const unsigned char sha1[20], void *unused)
+static void show_one_alternate_ref(const char *refname,
+				   const struct object_id *oid,
+				   void *data)
 {
-	show_ref(".have", sha1);
-	return 0;
-}
+	struct oidset *seen = data;
 
-static void collect_one_alternate_ref(const struct ref *ref, void *data)
-{
-	struct sha1_array *sa = data;
-	sha1_array_append(sa, ref->old_oid.hash);
+	if (oidset_insert(seen, oid))
+		return;
+
+	show_ref(".have", oid->hash);
 }
 
 static void write_head_info(void)
 {
-	struct sha1_array sa = SHA1_ARRAY_INIT;
+	static struct oidset seen = OIDSET_INIT;
 
-	for_each_alternate_ref(collect_one_alternate_ref, &sa);
-	sha1_array_for_each_unique(&sa, show_one_alternate_sha1, NULL);
-	sha1_array_clear(&sa);
-	for_each_ref(show_ref_cb, NULL);
+	for_each_ref(show_ref_cb, &seen);
+	for_each_alternate_ref(show_one_alternate_ref, &seen);
+	oidset_clear(&seen);
 	if (!sent_capabilities)
 		show_ref("capabilities^{}", null_sha1);
 
@@ -1414,7 +1417,7 @@
 {
 	struct check_connected_options opt = CHECK_CONNECTED_INIT;
 	struct command *cmd;
-	unsigned char sha1[20];
+	struct object_id oid;
 	struct iterate_data data;
 	struct async muxer;
 	int err_fd = 0;
@@ -1471,7 +1474,7 @@
 	check_aliased_updates(commands);
 
 	free(head_name_to_free);
-	head_name = head_name_to_free = resolve_refdup("HEAD", 0, sha1, NULL);
+	head_name = head_name_to_free = resolve_refdup("HEAD", 0, oid.hash, NULL);
 
 	if (use_atomic)
 		execute_commands_atomic(commands, si);
@@ -1664,8 +1667,11 @@
 	}
 
 	tmp_objdir = tmp_objdir_create();
-	if (!tmp_objdir)
+	if (!tmp_objdir) {
+		if (err_fd > 0)
+			close(err_fd);
 		return "unable to create temporary object directory";
+	}
 	child.env = tmp_objdir_env(tmp_objdir);
 
 	/*
diff --git a/builtin/reflog.c b/builtin/reflog.c
index 7a7136e..7472775 100644
--- a/builtin/reflog.c
+++ b/builtin/reflog.c
@@ -615,7 +615,7 @@
 	return status;
 }
 
-static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+static int count_reflog_ent(struct object_id *ooid, struct object_id *noid,
 		const char *email, unsigned long timestamp, int tz,
 		const char *message, void *cb_data)
 {
diff --git a/builtin/remote.c b/builtin/remote.c
index 5339ed6..addf97a 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -691,7 +691,7 @@
 		read_ref_full(item->string, RESOLVE_REF_READING, oid.hash, &flag);
 		if (!(flag & REF_ISSYMREF))
 			continue;
-		if (delete_ref(item->string, NULL, REF_NODEREF))
+		if (delete_ref(NULL, item->string, NULL, REF_NODEREF))
 			die(_("deleting '%s' failed"), item->string);
 	}
 	for (i = 0; i < remote_branches.nr; i++) {
@@ -769,7 +769,9 @@
 				strbuf_reset(&buf);
 				strbuf_addf(&buf, "branch.%s.%s",
 						item->string, *k);
-				git_config_set(buf.buf, NULL);
+				result = git_config_set_gently(buf.buf, NULL);
+				if (result && result != CONFIG_NOTHING_SET)
+					die(_("could not unset '%s'"), buf.buf);
 			}
 		}
 	}
@@ -1248,7 +1250,7 @@
 			head_name = xstrdup(states.heads.items[0].string);
 		free_remote_ref_states(&states);
 	} else if (opt_d && !opt_a && argc == 1) {
-		if (delete_ref(buf.buf, NULL, REF_NODEREF))
+		if (delete_ref(NULL, buf.buf, NULL, REF_NODEREF))
 			result |= error(_("Could not delete %s"), buf.buf);
 	} else
 		usage_with_options(builtin_remote_sethead_usage, options);
diff --git a/builtin/replace.c b/builtin/replace.c
index b58c714..f83e7b8 100644
--- a/builtin/replace.c
+++ b/builtin/replace.c
@@ -88,78 +88,78 @@
 }
 
 typedef int (*each_replace_name_fn)(const char *name, const char *ref,
-				    const unsigned char *sha1);
+				    const struct object_id *oid);
 
 static int for_each_replace_name(const char **argv, each_replace_name_fn fn)
 {
 	const char **p, *full_hex;
 	char ref[PATH_MAX];
 	int had_error = 0;
-	unsigned char sha1[20];
+	struct object_id oid;
 
 	for (p = argv; *p; p++) {
-		if (get_sha1(*p, sha1)) {
+		if (get_oid(*p, &oid)) {
 			error("Failed to resolve '%s' as a valid ref.", *p);
 			had_error = 1;
 			continue;
 		}
-		full_hex = sha1_to_hex(sha1);
+		full_hex = oid_to_hex(&oid);
 		snprintf(ref, sizeof(ref), "%s%s", git_replace_ref_base, full_hex);
 		/* read_ref() may reuse the buffer */
 		full_hex = ref + strlen(git_replace_ref_base);
-		if (read_ref(ref, sha1)) {
+		if (read_ref(ref, oid.hash)) {
 			error("replace ref '%s' not found.", full_hex);
 			had_error = 1;
 			continue;
 		}
-		if (fn(full_hex, ref, sha1))
+		if (fn(full_hex, ref, &oid))
 			had_error = 1;
 	}
 	return had_error;
 }
 
 static int delete_replace_ref(const char *name, const char *ref,
-			      const unsigned char *sha1)
+			      const struct object_id *oid)
 {
-	if (delete_ref(ref, sha1, 0))
+	if (delete_ref(NULL, ref, oid->hash, 0))
 		return 1;
 	printf("Deleted replace ref '%s'\n", name);
 	return 0;
 }
 
-static void check_ref_valid(unsigned char object[20],
-			    unsigned char prev[20],
+static void check_ref_valid(struct object_id *object,
+			    struct object_id *prev,
 			    char *ref,
 			    int ref_size,
 			    int force)
 {
 	if (snprintf(ref, ref_size,
 		     "%s%s", git_replace_ref_base,
-		     sha1_to_hex(object)) > ref_size - 1)
+		     oid_to_hex(object)) > ref_size - 1)
 		die("replace ref name too long: %.*s...", 50, ref);
 	if (check_refname_format(ref, 0))
 		die("'%s' is not a valid ref name.", ref);
 
-	if (read_ref(ref, prev))
-		hashclr(prev);
+	if (read_ref(ref, prev->hash))
+		oidclr(prev);
 	else if (!force)
 		die("replace ref '%s' already exists", ref);
 }
 
-static int replace_object_sha1(const char *object_ref,
-			       unsigned char object[20],
+static int replace_object_oid(const char *object_ref,
+			       struct object_id *object,
 			       const char *replace_ref,
-			       unsigned char repl[20],
+			       struct object_id *repl,
 			       int force)
 {
-	unsigned char prev[20];
+	struct object_id prev;
 	enum object_type obj_type, repl_type;
 	char ref[PATH_MAX];
 	struct ref_transaction *transaction;
 	struct strbuf err = STRBUF_INIT;
 
-	obj_type = sha1_object_info(object, NULL);
-	repl_type = sha1_object_info(repl, NULL);
+	obj_type = sha1_object_info(object->hash, NULL);
+	repl_type = sha1_object_info(repl->hash, NULL);
 	if (!force && obj_type != repl_type)
 		die("Objects must be of the same type.\n"
 		    "'%s' points to a replaced object of type '%s'\n"
@@ -167,11 +167,11 @@
 		    object_ref, typename(obj_type),
 		    replace_ref, typename(repl_type));
 
-	check_ref_valid(object, prev, ref, sizeof(ref), force);
+	check_ref_valid(object, &prev, ref, sizeof(ref), force);
 
 	transaction = ref_transaction_begin(&err);
 	if (!transaction ||
-	    ref_transaction_update(transaction, ref, repl, prev,
+	    ref_transaction_update(transaction, ref, repl->hash, prev.hash,
 				   0, NULL, &err) ||
 	    ref_transaction_commit(transaction, &err))
 		die("%s", err.buf);
@@ -182,14 +182,14 @@
 
 static int replace_object(const char *object_ref, const char *replace_ref, int force)
 {
-	unsigned char object[20], repl[20];
+	struct object_id object, repl;
 
-	if (get_sha1(object_ref, object))
+	if (get_oid(object_ref, &object))
 		die("Failed to resolve '%s' as a valid ref.", object_ref);
-	if (get_sha1(replace_ref, repl))
+	if (get_oid(replace_ref, &repl))
 		die("Failed to resolve '%s' as a valid ref.", replace_ref);
 
-	return replace_object_sha1(object_ref, object, replace_ref, repl, force);
+	return replace_object_oid(object_ref, &object, replace_ref, &repl, force);
 }
 
 /*
@@ -197,7 +197,7 @@
  * If "raw" is true, then the object's raw contents are printed according to
  * "type". Otherwise, we pretty-print the contents for human editing.
  */
-static void export_object(const unsigned char *sha1, enum object_type type,
+static void export_object(const struct object_id *oid, enum object_type type,
 			  int raw, const char *filename)
 {
 	struct child_process cmd = CHILD_PROCESS_INIT;
@@ -213,7 +213,7 @@
 		argv_array_push(&cmd.args, typename(type));
 	else
 		argv_array_push(&cmd.args, "-p");
-	argv_array_push(&cmd.args, sha1_to_hex(sha1));
+	argv_array_push(&cmd.args, oid_to_hex(oid));
 	cmd.git_cmd = 1;
 	cmd.out = fd;
 
@@ -226,7 +226,7 @@
  * interpreting it as "type", and writing the result to the object database.
  * The sha1 of the written object is returned via sha1.
  */
-static void import_object(unsigned char *sha1, enum object_type type,
+static void import_object(struct object_id *oid, enum object_type type,
 			  int raw, const char *filename)
 {
 	int fd;
@@ -254,7 +254,7 @@
 
 		if (finish_command(&cmd))
 			die("mktree reported failure");
-		if (get_sha1_hex(result.buf, sha1) < 0)
+		if (get_oid_hex(result.buf, oid) < 0)
 			die("mktree did not return an object name");
 
 		strbuf_release(&result);
@@ -264,7 +264,7 @@
 
 		if (fstat(fd, &st) < 0)
 			die_errno("unable to fstat %s", filename);
-		if (index_fd(sha1, fd, &st, type, NULL, flags) < 0)
+		if (index_fd(oid->hash, fd, &st, type, NULL, flags) < 0)
 			die("unable to write object to database");
 		/* index_fd close()s fd for us */
 	}
@@ -279,29 +279,29 @@
 {
 	char *tmpfile = git_pathdup("REPLACE_EDITOBJ");
 	enum object_type type;
-	unsigned char old[20], new[20], prev[20];
+	struct object_id old, new, prev;
 	char ref[PATH_MAX];
 
-	if (get_sha1(object_ref, old) < 0)
+	if (get_oid(object_ref, &old) < 0)
 		die("Not a valid object name: '%s'", object_ref);
 
-	type = sha1_object_info(old, NULL);
+	type = sha1_object_info(old.hash, NULL);
 	if (type < 0)
-		die("unable to get object type for %s", sha1_to_hex(old));
+		die("unable to get object type for %s", oid_to_hex(&old));
 
-	check_ref_valid(old, prev, ref, sizeof(ref), force);
+	check_ref_valid(&old, &prev, ref, sizeof(ref), force);
 
-	export_object(old, type, raw, tmpfile);
+	export_object(&old, type, raw, tmpfile);
 	if (launch_editor(tmpfile, NULL, NULL) < 0)
 		die("editing object file failed");
-	import_object(new, type, raw, tmpfile);
+	import_object(&new, type, raw, tmpfile);
 
 	free(tmpfile);
 
-	if (!hashcmp(old, new))
-		return error("new object is the same as the old one: '%s'", sha1_to_hex(old));
+	if (!oidcmp(&old, &new))
+		return error("new object is the same as the old one: '%s'", oid_to_hex(&old));
 
-	return replace_object_sha1(object_ref, old, "replacement", new, force);
+	return replace_object_oid(object_ref, &old, "replacement", &new, force);
 }
 
 static void replace_parents(struct strbuf *buf, int argc, const char **argv)
@@ -312,7 +312,7 @@
 
 	/* find existing parents */
 	parent_start = buf->buf;
-	parent_start += 46; /* "tree " + "hex sha1" + "\n" */
+	parent_start += GIT_SHA1_HEXSZ + 6; /* "tree " + "hex sha1" + "\n" */
 	parent_end = parent_start;
 
 	while (starts_with(parent_end, "parent "))
@@ -320,11 +320,11 @@
 
 	/* prepare new parents */
 	for (i = 0; i < argc; i++) {
-		unsigned char sha1[20];
-		if (get_sha1(argv[i], sha1) < 0)
+		struct object_id oid;
+		if (get_oid(argv[i], &oid) < 0)
 			die(_("Not a valid object name: '%s'"), argv[i]);
-		lookup_commit_or_die(sha1, argv[i]);
-		strbuf_addf(&new_parents, "parent %s\n", sha1_to_hex(sha1));
+		lookup_commit_or_die(oid.hash, argv[i]);
+		strbuf_addf(&new_parents, "parent %s\n", oid_to_hex(&oid));
 	}
 
 	/* replace existing parents with new ones */
@@ -345,12 +345,12 @@
 {
 	struct check_mergetag_data *mergetag_data = (struct check_mergetag_data *)data;
 	const char *ref = mergetag_data->argv[0];
-	unsigned char tag_sha1[20];
+	struct object_id tag_oid;
 	struct tag *tag;
 	int i;
 
-	hash_sha1_file(extra->value, extra->len, typename(OBJ_TAG), tag_sha1);
-	tag = lookup_tag(tag_sha1);
+	hash_sha1_file(extra->value, extra->len, typename(OBJ_TAG), tag_oid.hash);
+	tag = lookup_tag(tag_oid.hash);
 	if (!tag)
 		die(_("bad mergetag in commit '%s'"), ref);
 	if (parse_tag_buffer(tag, extra->value, extra->len))
@@ -366,7 +366,7 @@
 	}
 
 	die(_("original commit '%s' contains mergetag '%s' that is discarded; "
-	      "use --edit instead of --graft"), ref, sha1_to_hex(tag_sha1));
+	      "use --edit instead of --graft"), ref, oid_to_hex(&tag_oid));
 }
 
 static void check_mergetags(struct commit *commit, int argc, const char **argv)
@@ -380,16 +380,16 @@
 
 static int create_graft(int argc, const char **argv, int force)
 {
-	unsigned char old[20], new[20];
+	struct object_id old, new;
 	const char *old_ref = argv[0];
 	struct commit *commit;
 	struct strbuf buf = STRBUF_INIT;
 	const char *buffer;
 	unsigned long size;
 
-	if (get_sha1(old_ref, old) < 0)
+	if (get_oid(old_ref, &old) < 0)
 		die(_("Not a valid object name: '%s'"), old_ref);
-	commit = lookup_commit_or_die(old, old_ref);
+	commit = lookup_commit_or_die(old.hash, old_ref);
 
 	buffer = get_commit_buffer(commit, &size);
 	strbuf_add(&buf, buffer, size);
@@ -404,15 +404,15 @@
 
 	check_mergetags(commit, argc, argv);
 
-	if (write_sha1_file(buf.buf, buf.len, commit_type, new))
+	if (write_sha1_file(buf.buf, buf.len, commit_type, new.hash))
 		die(_("could not write replacement commit for: '%s'"), old_ref);
 
 	strbuf_release(&buf);
 
-	if (!hashcmp(old, new))
-		return error("new commit is the same as the old one: '%s'", sha1_to_hex(old));
+	if (!oidcmp(&old, &new))
+		return error("new commit is the same as the old one: '%s'", oid_to_hex(&old));
 
-	return replace_object_sha1(old_ref, old, "replacement", new, force);
+	return replace_object_oid(old_ref, &old, "replacement", &new, force);
 }
 
 int cmd_replace(int argc, const char **argv, const char *prefix)
diff --git a/builtin/reset.c b/builtin/reset.c
index 8ab915b..fc3b906 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -256,7 +256,7 @@
 		update_ref_oid(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 			   UPDATE_REFS_MSG_ON_ERR);
 	} else if (old_orig)
-		delete_ref("ORIG_HEAD", old_orig->hash, 0);
+		delete_ref(NULL, "ORIG_HEAD", old_orig->hash, 0);
 	set_reflog_message(&msg, "updating HEAD", rev);
 	update_ref_status = update_ref_oid(msg.buf, "HEAD", oid, orig, 0,
 				       UPDATE_REFS_MSG_ON_ERR);
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index ff13e59..2549643 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -12,6 +12,7 @@
 #include "diff.h"
 #include "revision.h"
 #include "split-index.h"
+#include "submodule.h"
 
 #define DO_REVS		1
 #define DO_NOREV	2
@@ -545,6 +546,7 @@
 	unsigned int flags = 0;
 	const char *name = NULL;
 	struct object_context unused;
+	struct strbuf buf = STRBUF_INIT;
 
 	if (argc > 1 && !strcmp("--parseopt", argv[1]))
 		return cmd_parseopt(argc - 1, argv + 1, prefix);
@@ -599,7 +601,9 @@
 		if (!strcmp(arg, "--git-path")) {
 			if (!argv[i + 1])
 				die("--git-path requires an argument");
-			puts(git_path("%s", argv[i + 1]));
+			strbuf_reset(&buf);
+			puts(relative_path(git_path("%s", argv[i + 1]),
+					   prefix, &buf));
 			i++;
 			continue;
 		}
@@ -776,6 +780,12 @@
 					puts(work_tree);
 				continue;
 			}
+			if (!strcmp(arg, "--show-superproject-working-tree")) {
+				const char *superproject = get_superproject_working_tree();
+				if (superproject)
+					puts(superproject);
+				continue;
+			}
 			if (!strcmp(arg, "--show-prefix")) {
 				if (prefix)
 					puts(prefix);
@@ -802,17 +812,27 @@
 				putchar('\n');
 				continue;
 			}
-			if (!strcmp(arg, "--git-dir")) {
+			if (!strcmp(arg, "--git-dir") ||
+			    !strcmp(arg, "--absolute-git-dir")) {
 				const char *gitdir = getenv(GIT_DIR_ENVIRONMENT);
 				char *cwd;
 				int len;
-				if (gitdir) {
-					puts(gitdir);
-					continue;
-				}
-				if (!prefix) {
-					puts(".git");
-					continue;
+				if (arg[2] == 'g') {	/* --git-dir */
+					if (gitdir) {
+						puts(gitdir);
+						continue;
+					}
+					if (!prefix) {
+						puts(".git");
+						continue;
+					}
+				} else {		/* --absolute-git-dir */
+					if (!gitdir && !prefix)
+						gitdir = ".git";
+					if (gitdir) {
+						puts(real_path(gitdir));
+						continue;
+					}
 				}
 				cwd = xgetcwd();
 				len = strlen(cwd);
@@ -821,8 +841,9 @@
 				continue;
 			}
 			if (!strcmp(arg, "--git-common-dir")) {
-				const char *pfx = prefix ? prefix : "";
-				puts(prefix_filename(pfx, strlen(pfx), get_git_common_dir()));
+				strbuf_reset(&buf);
+				puts(relative_path(get_git_common_dir(),
+						   prefix, &buf));
 				continue;
 			}
 			if (!strcmp(arg, "--is-inside-git-dir")) {
@@ -845,7 +866,9 @@
 					die(_("Could not read the index"));
 				if (the_index.split_index) {
 					const unsigned char *sha1 = the_index.split_index->base_sha1;
-					puts(git_path("sharedindex.%s", sha1_to_hex(sha1)));
+					const char *path = git_path("sharedindex.%s", sha1_to_hex(sha1));
+					strbuf_reset(&buf);
+					puts(relative_path(path, prefix, &buf));
 				}
 				continue;
 			}
@@ -897,6 +920,7 @@
 			continue;
 		verify_filename(prefix, arg, 1);
 	}
+	strbuf_release(&buf);
 	if (verify) {
 		if (revs_count == 1) {
 			show_rev(type, sha1, name);
diff --git a/builtin/shortlog.c b/builtin/shortlog.c
index c9585d4..f78bb48 100644
--- a/builtin/shortlog.c
+++ b/builtin/shortlog.c
@@ -148,7 +148,7 @@
 
 	ctx.fmt = CMIT_FMT_USERFORMAT;
 	ctx.abbrev = log->abbrev;
-	ctx.subject = "";
+	ctx.print_email_subject = 1;
 	ctx.after_subject = "";
 	ctx.date_mode.type = DATE_NORMAL;
 	ctx.output_encoding = get_log_output_encoding();
diff --git a/builtin/show-branch.c b/builtin/show-branch.c
index 974f340..1975659 100644
--- a/builtin/show-branch.c
+++ b/builtin/show-branch.c
@@ -275,8 +275,7 @@
 		pp_commit_easy(CMIT_FMT_ONELINE, commit, &pretty);
 		pretty_str = pretty.buf;
 	}
-	if (starts_with(pretty_str, "[PATCH] "))
-		pretty_str += 8;
+	skip_prefix(pretty_str, "[PATCH] ", &pretty_str);
 
 	if (!no_name) {
 		if (name && name->head_name) {
@@ -470,18 +469,14 @@
 	}
 }
 
-static int rev_is_head(char *head, int headlen, char *name,
+static int rev_is_head(const char *head, const char *name,
 		       unsigned char *head_sha1, unsigned char *sha1)
 {
-	if ((!head[0]) ||
-	    (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
+	if (!head || (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
 		return 0;
-	if (starts_with(head, "refs/heads/"))
-		head += 11;
-	if (starts_with(name, "refs/heads/"))
-		name += 11;
-	else if (starts_with(name, "heads/"))
-		name += 6;
+	skip_prefix(head, "refs/heads/", &head);
+	if (!skip_prefix(name, "refs/heads/", &name))
+		skip_prefix(name, "heads/", &name);
 	return !strcmp(head, name);
 }
 
@@ -620,9 +615,7 @@
 	int all_heads = 0, all_remotes = 0;
 	int all_mask, all_revs;
 	enum rev_sort_order sort_order = REV_SORT_IN_GRAPH_ORDER;
-	char head[128];
-	const char *head_p;
-	int head_len;
+	char *head;
 	struct object_id head_oid;
 	int merge_base = 0;
 	int independent = 0;
@@ -787,32 +780,24 @@
 			snarf_refs(all_heads, all_remotes);
 	}
 
-	head_p = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
-				    head_oid.hash, NULL);
-	if (head_p) {
-		head_len = strlen(head_p);
-		memcpy(head, head_p, head_len + 1);
-	}
-	else {
-		head_len = 0;
-		head[0] = 0;
-	}
+	head = resolve_refdup("HEAD", RESOLVE_REF_READING,
+			      head_oid.hash, NULL);
 
-	if (with_current_branch && head_p) {
+	if (with_current_branch && head) {
 		int has_head = 0;
 		for (i = 0; !has_head && i < ref_name_cnt; i++) {
 			/* We are only interested in adding the branch
 			 * HEAD points at.
 			 */
 			if (rev_is_head(head,
-					head_len,
 					ref_name[i],
 					head_oid.hash, NULL))
 				has_head++;
 		}
 		if (!has_head) {
-			int offset = starts_with(head, "refs/heads/") ? 11 : 0;
-			append_one_rev(head + offset);
+			const char *name = head;
+			skip_prefix(name, "refs/heads/", &name);
+			append_one_rev(name);
 		}
 	}
 
@@ -866,7 +851,6 @@
 		for (i = 0; i < num_rev; i++) {
 			int j;
 			int is_head = rev_is_head(head,
-						  head_len,
 						  ref_name[i],
 						  head_oid.hash,
 						  rev[i]->object.oid.hash);
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 899dc33..15a5430 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -356,12 +356,10 @@
 			strbuf_addf(&remotesb, "remote.%s.url", remote);
 			free(remote);
 
-			if (git_config_get_string(remotesb.buf, &remoteurl))
-				/*
-				 * The repository is its own
-				 * authoritative upstream
-				 */
+			if (git_config_get_string(remotesb.buf, &remoteurl)) {
+				warning(_("could not lookup configuration '%s'. Assuming this repository is its own authoritative upstream."), remotesb.buf);
 				remoteurl = xgetcwd();
+			}
 			relurl = relative_url(remoteurl, url, NULL);
 			strbuf_release(&remotesb);
 			free(remoteurl);
diff --git a/builtin/symbolic-ref.c b/builtin/symbolic-ref.c
index 96eed94..70addef 100644
--- a/builtin/symbolic-ref.c
+++ b/builtin/symbolic-ref.c
@@ -58,7 +58,7 @@
 			die("Cannot delete %s, not a symbolic ref", argv[0]);
 		if (!strcmp(argv[0], "HEAD"))
 			die("deleting '%s' is not allowed", argv[0]);
-		return delete_ref(argv[0], NULL, REF_NODEREF);
+		return delete_ref(NULL, argv[0], NULL, REF_NODEREF);
 	}
 
 	switch (argc) {
diff --git a/builtin/tag.c b/builtin/tag.c
index e40c4a9..ad29be6 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -45,11 +45,11 @@
 	if (!format) {
 		if (filter->lines) {
 			to_free = xstrfmt("%s %%(contents:lines=%d)",
-					  "%(align:15)%(refname:strip=2)%(end)",
+					  "%(align:15)%(refname:lstrip=2)%(end)",
 					  filter->lines);
 			format = to_free;
 		} else
-			format = "%(refname:strip=2)";
+			format = "%(refname:lstrip=2)";
 	}
 
 	verify_ref_format(format);
@@ -97,7 +97,7 @@
 static int delete_tag(const char *name, const char *ref,
 		      const unsigned char *sha1, const void *cb_data)
 {
-	if (delete_ref(ref, sha1, 0))
+	if (delete_ref(NULL, ref, sha1, 0))
 		return 1;
 	printf(_("Deleted tag '%s' (was %s)\n"), name, find_unique_abbrev(sha1, DEFAULT_ABBREV));
 	return 0;
@@ -302,6 +302,54 @@
 	}
 }
 
+static void create_reflog_msg(const unsigned char *sha1, struct strbuf *sb)
+{
+	enum object_type type;
+	struct commit *c;
+	char *buf;
+	unsigned long size;
+	int subject_len = 0;
+	const char *subject_start;
+
+	char *rla = getenv("GIT_REFLOG_ACTION");
+	if (rla) {
+		strbuf_addstr(sb, rla);
+	} else {
+		strbuf_addstr(sb, _("tag: tagging "));
+		strbuf_add_unique_abbrev(sb, sha1, DEFAULT_ABBREV);
+	}
+
+	strbuf_addstr(sb, " (");
+	type = sha1_object_info(sha1, NULL);
+	switch (type) {
+	default:
+		strbuf_addstr(sb, _("object of unknown type"));
+		break;
+	case OBJ_COMMIT:
+		if ((buf = read_sha1_file(sha1, &type, &size)) != NULL) {
+			subject_len = find_commit_subject(buf, &subject_start);
+			strbuf_insert(sb, sb->len, subject_start, subject_len);
+		} else {
+			strbuf_addstr(sb, _("commit object"));
+		}
+		free(buf);
+
+		if ((c = lookup_commit_reference(sha1)) != NULL)
+			strbuf_addf(sb, ", %s", show_date(c->date, 0, DATE_MODE(SHORT)));
+		break;
+	case OBJ_TREE:
+		strbuf_addstr(sb, _("tree object"));
+		break;
+	case OBJ_BLOB:
+		strbuf_addstr(sb, _("blob object"));
+		break;
+	case OBJ_TAG:
+		strbuf_addstr(sb, _("other tag object"));
+		break;
+	}
+	strbuf_addch(sb, ')');
+}
+
 struct msg_arg {
 	int given;
 	struct strbuf buf;
@@ -335,6 +383,7 @@
 {
 	struct strbuf buf = STRBUF_INIT;
 	struct strbuf ref = STRBUF_INIT;
+	struct strbuf reflog_msg = STRBUF_INIT;
 	unsigned char object[20], prev[20];
 	const char *object_ref, *tag;
 	struct create_tag_options opt;
@@ -389,6 +438,8 @@
 		OPT_END()
 	};
 
+	setup_ref_filter_porcelain_msg();
+
 	git_config(git_tag_config, sorting_tail);
 
 	memset(&opt, 0, sizeof(opt));
@@ -494,6 +545,8 @@
 	else
 		die(_("Invalid cleanup mode %s"), cleanup_arg);
 
+	create_reflog_msg(object, &reflog_msg);
+
 	if (create_tag_object) {
 		if (force_sign_annotate && !annotate)
 			opt.sign = 1;
@@ -504,7 +557,7 @@
 	if (!transaction ||
 	    ref_transaction_update(transaction, ref.buf, object, prev,
 				   create_reflog ? REF_FORCE_CREATE_REFLOG : 0,
-				   NULL, &err) ||
+				   reflog_msg.buf, &err) ||
 	    ref_transaction_commit(transaction, &err))
 		die("%s", err.buf);
 	ref_transaction_free(transaction);
@@ -514,5 +567,6 @@
 	strbuf_release(&err);
 	strbuf_release(&buf);
 	strbuf_release(&ref);
+	strbuf_release(&reflog_msg);
 	return 0;
 }
diff --git a/builtin/update-index.c b/builtin/update-index.c
index d530e89..d74d72c 100644
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -1099,17 +1099,20 @@
 	}
 
 	if (split_index > 0) {
-		init_split_index(&the_index);
-		the_index.cache_changed |= SPLIT_INDEX_ORDERED;
-	} else if (!split_index && the_index.split_index) {
-		/*
-		 * can't discard_split_index(&the_index); because that
-		 * will destroy split_index->base->cache[], which may
-		 * be shared with the_index.cache[]. So yeah we're
-		 * leaking a bit here.
-		 */
-		the_index.split_index = NULL;
-		the_index.cache_changed |= SOMETHING_CHANGED;
+		if (git_config_get_split_index() == 0)
+			warning(_("core.splitIndex is set to false; "
+				  "remove or change it, if you really want to "
+				  "enable split index"));
+		if (the_index.split_index)
+			the_index.cache_changed |= SPLIT_INDEX_ORDERED;
+		else
+			add_split_index(&the_index);
+	} else if (!split_index) {
+		if (git_config_get_split_index() == 1)
+			warning(_("core.splitIndex is set to true; "
+				  "remove or change it, if you really want to "
+				  "disable split index"));
+		remove_split_index(&the_index);
 	}
 
 	switch (untracked_cache) {
diff --git a/builtin/update-ref.c b/builtin/update-ref.c
index 7f30d3a..0b2ecf4 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -433,7 +433,7 @@
 		 * For purposes of backwards compatibility, we treat
 		 * NULL_SHA1 as "don't care" here:
 		 */
-		return delete_ref(refname,
+		return delete_ref(msg, refname,
 				  (oldval && !is_null_sha1(oldsha1)) ? oldsha1 : NULL,
 				  flags);
 	else
diff --git a/cache.h b/cache.h
index c12bc23..9b2157f 100644
--- a/cache.h
+++ b/cache.h
@@ -10,8 +10,8 @@
 #include "trace.h"
 #include "string-list.h"
 #include "pack-revindex.h"
+#include "hash.h"
 
-#include SHA1_HEADER
 #ifndef platform_SHA_CTX
 /*
  * platform's underlying implementation of SHA-1; could be OpenSSL,
@@ -1052,9 +1052,6 @@
 	return !hashcmp(oid->hash, EMPTY_TREE_SHA1_BIN);
 }
 
-
-int git_mkstemp(char *path, size_t n, const char *template);
-
 /* set default permissions by passing mode arguments to open(2) */
 int git_mkstemps_mode(char *pattern, int suffix_len, int mode);
 int git_mkstemp_mode(char *pattern, int mode);
@@ -1079,8 +1076,9 @@
 
 /*
  * Create the directory containing the named path, using care to be
- * somewhat safe against races.  Return one of the scld_error values
- * to indicate success/failure.
+ * somewhat safe against races. Return one of the scld_error values to
+ * indicate success/failure. On error, set errno to describe the
+ * problem.
  *
  * SCLD_VANISHED indicates that one of the ancestor directories of the
  * path existed at one point during the function call and then
@@ -1104,6 +1102,49 @@
 enum scld_error safe_create_leading_directories(char *path);
 enum scld_error safe_create_leading_directories_const(const char *path);
 
+/*
+ * Callback function for raceproof_create_file(). This function is
+ * expected to do something that makes dirname(path) permanent despite
+ * the fact that other processes might be cleaning up empty
+ * directories at the same time. Usually it will create a file named
+ * path, but alternatively it could create another file in that
+ * directory, or even chdir() into that directory. The function should
+ * return 0 if the action was completed successfully. On error, it
+ * should return a nonzero result and set errno.
+ * raceproof_create_file() treats two errno values specially:
+ *
+ * - ENOENT -- dirname(path) does not exist. In this case,
+ *             raceproof_create_file() tries creating dirname(path)
+ *             (and any parent directories, if necessary) and calls
+ *             the function again.
+ *
+ * - EISDIR -- the file already exists and is a directory. In this
+ *             case, raceproof_create_file() removes the directory if
+ *             it is empty (and recursively any empty directories that
+ *             it contains) and calls the function again.
+ *
+ * Any other errno causes raceproof_create_file() to fail with the
+ * callback's return value and errno.
+ *
+ * Obviously, this function should be OK with being called again if it
+ * fails with ENOENT or EISDIR. In other scenarios it will not be
+ * called again.
+ */
+typedef int create_file_fn(const char *path, void *cb);
+
+/*
+ * Create a file in dirname(path) by calling fn, creating leading
+ * directories if necessary. Retry a few times in case we are racing
+ * with another process that is trying to clean up the directory that
+ * contains path. See the documentation for create_file_fn for more
+ * details.
+ *
+ * Return the value and set the errno that resulted from the most
+ * recent call of fn. fn is always called at least once, and will be
+ * called more than once if it returns ENOENT or EISDIR.
+ */
+int raceproof_create_file(const char *path, create_file_fn fn, void *cb);
+
 int mkdir_in_gitdir(const char *path);
 extern char *expand_user_path(const char *path);
 const char *enter_repo(const char *path, int strict);
@@ -1116,7 +1157,7 @@
 		      int die_on_error);
 const char *real_path(const char *path);
 const char *real_path_if_valid(const char *path);
-char *real_pathdup(const char *path);
+char *real_pathdup(const char *path, int die_on_error);
 const char *absolute_path(const char *path);
 char *absolute_pathdup(const char *path);
 const char *remove_leading_path(const char *in, const char *prefix);
@@ -1236,6 +1277,9 @@
 
 extern void assert_sha1_type(const unsigned char *sha1, enum object_type expect);
 
+/* Helper to check and "touch" a file */
+extern int check_and_freshen_file(const char *fn, int freshen);
+
 extern const signed char hexval_table[256];
 static inline unsigned int hexval(unsigned char c)
 {
@@ -1326,7 +1370,46 @@
 extern char *sha1_to_hex(const unsigned char *sha1);	/* static buffer result! */
 extern char *oid_to_hex(const struct object_id *oid);	/* same static buffer as sha1_to_hex */
 
-extern int interpret_branch_name(const char *str, int len, struct strbuf *);
+/*
+ * Parse a 40-character hexadecimal object ID starting from hex, updating the
+ * pointer specified by end when parsing stops.  The resulting object ID is
+ * stored in oid.  Returns 0 on success.  Parsing will stop on the first NUL or
+ * other invalid character.  end is only updated on success; otherwise, it is
+ * unmodified.
+ */
+extern int parse_oid_hex(const char *hex, struct object_id *oid, const char **end);
+
+/*
+ * This reads short-hand syntax that not only evaluates to a commit
+ * object name, but also can act as if the end user spelled the name
+ * of the branch from the command line.
+ *
+ * - "@{-N}" finds the name of the Nth previous branch we were on, and
+ *   places the name of the branch in the given buf and returns the
+ *   number of characters parsed if successful.
+ *
+ * - "<branch>@{upstream}" finds the name of the other ref that
+ *   <branch> is configured to merge with (missing <branch> defaults
+ *   to the current branch), and places the name of the branch in the
+ *   given buf and returns the number of characters parsed if
+ *   successful.
+ *
+ * If the input is not of the accepted format, it returns a negative
+ * number to signal an error.
+ *
+ * If the input was ok but there are not N branch switches in the
+ * reflog, it returns 0.
+ *
+ * If "allowed" is non-zero, it is a treated as a bitfield of allowable
+ * expansions: local branches ("refs/heads/"), remote branches
+ * ("refs/remotes/"), or "HEAD". If no "allowed" bits are set, any expansion is
+ * allowed, even ones to refs outside of those namespaces.
+ */
+#define INTERPRET_BRANCH_LOCAL (1<<0)
+#define INTERPRET_BRANCH_REMOTE (1<<1)
+#define INTERPRET_BRANCH_HEAD (1<<2)
+extern int interpret_branch_name(const char *str, int len, struct strbuf *,
+				 unsigned allowed);
 extern int get_oid_mb(const char *str, struct object_id *oid);
 
 extern int validate_headref(const char *ref);
@@ -1606,6 +1689,12 @@
  * error.
  */
 extern const unsigned char *nth_packed_object_sha1(struct packed_git *, uint32_t n);
+/*
+ * Like nth_packed_object_sha1, but write the data into the object specified by
+ * the the first argument.  Returns the first argument on success, and NULL on
+ * error.
+ */
+extern const struct object_id *nth_packed_object_oid(struct object_id *, struct packed_git *, uint32_t n);
 
 /*
  * Return the offset of the nth object within the specified packfile.
@@ -1647,7 +1736,7 @@
  * scratch buffer, but restored to its original contents before
  * the function returns.
  */
-typedef int each_loose_object_fn(const unsigned char *sha1,
+typedef int each_loose_object_fn(const struct object_id *oid,
 				 const char *path,
 				 void *data);
 typedef int each_loose_cruft_fn(const char *basename,
@@ -1673,7 +1762,7 @@
  * LOCAL_ONLY flag is set).
  */
 #define FOR_EACH_OBJECT_LOCAL_ONLY 0x1
-typedef int each_packed_object_fn(const unsigned char *sha1,
+typedef int each_packed_object_fn(const struct object_id *oid,
 				  struct packed_git *pack,
 				  uint32_t pos,
 				  void *data);
@@ -1827,8 +1916,11 @@
  *
  * (i.e., what gets handed to a config_fn_t). The caller provides the section;
  * we return -1 if it does not match, 0 otherwise. The subsection and key
- * out-parameters are filled by the function (and subsection is NULL if it is
+ * out-parameters are filled by the function (and *subsection is NULL if it is
  * missing).
+ *
+ * If the subsection pointer-to-pointer passed in is NULL, returns 0 only if
+ * there is no subsection at all.
  */
 extern int parse_config_key(const char *var,
 			    const char *section,
@@ -1890,6 +1982,11 @@
 extern int git_config_get_maybe_bool(const char *key, int *dest);
 extern int git_config_get_pathname(const char *key, const char **dest);
 extern int git_config_get_untracked_cache(void);
+extern int git_config_get_split_index(void);
+extern int git_config_get_max_percent_split_change(void);
+
+/* This dies if the configured or default date is in the future */
+extern int git_config_get_expiry(const char *key, const char **output);
 
 /*
  * This is a hack for test programs like test-dump-untracked-cache to
diff --git a/ci/run-linux32-build.sh b/ci/run-linux32-build.sh
new file mode 100755
index 0000000..e30fb2c
--- /dev/null
+++ b/ci/run-linux32-build.sh
@@ -0,0 +1,30 @@
+#!/bin/sh
+#
+# Build and test Git in a 32-bit environment
+#
+# Usage:
+#   run-linux32-build.sh [host-user-id]
+#
+
+# Update packages to the latest available versions
+linux32 --32bit i386 sh -c '
+    apt update >/dev/null &&
+    apt install -y build-essential libcurl4-openssl-dev libssl-dev \
+	libexpat-dev gettext python >/dev/null
+' &&
+
+# If this script runs inside a docker container, then all commands are
+# usually executed as root. Consequently, the host user might not be
+# able to access the test output files.
+# If a host user id is given, then create a user "ci" with the host user
+# id to make everything accessible to the host user.
+HOST_UID=$1 &&
+CI_USER=$USER &&
+test -z $HOST_UID || (CI_USER="ci" && useradd -u $HOST_UID $CI_USER) &&
+
+# Build and test
+linux32 --32bit i386 su -m -l $CI_USER -c '
+    cd /usr/src/git &&
+    make --jobs=2 &&
+    make --quiet test
+'
diff --git a/commit.c b/commit.c
index 2cf8515..73c78c2 100644
--- a/commit.c
+++ b/commit.c
@@ -415,8 +415,7 @@
 		p++;
 	if (*p) {
 		p = skip_blank_lines(p + 2);
-		for (eol = p; *eol && *eol != '\n'; eol++)
-			; /* do nothing */
+		eol = strchrnul(p, '\n');
 	} else
 		eol = p;
 
@@ -1308,11 +1307,11 @@
 
 static inline int standard_header_field(const char *field, size_t len)
 {
-	return ((len == 4 && !memcmp(field, "tree ", 5)) ||
-		(len == 6 && !memcmp(field, "parent ", 7)) ||
-		(len == 6 && !memcmp(field, "author ", 7)) ||
-		(len == 9 && !memcmp(field, "committer ", 10)) ||
-		(len == 8 && !memcmp(field, "encoding ", 9)));
+	return ((len == 4 && !memcmp(field, "tree", 4)) ||
+		(len == 6 && !memcmp(field, "parent", 6)) ||
+		(len == 6 && !memcmp(field, "author", 6)) ||
+		(len == 9 && !memcmp(field, "committer", 9)) ||
+		(len == 8 && !memcmp(field, "encoding", 8)));
 }
 
 static int excluded_header_field(const char *field, size_t len, const char **exclude)
@@ -1322,8 +1321,7 @@
 
 	while (*exclude) {
 		size_t xlen = strlen(*exclude);
-		if (len == xlen &&
-		    !memcmp(field, *exclude, xlen) && field[xlen] == ' ')
+		if (len == xlen && !memcmp(field, *exclude, xlen))
 			return 1;
 		exclude++;
 	}
@@ -1354,12 +1352,11 @@
 		strbuf_reset(&buf);
 		it = NULL;
 
-		eof = strchr(line, ' ');
-		if (next <= eof)
+		eof = memchr(line, ' ', next - line);
+		if (!eof)
 			eof = next;
-
-		if (standard_header_field(line, eof - line) ||
-		    excluded_header_field(line, eof - line, exclude))
+		else if (standard_header_field(line, eof - line) ||
+			 excluded_header_field(line, eof - line, exclude))
 			continue;
 
 		it = xcalloc(1, sizeof(*it));
diff --git a/commit.h b/commit.h
index 9c12abb..528272a 100644
--- a/commit.h
+++ b/commit.h
@@ -142,21 +142,24 @@
 	return (fmt == CMIT_FMT_EMAIL || fmt == CMIT_FMT_MBOXRD);
 }
 
+struct rev_info; /* in revision.h, it circularly uses enum cmit_fmt */
+
 struct pretty_print_context {
 	/*
 	 * Callers should tweak these to change the behavior of pp_* functions.
 	 */
 	enum cmit_fmt fmt;
 	int abbrev;
-	const char *subject;
 	const char *after_subject;
 	int preserve_subject;
 	struct date_mode date_mode;
 	unsigned date_mode_explicit:1;
+	int print_email_subject;
 	int expand_tabs_in_log;
 	int need_8bit_cte;
 	char *notes_message;
 	struct reflog_walk_info *reflog_info;
+	struct rev_info *rev;
 	const char *output_encoding;
 	struct string_list *mailmap;
 	int color;
@@ -175,7 +178,6 @@
 };
 
 extern int has_non_ascii(const char *text);
-struct rev_info; /* in revision.h, it circularly uses enum cmit_fmt */
 extern const char *logmsg_reencode(const struct commit *commit,
 				   char **commit_encoding,
 				   const char *output_encoding);
diff --git a/common-main.c b/common-main.c
index c654f95..6a68900 100644
--- a/common-main.c
+++ b/common-main.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "exec_cmd.h"
+#include "attr.h"
 
 /*
  * Many parts of Git have subprograms communicate via pipe, expect the
@@ -33,6 +34,8 @@
 
 	git_setup_gettext();
 
+	attr_start();
+
 	git_extract_argv0_path(argv[0]);
 
 	restore_sigpipe_to_default();
diff --git a/config.c b/config.c
index a88df53..eb7e310 100644
--- a/config.c
+++ b/config.c
@@ -201,11 +201,105 @@
 	strbuf_release(&env);
 }
 
+static inline int iskeychar(int c)
+{
+	return isalnum(c) || c == '-';
+}
+
+/*
+ * Auxiliary function to sanity-check and split the key into the section
+ * identifier and variable name.
+ *
+ * Returns 0 on success, -1 when there is an invalid character in the key and
+ * -2 if there is no section name in the key.
+ *
+ * store_key - pointer to char* which will hold a copy of the key with
+ *             lowercase section and variable name
+ * baselen - pointer to int which will hold the length of the
+ *           section + subsection part, can be NULL
+ */
+static int git_config_parse_key_1(const char *key, char **store_key, int *baselen_, int quiet)
+{
+	int i, dot, baselen;
+	const char *last_dot = strrchr(key, '.');
+
+	/*
+	 * Since "key" actually contains the section name and the real
+	 * key name separated by a dot, we have to know where the dot is.
+	 */
+
+	if (last_dot == NULL || last_dot == key) {
+		if (!quiet)
+			error("key does not contain a section: %s", key);
+		return -CONFIG_NO_SECTION_OR_NAME;
+	}
+
+	if (!last_dot[1]) {
+		if (!quiet)
+			error("key does not contain variable name: %s", key);
+		return -CONFIG_NO_SECTION_OR_NAME;
+	}
+
+	baselen = last_dot - key;
+	if (baselen_)
+		*baselen_ = baselen;
+
+	/*
+	 * Validate the key and while at it, lower case it for matching.
+	 */
+	if (store_key)
+		*store_key = xmallocz(strlen(key));
+
+	dot = 0;
+	for (i = 0; key[i]; i++) {
+		unsigned char c = key[i];
+		if (c == '.')
+			dot = 1;
+		/* Leave the extended basename untouched.. */
+		if (!dot || i > baselen) {
+			if (!iskeychar(c) ||
+			    (i == baselen + 1 && !isalpha(c))) {
+				if (!quiet)
+					error("invalid key: %s", key);
+				goto out_free_ret_1;
+			}
+			c = tolower(c);
+		} else if (c == '\n') {
+			if (!quiet)
+				error("invalid key (newline): %s", key);
+			goto out_free_ret_1;
+		}
+		if (store_key)
+			(*store_key)[i] = c;
+	}
+
+	return 0;
+
+out_free_ret_1:
+	if (store_key) {
+		free(*store_key);
+		*store_key = NULL;
+	}
+	return -CONFIG_INVALID_KEY;
+}
+
+int git_config_parse_key(const char *key, char **store_key, int *baselen)
+{
+	return git_config_parse_key_1(key, store_key, baselen, 0);
+}
+
+int git_config_key_is_valid(const char *key)
+{
+	return !git_config_parse_key_1(key, NULL, NULL, 1);
+}
+
 int git_config_parse_parameter(const char *text,
 			       config_fn_t fn, void *data)
 {
 	const char *value;
+	char *canonical_name;
 	struct strbuf **pair;
+	int ret;
 
 	pair = strbuf_split_str(text, '=', 2);
 	if (!pair[0])
@@ -223,13 +317,15 @@
 		strbuf_list_free(pair);
 		return error("bogus config parameter: %s", text);
 	}
-	strbuf_tolower(pair[0]);
-	if (fn(pair[0]->buf, value, data) < 0) {
-		strbuf_list_free(pair);
-		return -1;
+
+	if (git_config_parse_key(pair[0]->buf, &canonical_name, NULL)) {
+		ret = -1;
+	} else {
+		ret = (fn(canonical_name, value, data) < 0) ? -1 : 0;
+		free(canonical_name);
 	}
 	strbuf_list_free(pair);
-	return 0;
+	return ret;
 }
 
 int git_config_from_parameters(config_fn_t fn, void *data)
@@ -356,11 +452,6 @@
 	}
 }
 
-static inline int iskeychar(int c)
-{
-	return isalnum(c) || c == '-';
-}
-
 static int get_value(config_fn_t fn, void *data, struct strbuf *name)
 {
 	int c;
@@ -1737,6 +1828,19 @@
 	return ret;
 }
 
+int git_config_get_expiry(const char *key, const char **output)
+{
+	int ret = git_config_get_string_const(key, output);
+	if (ret)
+		return ret;
+	if (strcmp(*output, "now")) {
+		unsigned long now = approxidate("now");
+		if (approxidate(*output) >= now)
+			git_die_config(key, _("Invalid %s: '%s'"), key, *output);
+	}
+	return ret;
+}
+
 int git_config_get_untracked_cache(void)
 {
 	int val = -1;
@@ -1753,14 +1857,39 @@
 		if (!strcasecmp(v, "keep"))
 			return -1;
 
-		error("unknown core.untrackedCache value '%s'; "
-		      "using 'keep' default value", v);
+		error(_("unknown core.untrackedCache value '%s'; "
+			"using 'keep' default value"), v);
 		return -1;
 	}
 
 	return -1; /* default value */
 }
 
+int git_config_get_split_index(void)
+{
+	int val;
+
+	if (!git_config_get_maybe_bool("core.splitindex", &val))
+		return val;
+
+	return -1; /* default value */
+}
+
+int git_config_get_max_percent_split_change(void)
+{
+	int val = -1;
+
+	if (!git_config_get_int("splitindex.maxpercentchange", &val)) {
+		if (0 <= val && val <= 100)
+			return val;
+
+		return error(_("splitIndex.maxPercentChange value '%d' "
+			       "should be between 0 and 100"), val);
+	}
+
+	return -1; /* default value */
+}
+
 NORETURN
 void git_die_config_linenr(const char *key, const char *filename, int linenr)
 {
@@ -2015,93 +2144,6 @@
 }
 
 /*
- * Auxiliary function to sanity-check and split the key into the section
- * identifier and variable name.
- *
- * Returns 0 on success, -1 when there is an invalid character in the key and
- * -2 if there is no section name in the key.
- *
- * store_key - pointer to char* which will hold a copy of the key with
- *             lowercase section and variable name
- * baselen - pointer to int which will hold the length of the
- *           section + subsection part, can be NULL
- */
-static int git_config_parse_key_1(const char *key, char **store_key, int *baselen_, int quiet)
-{
-	int i, dot, baselen;
-	const char *last_dot = strrchr(key, '.');
-
-	/*
-	 * Since "key" actually contains the section name and the real
-	 * key name separated by a dot, we have to know where the dot is.
-	 */
-
-	if (last_dot == NULL || last_dot == key) {
-		if (!quiet)
-			error("key does not contain a section: %s", key);
-		return -CONFIG_NO_SECTION_OR_NAME;
-	}
-
-	if (!last_dot[1]) {
-		if (!quiet)
-			error("key does not contain variable name: %s", key);
-		return -CONFIG_NO_SECTION_OR_NAME;
-	}
-
-	baselen = last_dot - key;
-	if (baselen_)
-		*baselen_ = baselen;
-
-	/*
-	 * Validate the key and while at it, lower case it for matching.
-	 */
-	if (store_key)
-		*store_key = xmallocz(strlen(key));
-
-	dot = 0;
-	for (i = 0; key[i]; i++) {
-		unsigned char c = key[i];
-		if (c == '.')
-			dot = 1;
-		/* Leave the extended basename untouched.. */
-		if (!dot || i > baselen) {
-			if (!iskeychar(c) ||
-			    (i == baselen + 1 && !isalpha(c))) {
-				if (!quiet)
-					error("invalid key: %s", key);
-				goto out_free_ret_1;
-			}
-			c = tolower(c);
-		} else if (c == '\n') {
-			if (!quiet)
-				error("invalid key (newline): %s", key);
-			goto out_free_ret_1;
-		}
-		if (store_key)
-			(*store_key)[i] = c;
-	}
-
-	return 0;
-
-out_free_ret_1:
-	if (store_key) {
-		free(*store_key);
-		*store_key = NULL;
-	}
-	return -CONFIG_INVALID_KEY;
-}
-
-int git_config_parse_key(const char *key, char **store_key, int *baselen)
-{
-	return git_config_parse_key_1(key, store_key, baselen, 0);
-}
-
-int git_config_key_is_valid(const char *key)
-{
-	return !git_config_parse_key_1(key, NULL, NULL, 1);
-}
-
-/*
  * If value==NULL, unset in (remove from) config,
  * if value_regex!=NULL, disregard key/value pairs where value does not match.
  * if value_regex==CONFIG_REGEX_NONE, do not match any existing values
@@ -2561,11 +2603,10 @@
 		     const char **subsection, int *subsection_len,
 		     const char **key)
 {
-	int section_len = strlen(section);
 	const char *dot;
 
 	/* Does it start with "section." ? */
-	if (!starts_with(var, section) || var[section_len] != '.')
+	if (!skip_prefix(var, section, &var) || *var != '.')
 		return -1;
 
 	/*
@@ -2577,12 +2618,16 @@
 	*key = dot + 1;
 
 	/* Did we have a subsection at all? */
-	if (dot == var + section_len) {
-		*subsection = NULL;
-		*subsection_len = 0;
+	if (dot == var) {
+		if (subsection) {
+			*subsection = NULL;
+			*subsection_len = 0;
+		}
 	}
 	else {
-		*subsection = var + section_len + 1;
+		if (!subsection)
+			return -1;
+		*subsection = var + 1;
 		*subsection_len = dot - *subsection;
 	}
 
diff --git a/config.mak.uname b/config.mak.uname
index 447f36a..399fe19 100644
--- a/config.mak.uname
+++ b/config.mak.uname
@@ -27,7 +27,6 @@
 ifeq ($(uname_S),Linux)
 	HAVE_ALLOCA_H = YesPlease
 	NO_STRLCPY = YesPlease
-	NO_MKSTEMPS = YesPlease
 	HAVE_PATHS_H = YesPlease
 	LIBC_CONTAINS_LIBINTL = YesPlease
 	HAVE_DEV_TTY = YesPlease
@@ -41,7 +40,6 @@
 ifeq ($(uname_S),GNU/kFreeBSD)
 	HAVE_ALLOCA_H = YesPlease
 	NO_STRLCPY = YesPlease
-	NO_MKSTEMPS = YesPlease
 	HAVE_PATHS_H = YesPlease
 	DIR_HAS_BSD_GROUP_SEMANTICS = YesPlease
 	LIBC_CONTAINS_LIBINTL = YesPlease
@@ -55,7 +53,6 @@
 	SHELL_PATH = /usr/local/bin/bash
 	NO_IPV6 = YesPlease
 	NO_HSTRERROR = YesPlease
-	NO_MKSTEMPS = YesPlease
 	BASIC_CFLAGS += -Kthread
 	BASIC_CFLAGS += -I/usr/local/include
 	BASIC_LDFLAGS += -L/usr/local/lib
@@ -79,7 +76,6 @@
 	SHELL_PATH = /usr/bin/bash
 	NO_IPV6 = YesPlease
 	NO_HSTRERROR = YesPlease
-	NO_MKSTEMPS = YesPlease
 	BASIC_CFLAGS += -I/usr/local/include
 	BASIC_LDFLAGS += -L/usr/local/lib
 	NO_STRCASESTR = YesPlease
@@ -122,7 +118,6 @@
 	NO_STRCASESTR = YesPlease
 	NO_MEMMEM = YesPlease
 	NO_MKDTEMP = YesPlease
-	NO_MKSTEMPS = YesPlease
 	NO_REGEX = YesPlease
 	NO_MSGFMT_EXTENDED_OPTIONS = YesPlease
 	HAVE_DEV_TTY = YesPlease
@@ -168,7 +163,6 @@
 		NO_D_TYPE_IN_DIRENT = YesPlease
 		NO_STRCASESTR = YesPlease
 		NO_MEMMEM = YesPlease
-		NO_MKSTEMPS = YesPlease
 		NO_SYMLINK_HEAD = YesPlease
 		NO_IPV6 = YesPlease
 		OLD_ICONV = UnfortunatelyYes
@@ -233,7 +227,6 @@
 	BASIC_CFLAGS += -I/usr/pkg/include
 	BASIC_LDFLAGS += -L/usr/pkg/lib $(CC_LD_DYNPATH)/usr/pkg/lib
 	USE_ST_TIMESPEC = YesPlease
-	NO_MKSTEMPS = YesPlease
 	HAVE_PATHS_H = YesPlease
 	HAVE_BSD_SYSCTL = YesPlease
 endif
@@ -242,7 +235,6 @@
 	NO_STRCASESTR = YesPlease
 	NO_MEMMEM = YesPlease
 	NO_MKDTEMP = YesPlease
-	NO_MKSTEMPS = YesPlease
 	NO_STRLCPY = YesPlease
 	NO_NSEC = YesPlease
 	FREAD_READS_DIRECTORIES = UnfortunatelyYes
@@ -263,7 +255,6 @@
 	# GNU/Hurd
 	HAVE_ALLOCA_H = YesPlease
 	NO_STRLCPY = YesPlease
-	NO_MKSTEMPS = YesPlease
 	HAVE_PATHS_H = YesPlease
 	LIBC_CONTAINS_LIBINTL = YesPlease
 endif
@@ -272,7 +263,6 @@
 	NO_UNSETENV = YesPlease
 	NO_STRCASESTR = YesPlease
 	NO_MEMMEM = YesPlease
-	NO_MKSTEMPS = YesPlease
 	NO_MKDTEMP = YesPlease
 	# When compiled with the MIPSpro 7.4.4m compiler, and without pthreads
 	# (i.e. NO_PTHREADS is set), and _with_ MMAP (i.e. NO_MMAP is not set),
@@ -291,7 +281,6 @@
 	NO_UNSETENV = YesPlease
 	NO_STRCASESTR = YesPlease
 	NO_MEMMEM = YesPlease
-	NO_MKSTEMPS = YesPlease
 	NO_MKDTEMP = YesPlease
 	# When compiled with the MIPSpro 7.4.4m compiler, and without pthreads
 	# (i.e. NO_PTHREADS is set), and _with_ MMAP (i.e. NO_MMAP is not set),
@@ -311,7 +300,6 @@
 	NO_SETENV = YesPlease
 	NO_STRCASESTR = YesPlease
 	NO_MEMMEM = YesPlease
-	NO_MKSTEMPS = YesPlease
 	NO_STRLCPY = YesPlease
 	NO_MKDTEMP = YesPlease
 	NO_UNSETENV = YesPlease
@@ -352,7 +340,6 @@
 	NO_ICONV = YesPlease
 	NO_STRTOUMAX = YesPlease
 	NO_MKDTEMP = YesPlease
-	NO_MKSTEMPS = YesPlease
 	SNPRINTF_RETURNS_BOGUS = YesPlease
 	NO_SVN_TESTS = YesPlease
 	RUNTIME_PREFIX = YesPlease
@@ -402,7 +389,6 @@
 	NO_MKDTEMP = YesPlease
 	NO_STRTOUMAX = YesPlease
 	NO_NSEC = YesPlease
-	NO_MKSTEMPS = YesPlease
 	ifeq ($(uname_R),3.5)
 		NO_INET_NTOP = YesPlease
 		NO_INET_PTON = YesPlease
@@ -461,7 +447,6 @@
 	NO_SETENV = YesPlease
 	NO_UNSETENV = YesPlease
 	NO_MKDTEMP = YesPlease
-	NO_MKSTEMPS = YesPlease
 	# Currently libiconv-1.9.1.
 	OLD_ICONV = UnfortunatelyYes
 	NO_REGEX = YesPlease
@@ -503,7 +488,6 @@
 	NEEDS_LIBICONV = YesPlease
 	NO_STRTOUMAX = YesPlease
 	NO_MKDTEMP = YesPlease
-	NO_MKSTEMPS = YesPlease
 	NO_SVN_TESTS = YesPlease
 	NO_PERL_MAKEMAKER = YesPlease
 	RUNTIME_PREFIX = YesPlease
@@ -515,7 +499,6 @@
 	OBJECT_CREATION_USES_RENAMES = UnfortunatelyNeedsTo
 	NO_REGEX = YesPlease
 	NO_PYTHON = YesPlease
-	BLK_SHA1 = YesPlease
 	ETAGS_TARGET = ETAGS
 	NO_INET_PTON = YesPlease
 	NO_INET_NTOP = YesPlease
@@ -584,7 +567,6 @@
 	NO_ICONV = YesPlease
 	NO_MEMMEM = YesPlease
 	NO_MKDTEMP = YesPlease
-	NO_MKSTEMPS = YesPlease
 	NO_NSEC = YesPlease
 	NO_PTHREADS = YesPlease
 	NO_R_TO_GCC_LINKER = YesPlease
diff --git a/configure.ac b/configure.ac
index 0b15f04..1281655 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1050,12 +1050,6 @@
 [NO_MKDTEMP=YesPlease])
 GIT_CONF_SUBST([NO_MKDTEMP])
 #
-# Define NO_MKSTEMPS if you don't have mkstemps in the C library.
-GIT_CHECK_FUNC(mkstemps,
-[NO_MKSTEMPS=],
-[NO_MKSTEMPS=YesPlease])
-GIT_CONF_SUBST([NO_MKSTEMPS])
-#
 # Define NO_INITGROUPS if you don't have initgroups in the C library.
 GIT_CHECK_FUNC(initgroups,
 [NO_INITGROUPS=],
diff --git a/connect.c b/connect.c
index 8cb93b0..7d65c1c 100644
--- a/connect.c
+++ b/connect.c
@@ -691,6 +691,68 @@
 	return NULL;
 }
 
+static int override_ssh_variant(int *port_option, int *needs_batch)
+{
+	char *variant;
+
+	variant = xstrdup_or_null(getenv("GIT_SSH_VARIANT"));
+	if (!variant &&
+	    git_config_get_string("ssh.variant", &variant))
+		return 0;
+
+	if (!strcmp(variant, "plink") || !strcmp(variant, "putty")) {
+		*port_option = 'P';
+		*needs_batch = 0;
+	} else if (!strcmp(variant, "tortoiseplink")) {
+		*port_option = 'P';
+		*needs_batch = 1;
+	} else {
+		*port_option = 'p';
+		*needs_batch = 0;
+	}
+	free(variant);
+	return 1;
+}
+
+static void handle_ssh_variant(const char *ssh_command, int is_cmdline,
+			       int *port_option, int *needs_batch)
+{
+	const char *variant;
+	char *p = NULL;
+
+	if (override_ssh_variant(port_option, needs_batch))
+		return;
+
+	if (!is_cmdline) {
+		p = xstrdup(ssh_command);
+		variant = basename(p);
+	} else {
+		const char **ssh_argv;
+
+		p = xstrdup(ssh_command);
+		if (split_cmdline(p, &ssh_argv)) {
+			variant = basename((char *)ssh_argv[0]);
+			/*
+			 * At this point, variant points into the buffer
+			 * referenced by p, hence we do not need ssh_argv
+			 * any longer.
+			 */
+			free(ssh_argv);
+		} else
+			return;
+	}
+
+	if (!strcasecmp(variant, "plink") ||
+	    !strcasecmp(variant, "plink.exe"))
+		*port_option = 'P';
+	else if (!strcasecmp(variant, "tortoiseplink") ||
+		 !strcasecmp(variant, "tortoiseplink.exe")) {
+		*port_option = 'P';
+		*needs_batch = 1;
+	}
+	free(p);
+}
+
 /*
  * This returns a dummy child_process if the transport protocol does not
  * need fork(2), or a struct child_process object if it does.  Once done,
@@ -769,7 +831,8 @@
 		conn->in = conn->out = -1;
 		if (protocol == PROTO_SSH) {
 			const char *ssh;
-			int putty = 0, tortoiseplink = 0;
+			int needs_batch = 0;
+			int port_option = 'p';
 			char *ssh_host = hostandport;
 			const char *port = NULL;
 			transport_check_allowed("ssh");
@@ -792,10 +855,10 @@
 			}
 
 			ssh = get_ssh_command();
-			if (!ssh) {
-				const char *base;
-				char *ssh_dup;
-
+			if (ssh)
+				handle_ssh_variant(ssh, 1, &port_option,
+						   &needs_batch);
+			else {
 				/*
 				 * GIT_SSH is the no-shell version of
 				 * GIT_SSH_COMMAND (and must remain so for
@@ -806,17 +869,10 @@
 				ssh = getenv("GIT_SSH");
 				if (!ssh)
 					ssh = "ssh";
-
-				ssh_dup = xstrdup(ssh);
-				base = basename(ssh_dup);
-
-				tortoiseplink = !strcasecmp(base, "tortoiseplink") ||
-					!strcasecmp(base, "tortoiseplink.exe");
-				putty = tortoiseplink ||
-					!strcasecmp(base, "plink") ||
-					!strcasecmp(base, "plink.exe");
-
-				free(ssh_dup);
+				else
+					handle_ssh_variant(ssh, 0,
+							   &port_option,
+							   &needs_batch);
 			}
 
 			argv_array_push(&conn->args, ssh);
@@ -824,11 +880,11 @@
 				argv_array_push(&conn->args, "-4");
 			else if (flags & CONNECT_IPV6)
 				argv_array_push(&conn->args, "-6");
-			if (tortoiseplink)
+			if (needs_batch)
 				argv_array_push(&conn->args, "-batch");
 			if (port) {
-				/* P is for PuTTY, p is for OpenSSH */
-				argv_array_push(&conn->args, putty ? "-P" : "-p");
+				argv_array_pushf(&conn->args,
+						 "-%c", port_option);
 				argv_array_push(&conn->args, port);
 			}
 			argv_array_push(&conn->args, ssh_host);
diff --git a/contrib/coccinelle/array.cocci b/contrib/coccinelle/array.cocci
index 2d7f25d..4ba98b7 100644
--- a/contrib/coccinelle/array.cocci
+++ b/contrib/coccinelle/array.cocci
@@ -24,3 +24,19 @@
 @@
 - memcpy(dst, src, n * sizeof(T));
 + COPY_ARRAY(dst, src, n);
+
+@@
+type T;
+T *ptr;
+expression n;
+@@
+- ptr = xmalloc(n * sizeof(*ptr));
++ ALLOC_ARRAY(ptr, n);
+
+@@
+type T;
+T *ptr;
+expression n;
+@@
+- ptr = xmalloc(n * sizeof(T));
++ ALLOC_ARRAY(ptr, n);
diff --git a/contrib/coccinelle/strbuf.cocci b/contrib/coccinelle/strbuf.cocci
index 63995f2..1d580e4 100644
--- a/contrib/coccinelle/strbuf.cocci
+++ b/contrib/coccinelle/strbuf.cocci
@@ -38,3 +38,9 @@
 @@
 - strbuf_addstr(E1, find_unique_abbrev(E2, E3));
 + strbuf_add_unique_abbrev(E1, E2, E3);
+
+@@
+expression E1, E2;
+@@
+- strbuf_addstr(E1, real_path(E2));
++ strbuf_add_real_path(E1, E2);
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 41ee529..fc32286 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -34,21 +34,41 @@
 *)   COMP_WORDBREAKS="$COMP_WORDBREAKS:"
 esac
 
+# Discovers the path to the git repository taking any '--git-dir=<path>' and
+# '-C <path>' options into account and stores it in the $__git_repo_path
+# variable.
+__git_find_repo_path ()
+{
+	if [ -n "$__git_repo_path" ]; then
+		# we already know where it is
+		return
+	fi
+
+	if [ -n "${__git_C_args-}" ]; then
+		__git_repo_path="$(git "${__git_C_args[@]}" \
+			${__git_dir:+--git-dir="$__git_dir"} \
+			rev-parse --absolute-git-dir 2>/dev/null)"
+	elif [ -n "${__git_dir-}" ]; then
+		test -d "$__git_dir" &&
+		__git_repo_path="$__git_dir"
+	elif [ -n "${GIT_DIR-}" ]; then
+		test -d "${GIT_DIR-}" &&
+		__git_repo_path="$GIT_DIR"
+	elif [ -d .git ]; then
+		__git_repo_path=.git
+	else
+		__git_repo_path="$(git rev-parse --git-dir 2>/dev/null)"
+	fi
+}
+
+# Deprecated: use __git_find_repo_path() and $__git_repo_path instead
 # __gitdir accepts 0 or 1 arguments (i.e., location)
 # returns location of .git repo
 __gitdir ()
 {
 	if [ -z "${1-}" ]; then
-		if [ -n "${__git_dir-}" ]; then
-			echo "$__git_dir"
-		elif [ -n "${GIT_DIR-}" ]; then
-			test -d "${GIT_DIR-}" || return 1
-			echo "$GIT_DIR"
-		elif [ -d .git ]; then
-			echo .git
-		else
-			git rev-parse --git-dir 2>/dev/null
-		fi
+		__git_find_repo_path || return 1
+		echo "$__git_repo_path"
 	elif [ -d "$1/.git" ]; then
 		echo "$1/.git"
 	else
@@ -56,6 +76,14 @@
 	fi
 }
 
+# Runs git with all the options given as argument, respecting any
+# '--git-dir=<path>' and '-C <path>' options present on the command line
+__git ()
+{
+	git ${__git_C_args:+"${__git_C_args[@]}"} \
+		${__git_dir:+--git-dir="$__git_dir"} "$@" 2>/dev/null
+}
+
 # The following function is based on code from:
 #
 #   bash_completion - programmable completion functions for bash 3.2+
@@ -283,11 +311,11 @@
 __git_ls_files_helper ()
 {
 	if [ "$2" == "--committable" ]; then
-		git -C "$1" diff-index --name-only --relative HEAD
+		__git -C "$1" diff-index --name-only --relative HEAD
 	else
 		# NOTE: $2 is not quoted in order to support multiple options
-		git -C "$1" ls-files --exclude-standard $2
-	fi 2>/dev/null
+		__git -C "$1" ls-files --exclude-standard $2
+	fi
 }
 
 
@@ -299,47 +327,61 @@
 #    slash.
 __git_index_files ()
 {
-	local dir="$(__gitdir)" root="${2-.}" file
+	local root="${2-.}" file
 
-	if [ -d "$dir" ]; then
-		__git_ls_files_helper "$root" "$1" |
-		while read -r file; do
-			case "$file" in
-			?*/*) echo "${file%%/*}" ;;
-			*) echo "$file" ;;
-			esac
-		done | sort | uniq
-	fi
+	__git_ls_files_helper "$root" "$1" |
+	while read -r file; do
+		case "$file" in
+		?*/*) echo "${file%%/*}" ;;
+		*) echo "$file" ;;
+		esac
+	done | sort | uniq
 }
 
 __git_heads ()
 {
-	local dir="$(__gitdir)"
-	if [ -d "$dir" ]; then
-		git --git-dir="$dir" for-each-ref --format='%(refname:short)' \
-			refs/heads
-		return
-	fi
+	__git for-each-ref --format='%(refname:short)' refs/heads
 }
 
 __git_tags ()
 {
-	local dir="$(__gitdir)"
-	if [ -d "$dir" ]; then
-		git --git-dir="$dir" for-each-ref --format='%(refname:short)' \
-			refs/tags
-		return
-	fi
+	__git for-each-ref --format='%(refname:short)' refs/tags
 }
 
-# __git_refs accepts 0, 1 (to pass to __gitdir), or 2 arguments
-# presence of 2nd argument means use the guess heuristic employed
-# by checkout for tracking branches
+# Lists refs from the local (by default) or from a remote repository.
+# It accepts 0, 1 or 2 arguments:
+# 1: The remote to list refs from (optional; ignored, if set but empty).
+#    Can be the name of a configured remote, a path, or a URL.
+# 2: In addition to local refs, list unique branches from refs/remotes/ for
+#    'git checkout's tracking DWIMery (optional; ignored, if set but empty).
 __git_refs ()
 {
-	local i hash dir="$(__gitdir "${1-}")" track="${2-}"
+	local i hash dir track="${2-}"
+	local list_refs_from=path remote="${1-}"
 	local format refs pfx
-	if [ -d "$dir" ]; then
+
+	__git_find_repo_path
+	dir="$__git_repo_path"
+
+	if [ -z "$remote" ]; then
+		if [ -z "$dir" ]; then
+			return
+		fi
+	else
+		if __git_is_configured_remote "$remote"; then
+			# configured remote takes precedence over a
+			# local directory with the same name
+			list_refs_from=remote
+		elif [ -d "$remote/.git" ]; then
+			dir="$remote/.git"
+		elif [ -d "$remote" ]; then
+			dir="$remote"
+		else
+			list_refs_from=url
+		fi
+	fi
+
+	if [ "$list_refs_from" = path ]; then
 		case "$cur" in
 		refs|refs/*)
 			format="refname"
@@ -355,14 +397,14 @@
 			refs="refs/tags refs/heads refs/remotes"
 			;;
 		esac
-		git --git-dir="$dir" for-each-ref --format="$pfx%($format)" \
+		__git_dir="$dir" __git for-each-ref --format="$pfx%($format)" \
 			$refs
 		if [ -n "$track" ]; then
 			# employ the heuristic used by git checkout
 			# Try to find a remote branch that matches the completion word
 			# but only output if the branch name is unique
 			local ref entry
-			git --git-dir="$dir" for-each-ref --shell --format="ref=%(refname:short)" \
+			__git for-each-ref --shell --format="ref=%(refname:short)" \
 				"refs/remotes/" | \
 			while read -r entry; do
 				eval "$entry"
@@ -376,7 +418,7 @@
 	fi
 	case "$cur" in
 	refs|refs/*)
-		git ls-remote "$dir" "$cur*" 2>/dev/null | \
+		__git ls-remote "$remote" "$cur*" | \
 		while read -r hash i; do
 			case "$i" in
 			*^{}) ;;
@@ -385,9 +427,21 @@
 		done
 		;;
 	*)
-		echo "HEAD"
-		git for-each-ref --format="%(refname:short)" -- \
-			"refs/remotes/$dir/" 2>/dev/null | sed -e "s#^$dir/##"
+		if [ "$list_refs_from" = remote ]; then
+			echo "HEAD"
+			__git for-each-ref --format="%(refname:short)" \
+				"refs/remotes/$remote/" | sed -e "s#^$remote/##"
+		else
+			__git ls-remote "$remote" HEAD \
+				"refs/tags/*" "refs/heads/*" "refs/remotes/*" |
+			while read -r hash i; do
+				case "$i" in
+				*^{})	;;
+				refs/*)	echo "${i#refs/*/}" ;;
+				*)	echo "$i" ;;  # symbolic refs
+				esac
+			done
+		fi
 		;;
 	esac
 }
@@ -405,7 +459,7 @@
 __git_refs_remotes ()
 {
 	local i hash
-	git ls-remote "$1" 'refs/heads/*' 2>/dev/null | \
+	__git ls-remote "$1" 'refs/heads/*' | \
 	while read -r hash i; do
 		echo "$i:refs/remotes/$1/${i#refs/heads/}"
 	done
@@ -413,9 +467,21 @@
 
 __git_remotes ()
 {
-	local d="$(__gitdir)"
-	test -d "$d/remotes" && ls -1 "$d/remotes"
-	git --git-dir="$d" remote
+	__git_find_repo_path
+	test -d "$__git_repo_path/remotes" && ls -1 "$__git_repo_path/remotes"
+	__git remote
+}
+
+# Returns true if $1 matches the name of a configured remote, false otherwise.
+__git_is_configured_remote ()
+{
+	local remote
+	for remote in $(__git_remotes); do
+		if [ "$remote" = "$1" ]; then
+			return 0
+		fi
+	done
+	return 1
 }
 
 __git_list_merge_strategies ()
@@ -469,7 +535,7 @@
 		*)   pfx="$ref:$pfx" ;;
 		esac
 
-		__gitcomp_nl "$(git --git-dir="$(__gitdir)" ls-tree "$ls" 2>/dev/null \
+		__gitcomp_nl "$(__git ls-tree "$ls" \
 				| sed '/^100... blob /{
 				           s,^.*	,,
 				           s,$, ,
@@ -747,7 +813,7 @@
 __git_get_config_variables ()
 {
 	local section="$1" i IFS=$'\n'
-	for i in $(git --git-dir="$(__gitdir)" config --name-only --get-regexp "^$section\..*" 2>/dev/null); do
+	for i in $(__git config --name-only --get-regexp "^$section\..*"); do
 		echo "${i#$section.}"
 	done
 }
@@ -765,8 +831,7 @@
 # __git_aliased_command requires 1 argument
 __git_aliased_command ()
 {
-	local word cmdline=$(git --git-dir="$(__gitdir)" \
-		config --get "alias.$1")
+	local word cmdline=$(__git config --get "alias.$1")
 	for word in $cmdline; do
 		case "$word" in
 		\!gitk|gitk)
@@ -842,7 +907,7 @@
 	done
 
 	if [ -n "$config_key" ] && [ -z "$result" ]; then
-		result="$(git --git-dir="$(__gitdir)" config "$config_key")"
+		result="$(__git config "$config_key")"
 	fi
 
 	echo "$result"
@@ -901,8 +966,8 @@
 
 _git_am ()
 {
-	local dir="$(__gitdir)"
-	if [ -d "$dir"/rebase-apply ]; then
+	__git_find_repo_path
+	if [ -d "$__git_repo_path"/rebase-apply ]; then
 		__gitcomp "--skip --continue --resolved --abort"
 		return
 	fi
@@ -990,7 +1055,8 @@
 	local subcommands="start bad good skip reset visualize replay log run"
 	local subcommand="$(__git_find_on_cmdline "$subcommands")"
 	if [ -z "$subcommand" ]; then
-		if [ -f "$(__gitdir)"/BISECT_START ]; then
+		__git_find_repo_path
+		if [ -f "$__git_repo_path"/BISECT_START ]; then
 			__gitcomp "$subcommands"
 		else
 			__gitcomp "replay start"
@@ -1096,8 +1162,8 @@
 
 _git_cherry_pick ()
 {
-	local dir="$(__gitdir)"
-	if [ -f "$dir"/CHERRY_PICK_HEAD ]; then
+	__git_find_repo_path
+	if [ -f "$__git_repo_path"/CHERRY_PICK_HEAD ]; then
 		__gitcomp "--continue --quit --abort"
 		return
 	fi
@@ -1192,7 +1258,7 @@
 		return
 	esac
 
-	if git rev-parse --verify --quiet HEAD >/dev/null; then
+	if __git rev-parse --verify --quiet HEAD >/dev/null; then
 		__git_complete_index_file "--committable"
 	else
 		# This is the first commit
@@ -1207,6 +1273,7 @@
 		__gitcomp "
 			--all --tags --contains --abbrev= --candidates=
 			--exact-match --debug --long --match --always --first-parent
+			--exclude
 			"
 		return
 	esac
@@ -1500,10 +1567,10 @@
 _git_log ()
 {
 	__git_has_doubledash && return
+	__git_find_repo_path
 
-	local g="$(git rev-parse --git-dir 2>/dev/null)"
 	local merge=""
-	if [ -f "$g/MERGE_HEAD" ]; then
+	if [ -f "$__git_repo_path/MERGE_HEAD" ]; then
 		merge="--merge"
 	fi
 	case "$cur" in
@@ -1750,11 +1817,12 @@
 
 _git_rebase ()
 {
-	local dir="$(__gitdir)"
-	if [ -f "$dir"/rebase-merge/interactive ]; then
+	__git_find_repo_path
+	if [ -f "$__git_repo_path"/rebase-merge/interactive ]; then
 		__gitcomp "--continue --skip --abort --quit --edit-todo"
 		return
-	elif [ -d "$dir"/rebase-apply ] || [ -d "$dir"/rebase-merge ]; then
+	elif [ -d "$__git_repo_path"/rebase-apply ] || \
+	     [ -d "$__git_repo_path"/rebase-merge ]; then
 		__gitcomp "--continue --skip --abort --quit"
 		return
 	fi
@@ -1802,9 +1870,7 @@
 {
 	case "$prev" in
 	--to|--cc|--bcc|--from)
-		__gitcomp "
-		$(git --git-dir="$(__gitdir)" send-email --dump-aliases 2>/dev/null)
-		"
+		__gitcomp "$(__git send-email --dump-aliases)"
 		return
 		;;
 	esac
@@ -1834,9 +1900,7 @@
 		return
 		;;
 	--to=*|--cc=*|--bcc=*|--from=*)
-		__gitcomp "
-		$(git --git-dir="$(__gitdir)" send-email --dump-aliases 2>/dev/null)
-		" "" "${cur#--*=}"
+		__gitcomp "$(__git send-email --dump-aliases)" "" "${cur#--*=}"
 		return
 		;;
 	--*)
@@ -1930,7 +1994,7 @@
 		c=$((--c))
 	done
 
-	git --git-dir="$(__gitdir)" config $config_file --name-only --list 2>/dev/null
+	__git config $config_file --name-only --list
 }
 
 _git_config ()
@@ -1965,9 +2029,8 @@
 	remote.*.push)
 		local remote="${prev#remote.}"
 		remote="${remote%.push}"
-		__gitcomp_nl "$(git --git-dir="$(__gitdir)" \
-			for-each-ref --format='%(refname):%(refname)' \
-			refs/heads)"
+		__gitcomp_nl "$(__git for-each-ref \
+			--format='%(refname):%(refname)' refs/heads)"
 		return
 		;;
 	pull.twohead|pull.octopus)
@@ -2482,8 +2545,8 @@
 
 _git_revert ()
 {
-	local dir="$(__gitdir)"
-	if [ -f "$dir"/REVERT_HEAD ]; then
+	__git_find_repo_path
+	if [ -f "$__git_repo_path"/REVERT_HEAD ]; then
 		__gitcomp "--continue --quit --abort"
 		return
 	fi
@@ -2606,12 +2669,12 @@
 			if [ $cword -eq 3 ]; then
 				__gitcomp_nl "$(__git_refs)";
 			else
-				__gitcomp_nl "$(git --git-dir="$(__gitdir)" stash list \
+				__gitcomp_nl "$(__git stash list \
 						| sed -n -e 's/:.*//p')"
 			fi
 			;;
 		show,*|apply,*|drop,*|pop,*)
-			__gitcomp_nl "$(git --git-dir="$(__gitdir)" stash list \
+			__gitcomp_nl "$(__git stash list \
 					| sed -n -e 's/:.*//p')"
 			;;
 		*)
@@ -2838,7 +2901,8 @@
 
 __git_main ()
 {
-	local i c=1 command __git_dir
+	local i c=1 command __git_dir __git_repo_path
+	local __git_C_args C_args_count=0
 
 	while [ $c -lt $cword ]; do
 		i="${words[c]}"
@@ -2848,6 +2912,10 @@
 		--bare)      __git_dir="." ;;
 		--help) command="help"; break ;;
 		-c|--work-tree|--namespace) ((c++)) ;;
+		-C)	__git_C_args[C_args_count++]=-C
+			((c++))
+			__git_C_args[C_args_count++]="${words[c]}"
+			;;
 		-*) ;;
 		*) command="$i"; break ;;
 		esac
@@ -2855,6 +2923,17 @@
 	done
 
 	if [ -z "$command" ]; then
+		case "$prev" in
+		--git-dir|-C|--work-tree)
+			# these need a path argument, let's fall back to
+			# Bash filename completion
+			return
+			;;
+		-c|--namespace)
+			# we don't support completing these options' arguments
+			return
+			;;
+		esac
 		case "$cur" in
 		--*)   __gitcomp "
 			--paginate
@@ -2880,13 +2959,13 @@
 	fi
 
 	local completion_func="_git_${command//-/_}"
-	declare -f $completion_func >/dev/null && $completion_func && return
+	declare -f $completion_func >/dev/null 2>/dev/null && $completion_func && return
 
 	local expansion=$(__git_aliased_command "$command")
 	if [ -n "$expansion" ]; then
 		words[1]=$expansion
 		completion_func="_git_${expansion//-/_}"
-		declare -f $completion_func >/dev/null && $completion_func
+		declare -f $completion_func >/dev/null 2>/dev/null && $completion_func
 	fi
 }
 
@@ -2894,9 +2973,11 @@
 {
 	__git_has_doubledash && return
 
-	local g="$(__gitdir)"
+	local __git_repo_path
+	__git_find_repo_path
+
 	local merge=""
-	if [ -f "$g/MERGE_HEAD" ]; then
+	if [ -f "$__git_repo_path/MERGE_HEAD" ]; then
 		merge="--merge"
 	fi
 	case "$cur" in
diff --git a/contrib/remote-helpers/git-remote-bzr b/contrib/remote-helpers/git-remote-bzr
index 712a137..1c3d87f 100755
--- a/contrib/remote-helpers/git-remote-bzr
+++ b/contrib/remote-helpers/git-remote-bzr
@@ -1,13 +1,11 @@
-#!/usr/bin/env python
+#!/bin/sh
 
-import sys
-
-sys.stderr.write('WARNING: git-remote-bzr is now maintained independently.\n')
-sys.stderr.write('WARNING: For more information visit https://github.com/felipec/git-remote-bzr\n')
-
-sys.stderr.write('''WARNING:
+cat >&2 <<'EOT'
+WARNING: git-remote-bzr is now maintained independently.
+WARNING: For more information visit https://github.com/felipec/git-remote-bzr
+WARNING:
 WARNING: You can pick a directory on your $PATH and download it, e.g.:
-WARNING:   $ wget -O $HOME/bin/git-remote-bzr \\
+WARNING:   $ wget -O $HOME/bin/git-remote-bzr \
 WARNING:     https://raw.github.com/felipec/git-remote-bzr/master/git-remote-bzr
 WARNING:   $ chmod +x $HOME/bin/git-remote-bzr
-''')
+EOT
diff --git a/contrib/remote-helpers/git-remote-hg b/contrib/remote-helpers/git-remote-hg
index 4255ad6..8e91883 100755
--- a/contrib/remote-helpers/git-remote-hg
+++ b/contrib/remote-helpers/git-remote-hg
@@ -1,13 +1,11 @@
-#!/usr/bin/env python
+#!/bin/sh
 
-import sys
-
-sys.stderr.write('WARNING: git-remote-hg is now maintained independently.\n')
-sys.stderr.write('WARNING: For more information visit https://github.com/felipec/git-remote-hg\n')
-
-sys.stderr.write('''WARNING:
+cat >&2 <<'EOT'
+WARNING: git-remote-hg is now maintained independently.
+WARNING: For more information visit https://github.com/felipec/git-remote-hg
+WARNING:
 WARNING: You can pick a directory on your $PATH and download it, e.g.:
-WARNING:   $ wget -O $HOME/bin/git-remote-hg \\
+WARNING:   $ wget -O $HOME/bin/git-remote-hg \
 WARNING:     https://raw.github.com/felipec/git-remote-hg/master/git-remote-hg
 WARNING:   $ chmod +x $HOME/bin/git-remote-hg
-''')
+EOT
diff --git a/convert.c b/convert.c
index 4e17e45..8d652bf 100644
--- a/convert.c
+++ b/convert.c
@@ -1028,7 +1028,7 @@
 	return 1;
 }
 
-static enum crlf_action git_path_check_crlf(struct git_attr_check *check)
+static enum crlf_action git_path_check_crlf(struct attr_check_item *check)
 {
 	const char *value = check->value;
 
@@ -1045,7 +1045,7 @@
 	return CRLF_UNDEFINED;
 }
 
-static enum eol git_path_check_eol(struct git_attr_check *check)
+static enum eol git_path_check_eol(struct attr_check_item *check)
 {
 	const char *value = check->value;
 
@@ -1058,7 +1058,7 @@
 	return EOL_UNSET;
 }
 
-static struct convert_driver *git_path_check_convert(struct git_attr_check *check)
+static struct convert_driver *git_path_check_convert(struct attr_check_item *check)
 {
 	const char *value = check->value;
 	struct convert_driver *drv;
@@ -1071,7 +1071,7 @@
 	return NULL;
 }
 
-static int git_path_check_ident(struct git_attr_check *check)
+static int git_path_check_ident(struct attr_check_item *check)
 {
 	const char *value = check->value;
 
@@ -1085,24 +1085,19 @@
 	int ident;
 };
 
-static const char *conv_attr_name[] = {
-	"crlf", "ident", "filter", "eol", "text",
-};
-#define NUM_CONV_ATTRS ARRAY_SIZE(conv_attr_name)
-
 static void convert_attrs(struct conv_attrs *ca, const char *path)
 {
-	int i;
-	static struct git_attr_check ccheck[NUM_CONV_ATTRS];
+	static struct attr_check *check;
 
-	if (!ccheck[0].attr) {
-		for (i = 0; i < NUM_CONV_ATTRS; i++)
-			ccheck[i].attr = git_attr(conv_attr_name[i]);
+	if (!check) {
+		check = attr_check_initl("crlf", "ident", "filter",
+					 "eol", "text", NULL);
 		user_convert_tail = &user_convert;
 		git_config(read_convert_config, NULL);
 	}
 
-	if (!git_check_attr(path, NUM_CONV_ATTRS, ccheck)) {
+	if (!git_check_attr(path, check)) {
+		struct attr_check_item *ccheck = check->items;
 		ca->crlf_action = git_path_check_crlf(ccheck + 4);
 		if (ca->crlf_action == CRLF_UNDEFINED)
 			ca->crlf_action = git_path_check_crlf(ccheck + 0);
diff --git a/diff.c b/diff.c
index 051761b..a628ac3 100644
--- a/diff.c
+++ b/diff.c
@@ -2870,8 +2870,25 @@
 			s->should_free = 1;
 			return 0;
 		}
-		if (size_only)
+
+		/*
+		 * Even if the caller would be happy with getting
+		 * only the size, we cannot return early at this
+		 * point if the path requires us to run the content
+		 * conversion.
+		 */
+		if (size_only && !would_convert_to_git(s->path))
 			return 0;
+
+		/*
+		 * Note: this check uses xsize_t(st.st_size) that may
+		 * not be the true size of the blob after it goes
+		 * through convert_to_git().  This may not strictly be
+		 * correct, but the whole point of big_file_threshold
+		 * and is_binary check being that we want to avoid
+		 * opening the file and inspecting the contents, this
+		 * is probably fine.
+		 */
 		if ((flags & CHECK_BINARY) &&
 		    s->size > big_file_threshold && s->is_binary == -1) {
 			s->is_binary = 1;
diff --git a/dir.c b/dir.c
index 4541f9e..837ff96 100644
--- a/dir.c
+++ b/dir.c
@@ -9,6 +9,7 @@
  */
 #include "cache.h"
 #include "dir.h"
+#include "attr.h"
 #include "refs.h"
 #include "wildmatch.h"
 #include "pathspec.h"
@@ -134,7 +135,8 @@
 		       PATHSPEC_LITERAL |
 		       PATHSPEC_GLOB |
 		       PATHSPEC_ICASE |
-		       PATHSPEC_EXCLUDE);
+		       PATHSPEC_EXCLUDE |
+		       PATHSPEC_ATTR);
 
 	for (n = 0; n < pathspec->nr; n++) {
 		size_t i = 0, len = 0, item_len;
@@ -209,6 +211,36 @@
 #define DO_MATCH_DIRECTORY (1<<1)
 #define DO_MATCH_SUBMODULE (1<<2)
 
+static int match_attrs(const char *name, int namelen,
+		       const struct pathspec_item *item)
+{
+	int i;
+
+	git_check_attr(name, item->attr_check);
+	for (i = 0; i < item->attr_match_nr; i++) {
+		const char *value;
+		int matched;
+		enum attr_match_mode match_mode;
+
+		value = item->attr_check->items[i].value;
+		match_mode = item->attr_match[i].match_mode;
+
+		if (ATTR_TRUE(value))
+			matched = (match_mode == MATCH_SET);
+		else if (ATTR_FALSE(value))
+			matched = (match_mode == MATCH_UNSET);
+		else if (ATTR_UNSET(value))
+			matched = (match_mode == MATCH_UNSPECIFIED);
+		else
+			matched = (match_mode == MATCH_VALUE &&
+				   !strcmp(item->attr_match[i].value, value));
+		if (!matched)
+			return 0;
+	}
+
+	return 1;
+}
+
 /*
  * Does 'match' match the given name?
  * A match is found if
@@ -261,6 +293,9 @@
 	    strncmp(item->match, name - prefix, item->prefix))
 		return 0;
 
+	if (item->attr_match_nr && !match_attrs(name, namelen, item))
+		return 0;
+
 	/* If the match was just the prefix, we matched */
 	if (!*match)
 		return MATCHED_RECURSIVELY;
@@ -339,7 +374,8 @@
 		       PATHSPEC_LITERAL |
 		       PATHSPEC_GLOB |
 		       PATHSPEC_ICASE |
-		       PATHSPEC_EXCLUDE);
+		       PATHSPEC_EXCLUDE |
+		       PATHSPEC_ATTR);
 
 	if (!ps->nr) {
 		if (!ps->recursive ||
@@ -1361,7 +1397,8 @@
 		       PATHSPEC_LITERAL |
 		       PATHSPEC_GLOB |
 		       PATHSPEC_ICASE |
-		       PATHSPEC_EXCLUDE);
+		       PATHSPEC_EXCLUDE |
+		       PATHSPEC_ATTR);
 
 	for (i = 0; i < pathspec->nr; i++) {
 		const struct pathspec_item *item = &pathspec->items[i];
@@ -2730,8 +2767,8 @@
 {
 	struct strbuf file_name = STRBUF_INIT;
 	struct strbuf rel_path = STRBUF_INIT;
-	char *git_dir = real_pathdup(git_dir_);
-	char *work_tree = real_pathdup(work_tree_);
+	char *git_dir = real_pathdup(git_dir_, 1);
+	char *work_tree = real_pathdup(work_tree_, 1);
 
 	/* Update gitfile */
 	strbuf_addf(&file_name, "%s/.git", work_tree);
diff --git a/environment.c b/environment.c
index c07fb17..42dc310 100644
--- a/environment.c
+++ b/environment.c
@@ -259,7 +259,7 @@
 		return;
 	}
 	git_work_tree_initialized = 1;
-	work_tree = real_pathdup(new_work_tree);
+	work_tree = real_pathdup(new_work_tree, 1);
 }
 
 const char *get_git_work_tree(void)
diff --git a/ewah/ewah_io.c b/ewah/ewah_io.c
index 61f6a43..f732109 100644
--- a/ewah/ewah_io.c
+++ b/ewah/ewah_io.c
@@ -142,8 +142,8 @@
 	 * the endianness conversion in a separate pass to ensure
 	 * we're loading 8-byte aligned words.
 	 */
-	memcpy(self->buffer, ptr, self->buffer_size * sizeof(uint64_t));
-	ptr += self->buffer_size * sizeof(uint64_t);
+	memcpy(self->buffer, ptr, self->buffer_size * sizeof(eword_t));
+	ptr += self->buffer_size * sizeof(eword_t);
 
 	for (i = 0; i < self->buffer_size; ++i)
 		self->buffer[i] = ntohll(self->buffer[i]);
diff --git a/fast-import.c b/fast-import.c
index 64fe602..6c13472 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -1752,7 +1752,7 @@
 
 	if (is_null_sha1(b->sha1)) {
 		if (b->delete)
-			delete_ref(b->name, NULL, 0);
+			delete_ref(NULL, b->name, NULL, 0);
 		return 0;
 	}
 	if (read_ref(b->name, old_sha1))
diff --git a/fetch-pack.c b/fetch-pack.c
index 601f077..d07d85c 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -35,6 +35,7 @@
 #define COMMON_REF	(1U << 2)
 #define SEEN		(1U << 3)
 #define POPPED		(1U << 4)
+#define ALTERNATE	(1U << 5)
 
 static int marked;
 
@@ -67,6 +68,41 @@
 	fputc('\n', stderr);
 }
 
+struct alternate_object_cache {
+	struct object **items;
+	size_t nr, alloc;
+};
+
+static void cache_one_alternate(const char *refname,
+				const struct object_id *oid,
+				void *vcache)
+{
+	struct alternate_object_cache *cache = vcache;
+	struct object *obj = parse_object(oid->hash);
+
+	if (!obj || (obj->flags & ALTERNATE))
+		return;
+
+	obj->flags |= ALTERNATE;
+	ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
+	cache->items[cache->nr++] = obj;
+}
+
+static void for_each_cached_alternate(void (*cb)(struct object *))
+{
+	static int initialized;
+	static struct alternate_object_cache cache;
+	size_t i;
+
+	if (!initialized) {
+		for_each_alternate_ref(cache_one_alternate, &cache);
+		initialized = 1;
+	}
+
+	for (i = 0; i < cache.nr; i++)
+		cb(cache.items[i]);
+}
+
 static void rev_list_push(struct commit *commit, int mark)
 {
 	if (!(commit->object.flags & mark)) {
@@ -253,9 +289,9 @@
 		write_or_die(fd, buf->buf, buf->len);
 }
 
-static void insert_one_alternate_ref(const struct ref *ref, void *unused)
+static void insert_one_alternate_object(struct object *obj)
 {
-	rev_list_insert_ref(NULL, ref->old_oid.hash);
+	rev_list_insert_ref(NULL, obj->oid.hash);
 }
 
 #define INITIAL_FLUSH 16
@@ -298,7 +334,7 @@
 	marked = 1;
 
 	for_each_ref(rev_list_insert_ref_oid, NULL);
-	for_each_alternate_ref(insert_one_alternate_ref, NULL);
+	for_each_cached_alternate(insert_one_alternate_object);
 
 	fetching = 0;
 	for ( ; refs ; refs = refs->next) {
@@ -578,7 +614,7 @@
 					break; /* definitely do not have it */
 				else if (cmp == 0) {
 					keep = 1; /* definitely have it */
-					sought[i]->matched = 1;
+					sought[i]->match_status = REF_MATCHED;
 				}
 				i++;
 			}
@@ -598,30 +634,32 @@
 	}
 
 	/* Append unmatched requests to the list */
-	if ((allow_unadvertised_object_request &
-	    (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1))) {
-		for (i = 0; i < nr_sought; i++) {
-			unsigned char sha1[20];
+	for (i = 0; i < nr_sought; i++) {
+		unsigned char sha1[20];
 
-			ref = sought[i];
-			if (ref->matched)
-				continue;
-			if (get_sha1_hex(ref->name, sha1) ||
-			    ref->name[40] != '\0' ||
-			    hashcmp(sha1, ref->old_oid.hash))
-				continue;
+		ref = sought[i];
+		if (ref->match_status != REF_NOT_MATCHED)
+			continue;
+		if (get_sha1_hex(ref->name, sha1) ||
+		    ref->name[40] != '\0' ||
+		    hashcmp(sha1, ref->old_oid.hash))
+			continue;
 
-			ref->matched = 1;
+		if ((allow_unadvertised_object_request &
+		    (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1))) {
+			ref->match_status = REF_MATCHED;
 			*newtail = copy_ref(ref);
 			newtail = &(*newtail)->next;
+		} else {
+			ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 		}
 	}
 	*refs = newlist;
 }
 
-static void mark_alternate_complete(const struct ref *ref, void *unused)
+static void mark_alternate_complete(struct object *obj)
 {
-	mark_complete(ref->old_oid.hash);
+	mark_complete(obj->oid.hash);
 }
 
 static int everything_local(struct fetch_pack_args *args,
@@ -657,7 +695,7 @@
 
 	if (!args->deepen) {
 		for_each_ref(mark_complete_oid, NULL);
-		for_each_alternate_ref(mark_alternate_complete, NULL);
+		for_each_cached_alternate(mark_alternate_complete);
 		commit_list_sort_by_date(&complete);
 		if (cutoff)
 			mark_recent_complete_commits(args, cutoff);
@@ -1094,3 +1132,26 @@
 	clear_shallow_info(&si);
 	return ref_cpy;
 }
+
+int report_unmatched_refs(struct ref **sought, int nr_sought)
+{
+	int i, ret = 0;
+
+	for (i = 0; i < nr_sought; i++) {
+		if (!sought[i])
+			continue;
+		switch (sought[i]->match_status) {
+		case REF_MATCHED:
+			continue;
+		case REF_NOT_MATCHED:
+			error(_("no such remote ref %s"), sought[i]->name);
+			break;
+		case REF_UNADVERTISED_NOT_ALLOWED:
+			error(_("Server does not allow request for unadvertised object %s"),
+			      sought[i]->name);
+			break;
+		}
+		ret = 1;
+	}
+	return ret;
+}
diff --git a/fetch-pack.h b/fetch-pack.h
index c912e3d..a2d46e6 100644
--- a/fetch-pack.h
+++ b/fetch-pack.h
@@ -45,4 +45,10 @@
 		       struct sha1_array *shallow,
 		       char **pack_lockfile);
 
+/*
+ * Print an appropriate error message for each sought ref that wasn't
+ * matched.  Return 0 if all sought refs were matched, otherwise 1.
+ */
+int report_unmatched_refs(struct ref **sought, int nr_sought);
+
 #endif
diff --git a/git-add--interactive.perl b/git-add--interactive.perl
index 982593c..77b4ed5 100755
--- a/git-add--interactive.perl
+++ b/git-add--interactive.perl
@@ -92,7 +92,7 @@
 }
 
 # command line options
-my $cmd;
+my $patch_mode_only;
 my $patch_mode;
 my $patch_mode_revision;
 
@@ -275,20 +275,11 @@
 	my ($only) = @_;
 	my (%data, @return);
 	my ($add, $del, $adddel, $file);
-	my @tracked = ();
-
-	if (@ARGV) {
-		@tracked = map {
-			chomp $_;
-			unquote_path($_);
-		} run_cmd_pipe(qw(git ls-files --), @ARGV);
-		return if (!@tracked);
-	}
 
 	my $reference = get_diff_reference($patch_mode_revision);
 	for (run_cmd_pipe(qw(git diff-index --cached
 			     --numstat --summary), $reference,
-			     '--', @tracked)) {
+			     '--', @ARGV)) {
 		if (($add, $del, $file) =
 		    /^([-\d]+)	([-\d]+)	(.*)/) {
 			my ($change, $bin);
@@ -313,7 +304,7 @@
 		}
 	}
 
-	for (run_cmd_pipe(qw(git diff-files --numstat --summary --raw --), @tracked)) {
+	for (run_cmd_pipe(qw(git diff-files --numstat --summary --raw --), @ARGV)) {
 		if (($add, $del, $file) =
 		    /^([-\d]+)	([-\d]+)	(.*)/) {
 			$file = unquote_path($file);
@@ -1299,7 +1290,7 @@
 		}
 		return 0;
 	}
-	if ($patch_mode) {
+	if ($patch_mode_only) {
 		@them = @mods;
 	}
 	else {
@@ -1721,7 +1712,7 @@
 		die sprintf(__("invalid argument %s, expecting --"),
 			       $arg) unless $arg eq "--";
 		%patch_mode_flavour = %{$patch_modes{$patch_mode}};
-		$cmd = 1;
+		$patch_mode_only = 1;
 	}
 	elsif ($arg ne "--") {
 		die sprintf(__("invalid argument %s, expecting --"), $arg);
@@ -1758,7 +1749,7 @@
 
 process_args();
 refresh();
-if ($cmd) {
+if ($patch_mode_only) {
 	patch_update_cmd();
 }
 else {
diff --git a/git-compat-util.h b/git-compat-util.h
index ef6d560..e626851 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -639,11 +639,6 @@
 extern char *gitmkdtemp(char *);
 #endif
 
-#ifdef NO_MKSTEMPS
-#define mkstemps gitmkstemps
-extern int gitmkstemps(char *, int);
-#endif
-
 #ifdef NO_UNSETENV
 #define unsetenv gitunsetenv
 extern void gitunsetenv(const char *);
diff --git a/git-filter-branch.sh b/git-filter-branch.sh
index 86b2ff1..2b8cdba 100755
--- a/git-filter-branch.sh
+++ b/git-filter-branch.sh
@@ -46,6 +46,8 @@
 {
 	if test $# = 3 && test "$1" = $(git rev-parse "$3^{tree}"); then
 		map "$3"
+	elif test $# = 1 && test "$1" = 4b825dc642cb6eb9a060e54bf8d69288fbee4904; then
+		:
 	else
 		git commit-tree "$@"
 	fi
diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 4734094..2c9c016 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -1069,6 +1069,10 @@
 
 case "$action" in
 continue)
+	if test ! -d "$rewritten"
+	then
+		exec git rebase--helper ${force_rebase:+--no-ff} --continue
+	fi
 	# do we have anything to commit?
 	if git diff-index --cached --quiet HEAD --
 	then
@@ -1128,6 +1132,10 @@
 skip)
 	git rerere clear
 
+	if test ! -d "$rewritten"
+	then
+		exec git rebase--helper ${force_rebase:+--no-ff} --continue
+	fi
 	do_rest
 	return 0
 	;;
@@ -1314,6 +1322,11 @@
 test -d "$rewritten" || test -n "$force_rebase" || skip_unnecessary_picks
 
 checkout_onto
+if test -z "$rebase_root" && test ! -d "$rewritten"
+then
+	require_clean_work_tree "rebase"
+	exec git rebase--helper ${force_rebase:+--no-ff} --continue
+fi
 do_rest
 
 }
diff --git a/git-send-email.perl b/git-send-email.perl
index 068d60b..eea0a51 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -1563,7 +1563,7 @@
 	# Now parse the message body
 	while(<$fh>) {
 		$message .=  $_;
-		if (/^(Signed-off-by|Cc): (.*)$/i) {
+		if (/^(Signed-off-by|Cc): ([^>]*>?)/i) {
 			chomp;
 			my ($what, $c) = ($1, $2);
 			chomp $c;
diff --git a/git-stash.sh b/git-stash.sh
index 10c284d..9c70662 100755
--- a/git-stash.sh
+++ b/git-stash.sh
@@ -7,8 +7,11 @@
    or: $dashless drop [-q|--quiet] [<stash>]
    or: $dashless ( pop | apply ) [--index] [-q|--quiet] [<stash>]
    or: $dashless branch <branchname> [<stash>]
-   or: $dashless [save [--patch] [-k|--[no-]keep-index] [-q|--quiet]
-		       [-u|--include-untracked] [-a|--all] [<message>]]
+   or: $dashless save [--patch] [-k|--[no-]keep-index] [-q|--quiet]
+		      [-u|--include-untracked] [-a|--all] [<message>]
+   or: $dashless [push [--patch] [-k|--[no-]keep-index] [-q|--quiet]
+		       [-u|--include-untracked] [-a|--all] [-m <message>]
+		       [-- <pathspec>...]]
    or: $dashless clear"
 
 SUBDIRECTORY_OK=Yes
@@ -33,15 +36,15 @@
 fi
 
 no_changes () {
-	git diff-index --quiet --cached HEAD --ignore-submodules -- &&
-	git diff-files --quiet --ignore-submodules &&
+	git diff-index --quiet --cached HEAD --ignore-submodules -- "$@" &&
+	git diff-files --quiet --ignore-submodules -- "$@" &&
 	(test -z "$untracked" || test -z "$(untracked_files)")
 }
 
 untracked_files () {
 	excl_opt=--exclude-standard
 	test "$untracked" = "all" && excl_opt=
-	git ls-files -o -z $excl_opt
+	git ls-files -o -z $excl_opt -- "$@"
 }
 
 clear_stash () {
@@ -56,11 +59,29 @@
 }
 
 create_stash () {
-	stash_msg="$1"
-	untracked="$2"
+	stash_msg=
+	untracked=
+	while test $# != 0
+	do
+		case "$1" in
+		-m|--message)
+			shift
+			stash_msg=${1?"BUG: create_stash () -m requires an argument"}
+			;;
+		-u|--include-untracked)
+			shift
+			untracked=${1?"BUG: create_stash () -u requires an argument"}
+			;;
+		--)
+			shift
+			break
+			;;
+		esac
+		shift
+	done
 
 	git update-index -q --refresh
-	if no_changes
+	if no_changes "$@"
 	then
 		exit 0
 	fi
@@ -92,7 +113,7 @@
 		# Untracked files are stored by themselves in a parentless commit, for
 		# ease of unpacking later.
 		u_commit=$(
-			untracked_files | (
+			untracked_files "$@" | (
 				GIT_INDEX_FILE="$TMPindex" &&
 				export GIT_INDEX_FILE &&
 				rm -f "$TMPindex" &&
@@ -115,7 +136,7 @@
 			git read-tree --index-output="$TMPindex" -m $i_tree &&
 			GIT_INDEX_FILE="$TMPindex" &&
 			export GIT_INDEX_FILE &&
-			git diff-index --name-only -z HEAD -- >"$TMP-stagenames" &&
+			git diff-index --name-only -z HEAD -- "$@" >"$TMP-stagenames" &&
 			git update-index -z --add --remove --stdin <"$TMP-stagenames" &&
 			git write-tree &&
 			rm -f "$TMPindex"
@@ -129,7 +150,7 @@
 
 		# find out what the user wants
 		GIT_INDEX_FILE="$TMP-index" \
-			git add--interactive --patch=stash -- &&
+			git add--interactive --patch=stash -- "$@" &&
 
 		# state of the working tree
 		w_tree=$(GIT_INDEX_FILE="$TMP-index" git write-tree) ||
@@ -189,10 +210,11 @@
 	return $ret
 }
 
-save_stash () {
+push_stash () {
 	keep_index=
 	patch_mode=
 	untracked=
+	stash_msg=
 	while test $# != 0
 	do
 		case "$1" in
@@ -216,6 +238,11 @@
 		-a|--all)
 			untracked=all
 			;;
+		-m|--message)
+			shift
+			test -z ${1+x} && usage
+			stash_msg=$1
+			;;
 		--help)
 			show_help
 			;;
@@ -251,29 +278,38 @@
 		die "$(gettext "Can't use --patch and --include-untracked or --all at the same time")"
 	fi
 
-	stash_msg="$*"
+	test -n "$untracked" || git ls-files --error-unmatch -- "$@" >/dev/null || exit 1
 
 	git update-index -q --refresh
-	if no_changes
+	if no_changes "$@"
 	then
 		say "$(gettext "No local changes to save")"
 		exit 0
 	fi
+
 	git reflog exists $ref_stash ||
 		clear_stash || die "$(gettext "Cannot initialize stash")"
 
-	create_stash "$stash_msg" $untracked
+	create_stash -m "$stash_msg" -u "$untracked" -- "$@"
 	store_stash -m "$stash_msg" -q $w_commit ||
 	die "$(gettext "Cannot save the current status")"
 	say "$(eval_gettext "Saved working directory and index state \$stash_msg")"
 
 	if test -z "$patch_mode"
 	then
-		git reset --hard ${GIT_QUIET:+-q}
+		if test $# != 0
+		then
+			git reset ${GIT_QUIET:+-q} -- "$@"
+			git ls-files -z --modified -- "$@" |
+			git checkout-index -z --force --stdin
+			git clean --force ${GIT_QUIET:+-q} -d -- "$@"
+		else
+			git reset --hard ${GIT_QUIET:+-q}
+		fi
 		test "$untracked" = "all" && CLEAN_X_OPTION=-x || CLEAN_X_OPTION=
 		if test -n "$untracked"
 		then
-			git clean --force --quiet -d $CLEAN_X_OPTION
+			git clean --force --quiet -d $CLEAN_X_OPTION -- "$@"
 		fi
 
 		if test "$keep_index" = "t" && test -n "$i_tree"
@@ -291,6 +327,36 @@
 	fi
 }
 
+save_stash () {
+	push_options=
+	while test $# != 0
+	do
+		case "$1" in
+		--)
+			shift
+			break
+			;;
+		-*)
+			# pass all options through to push_stash
+			push_options="$push_options $1"
+			;;
+		*)
+			break
+			;;
+		esac
+		shift
+	done
+
+	stash_msg="$*"
+
+	if test -z "$stash_msg"
+	then
+		push_stash $push_options
+	else
+		push_stash $push_options -m "$stash_msg"
+	fi
+}
+
 have_stash () {
 	git rev-parse --verify --quiet $ref_stash >/dev/null
 }
@@ -590,18 +656,21 @@
 	}
 }
 
+test "$1" = "-p" && set "push" "$@"
+
 PARSE_CACHE='--not-parsed'
-# The default command is "save" if nothing but options are given
+# The default command is "push" if nothing but options are given
 seen_non_option=
 for opt
 do
 	case "$opt" in
+	--) break ;;
 	-*) ;;
 	*) seen_non_option=t; break ;;
 	esac
 done
 
-test -n "$seen_non_option" || set "save" "$@"
+test -n "$seen_non_option" || set "push" "$@"
 
 # Main command set
 case "$1" in
@@ -617,6 +686,10 @@
 	shift
 	save_stash "$@"
 	;;
+push)
+	shift
+	push_stash "$@"
+	;;
 apply)
 	shift
 	apply_stash "$@"
@@ -627,7 +700,7 @@
 	;;
 create)
 	shift
-	create_stash "$*" && echo "$w_commit"
+	create_stash -m "$*" && echo "$w_commit"
 	;;
 store)
 	shift
@@ -648,7 +721,7 @@
 *)
 	case $# in
 	0)
-		save_stash &&
+		push_stash &&
 		say "$(gettext "(To restore them type \"git stash apply\")")"
 		;;
 	*)
diff --git a/git-svn.perl b/git-svn.perl
index fa42364..d240418 100755
--- a/git-svn.perl
+++ b/git-svn.perl
@@ -1175,10 +1175,10 @@
 	::_req_svn();
 	require SVN::Client;
 
+	my ($config, $baton, undef) = Git::SVN::Ra::prepare_config_once();
 	my $ctx = SVN::Client->new(
-		config => SVN::Core::config_get_config(
-			$Git::SVN::Ra::config_dir
-		),
+		auth => $baton,
+		config => $config,
 		log_msg => sub {
 			${ $_[0] } = defined $_message
 				? $_message
diff --git a/git.c b/git.c
index c887272..33f52ac 100644
--- a/git.c
+++ b/git.c
@@ -473,6 +473,7 @@
 	{ "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
 	{ "push", cmd_push, RUN_SETUP },
 	{ "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
+	{ "rebase--helper", cmd_rebase__helper, RUN_SETUP | NEED_WORK_TREE },
 	{ "receive-pack", cmd_receive_pack },
 	{ "reflog", cmd_reflog, RUN_SETUP },
 	{ "remote", cmd_remote, RUN_SETUP },
diff --git a/hash.h b/hash.h
new file mode 100644
index 0000000..f0d9ddd
--- /dev/null
+++ b/hash.h
@@ -0,0 +1,14 @@
+#ifndef HASH_H
+#define HASH_H
+
+#if defined(SHA1_PPC)
+#include "ppc/sha1.h"
+#elif defined(SHA1_APPLE)
+#include <CommonCrypto/CommonDigest.h>
+#elif defined(SHA1_OPENSSL)
+#include <openssl/sha.h>
+#else /* SHA1_BLK */
+#include "block-sha1/sha1.h"
+#endif
+
+#endif
diff --git a/hex.c b/hex.c
index 845b01a..eab7b62 100644
--- a/hex.c
+++ b/hex.c
@@ -53,6 +53,14 @@
 	return get_sha1_hex(hex, oid->hash);
 }
 
+int parse_oid_hex(const char *hex, struct object_id *oid, const char **end)
+{
+	int ret = get_oid_hex(hex, oid);
+	if (!ret)
+		*end = hex + GIT_SHA1_HEXSZ;
+	return ret;
+}
+
 char *sha1_to_hex_r(char *buffer, const unsigned char *sha1)
 {
 	static const char hex[] = "0123456789abcdef";
diff --git a/http-walker.c b/http-walker.c
index b34b6ac..ee049cb 100644
--- a/http-walker.c
+++ b/http-walker.c
@@ -168,6 +168,11 @@
 	};
 	int i;
 
+	if (http_follow_config != HTTP_FOLLOW_ALWAYS) {
+		warning("alternate disabled by http.followRedirects: %s", url);
+		return 0;
+	}
+
 	for (i = 0; i < ARRAY_SIZE(protocols); i++) {
 		const char *end;
 		if (skip_prefix(url, protocols[i], &end) &&
@@ -296,13 +301,16 @@
 					okay = 1;
 				}
 			}
-			/* skip "objects\n" at end */
 			if (okay) {
 				struct strbuf target = STRBUF_INIT;
 				strbuf_add(&target, base, serverlen);
-				strbuf_add(&target, data + i, posn - i - 7);
-
-				if (is_alternate_allowed(target.buf)) {
+				strbuf_add(&target, data + i, posn - i);
+				if (!strbuf_strip_suffix(&target, "objects")) {
+					warning("ignoring alternate that does"
+						" not end in 'objects': %s",
+						target.buf);
+					strbuf_release(&target);
+				} else if (is_alternate_allowed(target.buf)) {
 					warning("adding alternate object store: %s",
 						target.buf);
 					newalt = xmalloc(sizeof(*newalt));
@@ -314,6 +322,8 @@
 					while (tail->next != NULL)
 						tail = tail->next;
 					tail->next = newalt;
+				} else {
+					strbuf_release(&target);
 				}
 			}
 		}
@@ -331,9 +341,6 @@
 	struct alternates_request alt_req;
 	struct walker_data *cdata = walker->data;
 
-	if (http_follow_config != HTTP_FOLLOW_ALWAYS)
-		return;
-
 	/*
 	 * If another request has already started fetching alternates,
 	 * wait for them to arrive and return to processing this request's
diff --git a/http.c b/http.c
index 90a1c0f..96d84bb 100644
--- a/http.c
+++ b/http.c
@@ -109,7 +109,7 @@
 struct credential http_auth = CREDENTIAL_INIT;
 static int http_proactive_auth;
 static const char *user_agent;
-static int curl_empty_auth;
+static int curl_empty_auth = -1;
 
 enum http_follow_config http_follow_config = HTTP_FOLLOW_INITIAL;
 
@@ -125,6 +125,14 @@
 static int ssl_cert_password_required;
 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 static unsigned long http_auth_methods = CURLAUTH_ANY;
+static int http_auth_methods_restricted;
+/* Modes for which empty_auth cannot actually help us. */
+static unsigned long empty_auth_useless =
+	CURLAUTH_BASIC
+#ifdef CURLAUTH_DIGEST_IE
+	| CURLAUTH_DIGEST_IE
+#endif
+	| CURLAUTH_DIGEST;
 #endif
 
 static struct curl_slist *pragma_header;
@@ -333,7 +341,10 @@
 		return git_config_string(&user_agent, var, value);
 
 	if (!strcmp("http.emptyauth", var)) {
-		curl_empty_auth = git_config_bool(var, value);
+		if (value && !strcmp("auto", value))
+			curl_empty_auth = -1;
+		else
+			curl_empty_auth = git_config_bool(var, value);
 		return 0;
 	}
 
@@ -382,10 +393,37 @@
 	return git_default_config(var, value, cb);
 }
 
+static int curl_empty_auth_enabled(void)
+{
+	if (curl_empty_auth >= 0)
+		return curl_empty_auth;
+
+#ifndef LIBCURL_CAN_HANDLE_AUTH_ANY
+	/*
+	 * Our libcurl is too old to do AUTH_ANY in the first place;
+	 * just default to turning the feature off.
+	 */
+#else
+	/*
+	 * In the automatic case, kick in the empty-auth
+	 * hack as long as we would potentially try some
+	 * method more exotic than "Basic" or "Digest".
+	 *
+	 * But only do this when this is our second or
+	 * subsequent request, as by then we know what
+	 * methods are available.
+	 */
+	if (http_auth_methods_restricted &&
+	    (http_auth_methods & ~empty_auth_useless))
+		return 1;
+#endif
+	return 0;
+}
+
 static void init_curl_http_auth(CURL *result)
 {
 	if (!http_auth.username || !*http_auth.username) {
-		if (curl_empty_auth)
+		if (curl_empty_auth_enabled())
 			curl_easy_setopt(result, CURLOPT_USERPWD, ":");
 		return;
 	}
@@ -1079,7 +1117,7 @@
 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
 #endif
-	if (http_auth.password || curl_empty_auth)
+	if (http_auth.password || curl_empty_auth_enabled())
 		init_curl_http_auth(slot->curl);
 
 	return slot;
@@ -1347,6 +1385,10 @@
 		} else {
 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 			http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
+			if (results->auth_avail) {
+				http_auth_methods &= results->auth_avail;
+				http_auth_methods_restricted = 1;
+			}
 #endif
 			return HTTP_REAUTH;
 		}
@@ -1727,6 +1769,9 @@
 {
 	int ret = http_request(url, result, target, options);
 
+	if (ret != HTTP_OK && ret != HTTP_REAUTH)
+		return ret;
+
 	if (options && options->effective_url && options->base_url) {
 		if (update_url_from_redirect(options->base_url,
 					     url, options->effective_url)) {
diff --git a/ident.c b/ident.c
index ac4ae02..c0364fe 100644
--- a/ident.c
+++ b/ident.c
@@ -153,7 +153,7 @@
 
 const char *ident_default_name(void)
 {
-	if (!git_default_name.len) {
+	if (!(ident_config_given & IDENT_NAME_GIVEN) && !git_default_name.len) {
 		copy_gecos(xgetpwuid_self(&default_name_is_bogus), &git_default_name);
 		strbuf_trim(&git_default_name);
 	}
@@ -162,7 +162,7 @@
 
 const char *ident_default_email(void)
 {
-	if (!git_default_email.len) {
+	if (!(ident_config_given & IDENT_MAIL_GIVEN) && !git_default_email.len) {
 		const char *email = getenv("EMAIL");
 
 		if (email && email[0]) {
@@ -203,6 +203,15 @@
 		c == '\'';
 }
 
+static int has_non_crud(const char *str)
+{
+	for (; *str; str++) {
+		if (!crud(*str))
+			return 1;
+	}
+	return 0;
+}
+
 /*
  * Copy over a string to the destination, but avoid special
  * characters ('\n', '<' and '>') and remove crud at the end
@@ -351,19 +360,32 @@
 	int want_date = !(flag & IDENT_NO_DATE);
 	int want_name = !(flag & IDENT_NO_NAME);
 
+	if (!email) {
+		if (strict && ident_use_config_only
+		    && !(ident_config_given & IDENT_MAIL_GIVEN)) {
+			fputs(_(env_hint), stderr);
+			die(_("no email was given and auto-detection is disabled"));
+		}
+		email = ident_default_email();
+		if (strict && default_email_is_bogus) {
+			fputs(_(env_hint), stderr);
+			die(_("unable to auto-detect email address (got '%s')"), email);
+		}
+	}
+
 	if (want_name) {
 		int using_default = 0;
 		if (!name) {
 			if (strict && ident_use_config_only
 			    && !(ident_config_given & IDENT_NAME_GIVEN)) {
 				fputs(_(env_hint), stderr);
-				die("no name was given and auto-detection is disabled");
+				die(_("no name was given and auto-detection is disabled"));
 			}
 			name = ident_default_name();
 			using_default = 1;
 			if (strict && default_name_is_bogus) {
 				fputs(_(env_hint), stderr);
-				die("unable to auto-detect name (got '%s')", name);
+				die(_("unable to auto-detect name (got '%s')"), name);
 			}
 		}
 		if (!*name) {
@@ -371,24 +393,13 @@
 			if (strict) {
 				if (using_default)
 					fputs(_(env_hint), stderr);
-				die("empty ident name (for <%s>) not allowed", email);
+				die(_("empty ident name (for <%s>) not allowed"), email);
 			}
 			pw = xgetpwuid_self(NULL);
 			name = pw->pw_name;
 		}
-	}
-
-	if (!email) {
-		if (strict && ident_use_config_only
-		    && !(ident_config_given & IDENT_MAIL_GIVEN)) {
-			fputs(_(env_hint), stderr);
-			die("no email was given and auto-detection is disabled");
-		}
-		email = ident_default_email();
-		if (strict && default_email_is_bogus) {
-			fputs(_(env_hint), stderr);
-			die("unable to auto-detect email address (got '%s')", email);
-		}
+		if (strict && !has_non_crud(name))
+			die(_("name consists only of disallowed characters: %s"), name);
 	}
 
 	strbuf_reset(&ident);
@@ -403,7 +414,7 @@
 		strbuf_addch(&ident, ' ');
 		if (date_str && date_str[0]) {
 			if (parse_date(date_str, &ident) < 0)
-				die("invalid date format: %s", date_str);
+				die(_("invalid date format: %s"), date_str);
 		}
 		else
 			strbuf_addstr(&ident, ident_default_date());
diff --git a/line-log.c b/line-log.c
index 65f3558..a23b910 100644
--- a/line-log.c
+++ b/line-log.c
@@ -43,9 +43,10 @@
 static void range_set_copy(struct range_set *dst, struct range_set *src)
 {
 	range_set_init(dst, src->nr);
-	memcpy(dst->ranges, src->ranges, src->nr*sizeof(struct range_set));
+	COPY_ARRAY(dst->ranges, src->ranges, src->nr);
 	dst->nr = src->nr;
 }
+
 static void range_set_move(struct range_set *dst, struct range_set *src)
 {
 	range_set_release(dst);
@@ -144,7 +145,7 @@
 static void range_set_union(struct range_set *out,
 			     struct range_set *a, struct range_set *b)
 {
-	int i = 0, j = 0, o = 0;
+	int i = 0, j = 0;
 	struct range *ra = a->ranges;
 	struct range *rb = b->ranges;
 	/* cannot make an alias of out->ranges: it may change during grow */
@@ -167,16 +168,15 @@
 			new = &rb[j++];
 		if (new->start == new->end)
 			; /* empty range */
-		else if (!o || out->ranges[o-1].end < new->start) {
+		else if (!out->nr || out->ranges[out->nr-1].end < new->start) {
 			range_set_grow(out, 1);
-			out->ranges[o].start = new->start;
-			out->ranges[o].end = new->end;
-			o++;
-		} else if (out->ranges[o-1].end < new->end) {
-			out->ranges[o-1].end = new->end;
+			out->ranges[out->nr].start = new->start;
+			out->ranges[out->nr].end = new->end;
+			out->nr++;
+		} else if (out->ranges[out->nr-1].end < new->end) {
+			out->ranges[out->nr-1].end = new->end;
 		}
 	}
-	out->nr = o;
 }
 
 /*
diff --git a/ll-merge.c b/ll-merge.c
index ad8be42..ac0d4a5 100644
--- a/ll-merge.c
+++ b/ll-merge.c
@@ -336,15 +336,6 @@
 	return &ll_merge_drv[LL_TEXT_MERGE];
 }
 
-static int git_path_check_merge(const char *path, struct git_attr_check check[2])
-{
-	if (!check[0].attr) {
-		check[0].attr = git_attr("merge");
-		check[1].attr = git_attr("conflict-marker-size");
-	}
-	return git_check_attr(path, 2, check);
-}
-
 static void normalize_file(mmfile_t *mm, const char *path)
 {
 	struct strbuf strbuf = STRBUF_INIT;
@@ -362,7 +353,7 @@
 	     mmfile_t *theirs, const char *their_label,
 	     const struct ll_merge_options *opts)
 {
-	static struct git_attr_check check[2];
+	static struct attr_check *check;
 	static const struct ll_merge_options default_opts;
 	const char *ll_driver_name = NULL;
 	int marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
@@ -376,10 +367,14 @@
 		normalize_file(ours, path);
 		normalize_file(theirs, path);
 	}
-	if (!git_path_check_merge(path, check)) {
-		ll_driver_name = check[0].value;
-		if (check[1].value) {
-			marker_size = atoi(check[1].value);
+
+	if (!check)
+		check = attr_check_initl("merge", "conflict-marker-size", NULL);
+
+	if (!git_check_attr(path, check)) {
+		ll_driver_name = check->items[0].value;
+		if (check->items[1].value) {
+			marker_size = atoi(check->items[1].value);
 			if (marker_size <= 0)
 				marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
 		}
@@ -398,13 +393,13 @@
 
 int ll_merge_marker_size(const char *path)
 {
-	static struct git_attr_check check;
+	static struct attr_check *check;
 	int marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
 
-	if (!check.attr)
-		check.attr = git_attr("conflict-marker-size");
-	if (!git_check_attr(path, 1, &check) && check.value) {
-		marker_size = atoi(check.value);
+	if (!check)
+		check = attr_check_initl("conflict-marker-size", NULL);
+	if (!git_check_attr(path, check) && check->items[0].value) {
+		marker_size = atoi(check->items[0].value);
 		if (marker_size <= 0)
 			marker_size = DEFAULT_CONFLICT_MARKER_SIZE;
 	}
diff --git a/log-tree.c b/log-tree.c
index 8c24157..4618dd0 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -332,35 +332,31 @@
 	strbuf_release(&subject);
 }
 
+void fmt_output_email_subject(struct strbuf *sb, struct rev_info *opt)
+{
+	if (opt->total > 0) {
+		strbuf_addf(sb, "Subject: [%s%s%0*d/%d] ",
+			    opt->subject_prefix,
+			    *opt->subject_prefix ? " " : "",
+			    digits_in_number(opt->total),
+			    opt->nr, opt->total);
+	} else if (opt->total == 0 && opt->subject_prefix && *opt->subject_prefix) {
+		strbuf_addf(sb, "Subject: [%s] ",
+			    opt->subject_prefix);
+	} else {
+		strbuf_addstr(sb, "Subject: ");
+	}
+}
+
 void log_write_email_headers(struct rev_info *opt, struct commit *commit,
-			     const char **subject_p,
 			     const char **extra_headers_p,
 			     int *need_8bit_cte_p)
 {
-	const char *subject = NULL;
 	const char *extra_headers = opt->extra_headers;
 	const char *name = oid_to_hex(opt->zero_commit ?
 				      &null_oid : &commit->object.oid);
 
 	*need_8bit_cte_p = 0; /* unknown */
-	if (opt->total > 0) {
-		static char buffer[64];
-		snprintf(buffer, sizeof(buffer),
-			 "Subject: [%s%s%0*d/%d] ",
-			 opt->subject_prefix,
-			 *opt->subject_prefix ? " " : "",
-			 digits_in_number(opt->total),
-			 opt->nr, opt->total);
-		subject = buffer;
-	} else if (opt->total == 0 && opt->subject_prefix && *opt->subject_prefix) {
-		static char buffer[256];
-		snprintf(buffer, sizeof(buffer),
-			 "Subject: [%s] ",
-			 opt->subject_prefix);
-		subject = buffer;
-	} else {
-		subject = "Subject: ";
-	}
 
 	fprintf(opt->diffopt.file, "From %s Mon Sep 17 00:00:00 2001\n", name);
 	graph_show_oneline(opt->graph);
@@ -417,7 +413,6 @@
 		opt->diffopt.stat_sep = buffer;
 		strbuf_release(&filename);
 	}
-	*subject_p = subject;
 	*extra_headers_p = extra_headers;
 }
 
@@ -602,8 +597,10 @@
 	 */
 
 	if (cmit_fmt_is_mail(opt->commit_format)) {
-		log_write_email_headers(opt, commit, &ctx.subject, &extra_headers,
+		log_write_email_headers(opt, commit, &extra_headers,
 					&ctx.need_8bit_cte);
+		ctx.rev = opt;
+		ctx.print_email_subject = 1;
 	} else if (opt->commit_format != CMIT_FMT_USERFORMAT) {
 		fputs(diff_get_color_opt(&opt->diffopt, DIFF_COMMIT), opt->diffopt.file);
 		if (opt->commit_format != CMIT_FMT_ONELINE)
diff --git a/log-tree.h b/log-tree.h
index c8116e6..48f11fb 100644
--- a/log-tree.h
+++ b/log-tree.h
@@ -22,7 +22,6 @@
 			     format_decorations_extended((strbuf), (commit), (color), " (", ", ", ")")
 void show_decorations(struct rev_info *opt, struct commit *commit);
 void log_write_email_headers(struct rev_info *opt, struct commit *commit,
-			     const char **subject_p,
 			     const char **extra_headers_p,
 			     int *need_8bit_cte_p);
 void load_ref_decorations(int flags);
@@ -30,5 +29,6 @@
 #define FORMAT_PATCH_NAME_MAX 64
 void fmt_output_commit(struct strbuf *, struct commit *, struct rev_info *);
 void fmt_output_subject(struct strbuf *, const char *subject, struct rev_info *);
+void fmt_output_email_subject(struct strbuf *, struct rev_info *);
 
 #endif
diff --git a/merge-recursive.c b/merge-recursive.c
index b7ff1ad..62decd5 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1061,16 +1061,20 @@
 }
 
 static int handle_change_delete(struct merge_options *o,
-				 const char *path,
+				 const char *path, const char *old_path,
 				 const struct object_id *o_oid, int o_mode,
-				 const struct object_id *a_oid, int a_mode,
-				 const struct object_id *b_oid, int b_mode,
+				 const struct object_id *changed_oid,
+				 int changed_mode,
+				 const char *change_branch,
+				 const char *delete_branch,
 				 const char *change, const char *change_past)
 {
-	char *renamed = NULL;
+	char *alt_path = NULL;
+	const char *update_path = path;
 	int ret = 0;
+
 	if (dir_in_way(path, !o->call_depth, 0)) {
-		renamed = unique_path(o, path, a_oid ? o->branch1 : o->branch2);
+		update_path = alt_path = unique_path(o, path, change_branch);
 	}
 
 	if (o->call_depth) {
@@ -1081,43 +1085,43 @@
 		 */
 		ret = remove_file_from_cache(path);
 		if (!ret)
-			ret = update_file(o, 0, o_oid, o_mode,
-					  renamed ? renamed : path);
-	} else if (!a_oid) {
-		if (!renamed) {
-			output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
-			       "and %s in %s. Version %s of %s left in tree."),
-			       change, path, o->branch1, change_past,
-			       o->branch2, o->branch2, path);
-			ret = update_file(o, 0, b_oid, b_mode, path);
-		} else {
-			output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
-			       "and %s in %s. Version %s of %s left in tree at %s."),
-			       change, path, o->branch1, change_past,
-			       o->branch2, o->branch2, path, renamed);
-			ret = update_file(o, 0, b_oid, b_mode, renamed);
-		}
+			ret = update_file(o, 0, o_oid, o_mode, update_path);
 	} else {
-		if (!renamed) {
-			output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
-			       "and %s in %s. Version %s of %s left in tree."),
-			       change, path, o->branch2, change_past,
-			       o->branch1, o->branch1, path);
+		if (!alt_path) {
+			if (!old_path) {
+				output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
+				       "and %s in %s. Version %s of %s left in tree."),
+				       change, path, delete_branch, change_past,
+				       change_branch, change_branch, path);
+			} else {
+				output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
+				       "and %s to %s in %s. Version %s of %s left in tree."),
+				       change, old_path, delete_branch, change_past, path,
+				       change_branch, change_branch, path);
+			}
 		} else {
-			output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
-			       "and %s in %s. Version %s of %s left in tree at %s."),
-			       change, path, o->branch2, change_past,
-			       o->branch1, o->branch1, path, renamed);
-			ret = update_file(o, 0, a_oid, a_mode, renamed);
+			if (!old_path) {
+				output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
+				       "and %s in %s. Version %s of %s left in tree at %s."),
+				       change, path, delete_branch, change_past,
+				       change_branch, change_branch, path, alt_path);
+			} else {
+				output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
+				       "and %s to %s in %s. Version %s of %s left in tree at %s."),
+				       change, old_path, delete_branch, change_past, path,
+				       change_branch, change_branch, path, alt_path);
+			}
 		}
 		/*
-		 * No need to call update_file() on path when !renamed, since
-		 * that would needlessly touch path.  We could call
-		 * update_file_flags() with update_cache=0 and update_wd=0,
-		 * but that's a no-op.
+		 * No need to call update_file() on path when change_branch ==
+		 * o->branch1 && !alt_path, since that would needlessly touch
+		 * path.  We could call update_file_flags() with update_cache=0
+		 * and update_wd=0, but that's a no-op.
 		 */
+		if (change_branch != o->branch1 || alt_path)
+			ret = update_file(o, 0, changed_oid, changed_mode, update_path);
 	}
-	free(renamed);
+	free(alt_path);
 
 	return ret;
 }
@@ -1125,28 +1129,17 @@
 static int conflict_rename_delete(struct merge_options *o,
 				   struct diff_filepair *pair,
 				   const char *rename_branch,
-				   const char *other_branch)
+				   const char *delete_branch)
 {
 	const struct diff_filespec *orig = pair->one;
 	const struct diff_filespec *dest = pair->two;
-	const struct object_id *a_oid = NULL;
-	const struct object_id *b_oid = NULL;
-	int a_mode = 0;
-	int b_mode = 0;
-
-	if (rename_branch == o->branch1) {
-		a_oid = &dest->oid;
-		a_mode = dest->mode;
-	} else {
-		b_oid = &dest->oid;
-		b_mode = dest->mode;
-	}
 
 	if (handle_change_delete(o,
 				 o->call_depth ? orig->path : dest->path,
+				 o->call_depth ? NULL : orig->path,
 				 &orig->oid, orig->mode,
-				 a_oid, a_mode,
-				 b_oid, b_mode,
+				 &dest->oid, dest->mode,
+				 rename_branch, delete_branch,
 				 _("rename"), _("renamed")))
 		return -1;
 
@@ -1662,11 +1655,27 @@
 				 struct object_id *a_oid, int a_mode,
 				 struct object_id *b_oid, int b_mode)
 {
+	const char *modify_branch, *delete_branch;
+	struct object_id *changed_oid;
+	int changed_mode;
+
+	if (a_oid) {
+		modify_branch = o->branch1;
+		delete_branch = o->branch2;
+		changed_oid = a_oid;
+		changed_mode = a_mode;
+	} else {
+		modify_branch = o->branch2;
+		delete_branch = o->branch1;
+		changed_oid = b_oid;
+		changed_mode = b_mode;
+	}
+
 	return handle_change_delete(o,
-				    path,
+				    path, NULL,
 				    o_oid, o_mode,
-				    a_oid, a_mode,
-				    b_oid, b_mode,
+				    changed_oid, changed_mode,
+				    modify_branch, delete_branch,
 				    _("modify"), _("modified"));
 }
 
diff --git a/object.h b/object.h
index 614a006..f52957d 100644
--- a/object.h
+++ b/object.h
@@ -29,7 +29,7 @@
 /*
  * object flag allocation:
  * revision.h:      0---------10                                26
- * fetch-pack.c:    0---4
+ * fetch-pack.c:    0---5
  * walker.c:        0-2
  * upload-pack.c:       4       11----------------19
  * builtin/blame.c:               12-13
diff --git a/oidset.c b/oidset.c
new file mode 100644
index 0000000..ac169f0
--- /dev/null
+++ b/oidset.c
@@ -0,0 +1,49 @@
+#include "cache.h"
+#include "oidset.h"
+
+struct oidset_entry {
+	struct hashmap_entry hash;
+	struct object_id oid;
+};
+
+static int oidset_hashcmp(const void *va, const void *vb,
+			  const void *vkey)
+{
+	const struct oidset_entry *a = va, *b = vb;
+	const struct object_id *key = vkey;
+	return oidcmp(&a->oid, key ? key : &b->oid);
+}
+
+int oidset_contains(const struct oidset *set, const struct object_id *oid)
+{
+	struct hashmap_entry key;
+
+	if (!set->map.cmpfn)
+		return 0;
+
+	hashmap_entry_init(&key, sha1hash(oid->hash));
+	return !!hashmap_get(&set->map, &key, oid);
+}
+
+int oidset_insert(struct oidset *set, const struct object_id *oid)
+{
+	struct oidset_entry *entry;
+
+	if (!set->map.cmpfn)
+		hashmap_init(&set->map, oidset_hashcmp, 0);
+
+	if (oidset_contains(set, oid))
+		return 1;
+
+	entry = xmalloc(sizeof(*entry));
+	hashmap_entry_init(&entry->hash, sha1hash(oid->hash));
+	oidcpy(&entry->oid, oid);
+
+	hashmap_add(&set->map, entry);
+	return 0;
+}
+
+void oidset_clear(struct oidset *set)
+{
+	hashmap_free(&set->map, 1);
+}
diff --git a/oidset.h b/oidset.h
new file mode 100644
index 0000000..b7eaab5
--- /dev/null
+++ b/oidset.h
@@ -0,0 +1,45 @@
+#ifndef OIDSET_H
+#define OIDSET_H
+
+/**
+ * This API is similar to sha1-array, in that it maintains a set of object ids
+ * in a memory-efficient way. The major differences are:
+ *
+ *   1. It uses a hash, so we can do online duplicate removal, rather than
+ *      sort-and-uniq at the end. This can reduce memory footprint if you have
+ *      a large list of oids with many duplicates.
+ *
+ *   2. The per-unique-oid memory footprint is slightly higher due to hash
+ *      table overhead.
+ */
+
+/**
+ * A single oidset; should be zero-initialized (or use OIDSET_INIT).
+ */
+struct oidset {
+	struct hashmap map;
+};
+
+#define OIDSET_INIT { { NULL } }
+
+/**
+ * Returns true iff `set` contains `oid`.
+ */
+int oidset_contains(const struct oidset *set, const struct object_id *oid);
+
+/**
+ * Insert the oid into the set; a copy is made, so "oid" does not need
+ * to persist after this function is called.
+ *
+ * Returns 1 if the oid was already in the set, 0 otherwise. This can be used
+ * to perform an efficient check-and-add.
+ */
+int oidset_insert(struct oidset *set, const struct object_id *oid);
+
+/**
+ * Remove all entries from the oidset, freeing any resources associated with
+ * it.
+ */
+void oidset_clear(struct oidset *set);
+
+#endif /* OIDSET_H */
diff --git a/pack-objects.h b/pack-objects.h
index cc9b9a9..03f1191 100644
--- a/pack-objects.h
+++ b/pack-objects.h
@@ -30,12 +30,16 @@
 
 	/*
 	 * State flags for depth-first search used for analyzing delta cycles.
+	 *
+	 * The depth is measured in delta-links to the base (so if A is a delta
+	 * against B, then A has a depth of 1, and B a depth of 0).
 	 */
 	enum {
 		DFS_NONE = 0,
 		DFS_ACTIVE,
 		DFS_DONE
 	} dfs_state;
+	int depth;
 };
 
 struct packing_data {
diff --git a/pathspec.c b/pathspec.c
index 7ababb3..303efda 100644
--- a/pathspec.c
+++ b/pathspec.c
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "dir.h"
 #include "pathspec.h"
+#include "attr.h"
 
 /*
  * Finds which of the given pathspecs match items in the index.
@@ -72,6 +73,7 @@
 	{ PATHSPEC_GLOB,    '\0', "glob" },
 	{ PATHSPEC_ICASE,   '\0', "icase" },
 	{ PATHSPEC_EXCLUDE,  '!', "exclude" },
+	{ PATHSPEC_ATTR,    '\0', "attr" },
 };
 
 static void prefix_magic(struct strbuf *sb, int prefixlen, unsigned magic)
@@ -87,6 +89,116 @@
 	strbuf_addf(sb, ",prefix:%d)", prefixlen);
 }
 
+static size_t strcspn_escaped(const char *s, const char *stop)
+{
+	const char *i;
+
+	for (i = s; *i; i++) {
+		/* skip the escaped character */
+		if (i[0] == '\\' && i[1]) {
+			i++;
+			continue;
+		}
+
+		if (strchr(stop, *i))
+			break;
+	}
+	return i - s;
+}
+
+static inline int invalid_value_char(const char ch)
+{
+	if (isalnum(ch) || strchr(",-_", ch))
+		return 0;
+	return -1;
+}
+
+static char *attr_value_unescape(const char *value)
+{
+	const char *src;
+	char *dst, *ret;
+
+	ret = xmallocz(strlen(value));
+	for (src = value, dst = ret; *src; src++, dst++) {
+		if (*src == '\\') {
+			if (!src[1])
+				die(_("Escape character '\\' not allowed as "
+				      "last character in attr value"));
+			src++;
+		}
+		if (invalid_value_char(*src))
+			die("cannot use '%c' for value matching", *src);
+		*dst = *src;
+	}
+	*dst = '\0';
+	return ret;
+}
+
+static void parse_pathspec_attr_match(struct pathspec_item *item, const char *value)
+{
+	struct string_list_item *si;
+	struct string_list list = STRING_LIST_INIT_DUP;
+
+	if (item->attr_check || item->attr_match)
+		die(_("Only one 'attr:' specification is allowed."));
+
+	if (!value || !*value)
+		die(_("attr spec must not be empty"));
+
+	string_list_split(&list, value, ' ', -1);
+	string_list_remove_empty_items(&list, 0);
+
+	item->attr_check = attr_check_alloc();
+	item->attr_match = xcalloc(list.nr, sizeof(struct attr_match));
+
+	for_each_string_list_item(si, &list) {
+		size_t attr_len;
+		char *attr_name;
+		const struct git_attr *a;
+
+		int j = item->attr_match_nr++;
+		const char *attr = si->string;
+		struct attr_match *am = &item->attr_match[j];
+
+		switch (*attr) {
+		case '!':
+			am->match_mode = MATCH_UNSPECIFIED;
+			attr++;
+			attr_len = strlen(attr);
+			break;
+		case '-':
+			am->match_mode = MATCH_UNSET;
+			attr++;
+			attr_len = strlen(attr);
+			break;
+		default:
+			attr_len = strcspn(attr, "=");
+			if (attr[attr_len] != '=')
+				am->match_mode = MATCH_SET;
+			else {
+				const char *v = &attr[attr_len + 1];
+				am->match_mode = MATCH_VALUE;
+				am->value = attr_value_unescape(v);
+			}
+			break;
+		}
+
+		attr_name = xmemdupz(attr, attr_len);
+		a = git_attr(attr_name);
+		if (!a)
+			die(_("invalid attribute name %s"), attr_name);
+
+		attr_check_append(item->attr_check, a);
+
+		free(attr_name);
+	}
+
+	if (item->attr_check->nr != item->attr_match_nr)
+		die("BUG: should have same number of entries");
+
+	string_list_clear(&list, 0);
+}
+
 static inline int get_literal_global(void)
 {
 	static int literal = -1;
@@ -164,13 +276,14 @@
  * returns the position in 'elem' after all magic has been parsed
  */
 static const char *parse_long_magic(unsigned *magic, int *prefix_len,
+				    struct pathspec_item *item,
 				    const char *elem)
 {
 	const char *pos;
 	const char *nextat;
 
 	for (pos = elem + 2; *pos && *pos != ')'; pos = nextat) {
-		size_t len = strcspn(pos, ",)");
+		size_t len = strcspn_escaped(pos, ",)");
 		int i;
 
 		if (pos[len] == ',')
@@ -189,6 +302,14 @@
 			continue;
 		}
 
+		if (starts_with(pos, "attr:")) {
+			char *attr_body = xmemdupz(pos + 5, len - 5);
+			parse_pathspec_attr_match(item, attr_body);
+			*magic |= PATHSPEC_ATTR;
+			free(attr_body);
+			continue;
+		}
+
 		for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++) {
 			if (strlen(pathspec_magic[i].name) == len &&
 			    !strncmp(pathspec_magic[i].name, pos, len)) {
@@ -224,6 +345,12 @@
 		char ch = *pos;
 		int i;
 
+		/* Special case alias for '!' */
+		if (ch == '^') {
+			*magic |= PATHSPEC_EXCLUDE;
+			continue;
+		}
+
 		if (!is_pathspec_magic(ch))
 			break;
 
@@ -246,13 +373,14 @@
 }
 
 static const char *parse_element_magic(unsigned *magic, int *prefix_len,
+				       struct pathspec_item *item,
 				       const char *elem)
 {
 	if (elem[0] != ':' || get_literal_global())
 		return elem; /* nothing to do */
 	else if (elem[1] == '(')
 		/* longhand */
-		return parse_long_magic(magic, prefix_len, elem);
+		return parse_long_magic(magic, prefix_len, item, elem);
 	else
 		/* shorthand */
 		return parse_short_magic(magic, elem);
@@ -329,12 +457,17 @@
 	char *match;
 	int pathspec_prefix = -1;
 
+	item->attr_check = NULL;
+	item->attr_match = NULL;
+	item->attr_match_nr = 0;
+
 	/* PATHSPEC_LITERAL_PATH ignores magic */
 	if (flags & PATHSPEC_LITERAL_PATH) {
 		magic = PATHSPEC_LITERAL;
 	} else {
 		copyfrom = parse_element_magic(&element_magic,
 					       &pathspec_prefix,
+					       item,
 					       elt);
 		magic |= element_magic;
 		magic |= get_global_magic(element_magic);
@@ -516,7 +649,7 @@
 	}
 
 	pathspec->nr = n;
-	ALLOC_ARRAY(pathspec->items, n);
+	ALLOC_ARRAY(pathspec->items, n + 1);
 	item = pathspec->items;
 	prefixlen = prefix ? strlen(prefix) : 0;
 
@@ -540,10 +673,15 @@
 		pathspec->magic |= item[i].magic;
 	}
 
-	if (nr_exclude == n)
-		die(_("There is nothing to exclude from by :(exclude) patterns.\n"
-		      "Perhaps you forgot to add either ':/' or '.' ?"));
-
+	/*
+	 * If everything is an exclude pattern, add one positive pattern
+	 * that matches everyting. We allocated an extra one for this.
+	 */
+	if (nr_exclude == n) {
+		int plen = (!(flags & PATHSPEC_PREFER_CWD)) ? 0 : prefixlen;
+		init_pathspec_item(item + n, 0, prefix, plen, "");
+		pathspec->nr++;
+	}
 
 	if (pathspec->magic & PATHSPEC_MAXDEPTH) {
 		if (flags & PATHSPEC_KEEP_ORDER)
@@ -554,26 +692,46 @@
 
 void copy_pathspec(struct pathspec *dst, const struct pathspec *src)
 {
-	int i;
+	int i, j;
 
 	*dst = *src;
 	ALLOC_ARRAY(dst->items, dst->nr);
 	COPY_ARRAY(dst->items, src->items, dst->nr);
 
 	for (i = 0; i < dst->nr; i++) {
-		dst->items[i].match = xstrdup(src->items[i].match);
-		dst->items[i].original = xstrdup(src->items[i].original);
+		struct pathspec_item *d = &dst->items[i];
+		struct pathspec_item *s = &src->items[i];
+
+		d->match = xstrdup(s->match);
+		d->original = xstrdup(s->original);
+
+		ALLOC_ARRAY(d->attr_match, d->attr_match_nr);
+		COPY_ARRAY(d->attr_match, s->attr_match, d->attr_match_nr);
+		for (j = 0; j < d->attr_match_nr; j++) {
+			const char *value = s->attr_match[j].value;
+			d->attr_match[j].value = xstrdup_or_null(value);
+		}
+
+		d->attr_check = attr_check_dup(s->attr_check);
 	}
 }
 
 void clear_pathspec(struct pathspec *pathspec)
 {
-	int i;
+	int i, j;
 
 	for (i = 0; i < pathspec->nr; i++) {
 		free(pathspec->items[i].match);
 		free(pathspec->items[i].original);
+
+		for (j = 0; j < pathspec->items[j].attr_match_nr; j++)
+			free(pathspec->items[i].attr_match[j].value);
+		free(pathspec->items[i].attr_match);
+
+		if (pathspec->items[i].attr_check)
+			attr_check_free(pathspec->items[i].attr_check);
 	}
+
 	free(pathspec->items);
 	pathspec->items = NULL;
 	pathspec->nr = 0;
diff --git a/pathspec.h b/pathspec.h
index 49fd823..55e9769 100644
--- a/pathspec.h
+++ b/pathspec.h
@@ -8,13 +8,15 @@
 #define PATHSPEC_GLOB		(1<<3)
 #define PATHSPEC_ICASE		(1<<4)
 #define PATHSPEC_EXCLUDE	(1<<5)
+#define PATHSPEC_ATTR		(1<<6)
 #define PATHSPEC_ALL_MAGIC	  \
 	(PATHSPEC_FROMTOP	| \
 	 PATHSPEC_MAXDEPTH	| \
 	 PATHSPEC_LITERAL	| \
 	 PATHSPEC_GLOB		| \
 	 PATHSPEC_ICASE		| \
-	 PATHSPEC_EXCLUDE)
+	 PATHSPEC_EXCLUDE	| \
+	 PATHSPEC_ATTR)
 
 #define PATHSPEC_ONESTAR 1	/* the pathspec pattern satisfies GFNM_ONESTAR */
 
@@ -31,6 +33,17 @@
 		int len, prefix;
 		int nowildcard_len;
 		int flags;
+		int attr_match_nr;
+		struct attr_match {
+			char *value;
+			enum attr_match_mode {
+				MATCH_SET,
+				MATCH_UNSET,
+				MATCH_VALUE,
+				MATCH_UNSPECIFIED
+			} match_mode;
+		} *attr_match;
+		struct attr_check *attr_check;
 	} *items;
 };
 
diff --git a/preload-index.c b/preload-index.c
index c1fe3a3..70a4c80 100644
--- a/preload-index.c
+++ b/preload-index.c
@@ -53,6 +53,8 @@
 			continue;
 		if (ce_uptodate(ce))
 			continue;
+		if (ce_skip_worktree(ce))
+			continue;
 		if (!ce_path_match(ce, &p->pathspec, NULL))
 			continue;
 		if (threaded_has_symlink_leading_path(&cache, ce->name, ce_namelen(ce)))
diff --git a/pretty.c b/pretty.c
index 5e68383..d0f86f5 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1607,8 +1607,9 @@
 				pp->preserve_subject ? "\n" : " ");
 
 	strbuf_grow(sb, title.len + 1024);
-	if (pp->subject) {
-		strbuf_addstr(sb, pp->subject);
+	if (pp->print_email_subject) {
+		if (pp->rev)
+			fmt_output_email_subject(sb, pp->rev);
 		if (needs_rfc2047_encoding(title.buf, title.len, RFC2047_SUBJECT))
 			add_rfc2047(sb, title.buf, title.len,
 						encoding, RFC2047_SUBJECT);
@@ -1818,7 +1819,7 @@
 	}
 
 	pp_header(pp, encoding, commit, &msg, sb);
-	if (pp->fmt != CMIT_FMT_ONELINE && !pp->subject) {
+	if (pp->fmt != CMIT_FMT_ONELINE && !pp->print_email_subject) {
 		strbuf_addch(sb, '\n');
 	}
 
diff --git a/progress.c b/progress.c
index 76a88c5..29378ca 100644
--- a/progress.c
+++ b/progress.c
@@ -243,21 +243,18 @@
 	*p_progress = NULL;
 	if (progress->last_value != -1) {
 		/* Force the last update */
-		char buf[128], *bufp;
-		size_t len = strlen(msg) + 5;
+		char *buf;
 		struct throughput *tp = progress->throughput;
 
-		bufp = (len < sizeof(buf)) ? buf : xmallocz(len);
 		if (tp) {
 			unsigned int rate = !tp->avg_misecs ? 0 :
 					tp->avg_bytes / tp->avg_misecs;
 			throughput_string(&tp->display, tp->curr_total, rate);
 		}
 		progress_update = 1;
-		xsnprintf(bufp, len + 1, ", %s.\n", msg);
-		display(progress, progress->last_value, bufp);
-		if (buf != bufp)
-			free(bufp);
+		buf = xstrfmt(", %s.\n", msg);
+		display(progress, progress->last_value, buf);
+		free(buf);
 	}
 	clear_progress_signal();
 	if (progress->throughput)
diff --git a/reachable.c b/reachable.c
index d0199ca..a8a979b 100644
--- a/reachable.c
+++ b/reachable.c
@@ -58,7 +58,7 @@
 	unsigned long timestamp;
 };
 
-static void add_recent_object(const unsigned char *sha1,
+static void add_recent_object(const struct object_id *oid,
 			      unsigned long mtime,
 			      struct recent_data *data)
 {
@@ -75,37 +75,37 @@
 	 * later processing, and the revision machinery expects
 	 * commits and tags to have been parsed.
 	 */
-	type = sha1_object_info(sha1, NULL);
+	type = sha1_object_info(oid->hash, NULL);
 	if (type < 0)
-		die("unable to get object info for %s", sha1_to_hex(sha1));
+		die("unable to get object info for %s", oid_to_hex(oid));
 
 	switch (type) {
 	case OBJ_TAG:
 	case OBJ_COMMIT:
-		obj = parse_object_or_die(sha1, NULL);
+		obj = parse_object_or_die(oid->hash, NULL);
 		break;
 	case OBJ_TREE:
-		obj = (struct object *)lookup_tree(sha1);
+		obj = (struct object *)lookup_tree(oid->hash);
 		break;
 	case OBJ_BLOB:
-		obj = (struct object *)lookup_blob(sha1);
+		obj = (struct object *)lookup_blob(oid->hash);
 		break;
 	default:
 		die("unknown object type for %s: %s",
-		    sha1_to_hex(sha1), typename(type));
+		    oid_to_hex(oid), typename(type));
 	}
 
 	if (!obj)
-		die("unable to lookup %s", sha1_to_hex(sha1));
+		die("unable to lookup %s", oid_to_hex(oid));
 
 	add_pending_object(data->revs, obj, "");
 }
 
-static int add_recent_loose(const unsigned char *sha1,
+static int add_recent_loose(const struct object_id *oid,
 			    const char *path, void *data)
 {
 	struct stat st;
-	struct object *obj = lookup_object(sha1);
+	struct object *obj = lookup_object(oid->hash);
 
 	if (obj && obj->flags & SEEN)
 		return 0;
@@ -119,22 +119,22 @@
 		 */
 		if (errno == ENOENT)
 			return 0;
-		return error_errno("unable to stat %s", sha1_to_hex(sha1));
+		return error_errno("unable to stat %s", oid_to_hex(oid));
 	}
 
-	add_recent_object(sha1, st.st_mtime, data);
+	add_recent_object(oid, st.st_mtime, data);
 	return 0;
 }
 
-static int add_recent_packed(const unsigned char *sha1,
+static int add_recent_packed(const struct object_id *oid,
 			     struct packed_git *p, uint32_t pos,
 			     void *data)
 {
-	struct object *obj = lookup_object(sha1);
+	struct object *obj = lookup_object(oid->hash);
 
 	if (obj && obj->flags & SEEN)
 		return 0;
-	add_recent_object(sha1, p->mtime, data);
+	add_recent_object(oid, p->mtime, data);
 	return 0;
 }
 
diff --git a/read-cache.c b/read-cache.c
index 9054369..e447751 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1558,10 +1558,27 @@
 	}
 }
 
+static void tweak_split_index(struct index_state *istate)
+{
+	switch (git_config_get_split_index()) {
+	case -1: /* unset: do nothing */
+		break;
+	case 0: /* false */
+		remove_split_index(istate);
+		break;
+	case 1: /* true */
+		add_split_index(istate);
+		break;
+	default: /* unknown value: do nothing */
+		break;
+	}
+}
+
 static void post_read_index_from(struct index_state *istate)
 {
 	check_ce_order(istate);
 	tweak_untracked_cache(istate);
+	tweak_split_index(istate);
 }
 
 /* remember to discard_cache() before reading a different cache! */
@@ -1657,10 +1674,25 @@
 	die("index file corrupt");
 }
 
+/*
+ * Signal that the shared index is used by updating its mtime.
+ *
+ * This way, shared index can be removed if they have not been used
+ * for some time.
+ */
+static void freshen_shared_index(char *base_sha1_hex, int warn)
+{
+	const char *shared_index = git_path("sharedindex.%s", base_sha1_hex);
+	if (!check_and_freshen_file(shared_index, 1) && warn)
+		warning("could not freshen shared index '%s'", shared_index);
+}
+
 int read_index_from(struct index_state *istate, const char *path)
 {
 	struct split_index *split_index;
 	int ret;
+	char *base_sha1_hex;
+	const char *base_path;
 
 	/* istate->initialized covers both .git/index and .git/sharedindex.xxx */
 	if (istate->initialized)
@@ -1678,15 +1710,16 @@
 		discard_index(split_index->base);
 	else
 		split_index->base = xcalloc(1, sizeof(*split_index->base));
-	ret = do_read_index(split_index->base,
-			    git_path("sharedindex.%s",
-				     sha1_to_hex(split_index->base_sha1)), 1);
+
+	base_sha1_hex = sha1_to_hex(split_index->base_sha1);
+	base_path = git_path("sharedindex.%s", base_sha1_hex);
+	ret = do_read_index(split_index->base, base_path, 1);
 	if (hashcmp(split_index->base_sha1, split_index->base->sha1))
 		die("broken index, expect %s in %s, got %s",
-		    sha1_to_hex(split_index->base_sha1),
-		    git_path("sharedindex.%s",
-			     sha1_to_hex(split_index->base_sha1)),
+		    base_sha1_hex, base_path,
 		    sha1_to_hex(split_index->base->sha1));
+
+	freshen_shared_index(base_sha1_hex, 0);
 	merge_base_index(istate);
 	post_read_index_from(istate);
 	return ret;
@@ -2169,6 +2202,65 @@
 	return ret;
 }
 
+static const char *shared_index_expire = "2.weeks.ago";
+
+static unsigned long get_shared_index_expire_date(void)
+{
+	static unsigned long shared_index_expire_date;
+	static int shared_index_expire_date_prepared;
+
+	if (!shared_index_expire_date_prepared) {
+		git_config_get_expiry("splitindex.sharedindexexpire",
+				      &shared_index_expire);
+		shared_index_expire_date = approxidate(shared_index_expire);
+		shared_index_expire_date_prepared = 1;
+	}
+
+	return shared_index_expire_date;
+}
+
+static int should_delete_shared_index(const char *shared_index_path)
+{
+	struct stat st;
+	unsigned long expiration;
+
+	/* Check timestamp */
+	expiration = get_shared_index_expire_date();
+	if (!expiration)
+		return 0;
+	if (stat(shared_index_path, &st))
+		return error_errno(_("could not stat '%s"), shared_index_path);
+	if (st.st_mtime > expiration)
+		return 0;
+
+	return 1;
+}
+
+static int clean_shared_index_files(const char *current_hex)
+{
+	struct dirent *de;
+	DIR *dir = opendir(get_git_dir());
+
+	if (!dir)
+		return error_errno(_("unable to open git dir: %s"), get_git_dir());
+
+	while ((de = readdir(dir)) != NULL) {
+		const char *sha1_hex;
+		const char *shared_index_path;
+		if (!skip_prefix(de->d_name, "sharedindex.", &sha1_hex))
+			continue;
+		if (!strcmp(sha1_hex, current_hex))
+			continue;
+		shared_index_path = git_path("%s", de->d_name);
+		if (should_delete_shared_index(shared_index_path) > 0 &&
+		    unlink(shared_index_path))
+			warning_errno(_("unable to unlink: %s"), shared_index_path);
+	}
+	closedir(dir);
+
+	return 0;
+}
+
 static struct tempfile temporary_sharedindex;
 
 static int write_shared_index(struct index_state *istate,
@@ -2190,14 +2282,48 @@
 	}
 	ret = rename_tempfile(&temporary_sharedindex,
 			      git_path("sharedindex.%s", sha1_to_hex(si->base->sha1)));
-	if (!ret)
+	if (!ret) {
 		hashcpy(si->base_sha1, si->base->sha1);
+		clean_shared_index_files(sha1_to_hex(si->base->sha1));
+	}
+
 	return ret;
 }
 
+static const int default_max_percent_split_change = 20;
+
+static int too_many_not_shared_entries(struct index_state *istate)
+{
+	int i, not_shared = 0;
+	int max_split = git_config_get_max_percent_split_change();
+
+	switch (max_split) {
+	case -1:
+		/* not or badly configured: use the default value */
+		max_split = default_max_percent_split_change;
+		break;
+	case 0:
+		return 1; /* 0% means always write a new shared index */
+	case 100:
+		return 0; /* 100% means never write a new shared index */
+	default:
+		break; /* just use the configured value */
+	}
+
+	/* Count not shared entries */
+	for (i = 0; i < istate->cache_nr; i++) {
+		struct cache_entry *ce = istate->cache[i];
+		if (!ce->index)
+			not_shared++;
+	}
+
+	return (int64_t)istate->cache_nr * max_split < (int64_t)not_shared * 100;
+}
+
 int write_locked_index(struct index_state *istate, struct lock_file *lock,
 		       unsigned flags)
 {
+	int new_shared_index, ret;
 	struct split_index *si = istate->split_index;
 
 	if (!si || alternate_index_output ||
@@ -2212,13 +2338,24 @@
 		if ((v & 15) < 6)
 			istate->cache_changed |= SPLIT_INDEX_ORDERED;
 	}
-	if (istate->cache_changed & SPLIT_INDEX_ORDERED) {
-		int ret = write_shared_index(istate, lock, flags);
+	if (too_many_not_shared_entries(istate))
+		istate->cache_changed |= SPLIT_INDEX_ORDERED;
+
+	new_shared_index = istate->cache_changed & SPLIT_INDEX_ORDERED;
+
+	if (new_shared_index) {
+		ret = write_shared_index(istate, lock, flags);
 		if (ret)
 			return ret;
 	}
 
-	return write_split_index(istate, lock, flags);
+	ret = write_split_index(istate, lock, flags);
+
+	/* Freshen the shared index only if the split-index was written */
+	if (!ret && !new_shared_index)
+		freshen_shared_index(sha1_to_hex(si->base_sha1), 1);
+
+	return ret;
 }
 
 /*
diff --git a/ref-filter.c b/ref-filter.c
index 3820b21..9c82b5b 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -14,14 +14,51 @@
 #include "git-compat-util.h"
 #include "version.h"
 #include "trailer.h"
+#include "wt-status.h"
+#include "commit-slab.h"
+
+static struct ref_msg {
+	const char *gone;
+	const char *ahead;
+	const char *behind;
+	const char *ahead_behind;
+} msgs = {
+	 /* Untranslated plumbing messages: */
+	"gone",
+	"ahead %d",
+	"behind %d",
+	"ahead %d, behind %d"
+};
+
+void setup_ref_filter_porcelain_msg(void)
+{
+	msgs.gone = _("gone");
+	msgs.ahead = _("ahead %d");
+	msgs.behind = _("behind %d");
+	msgs.ahead_behind = _("ahead %d, behind %d");
+}
 
 typedef enum { FIELD_STR, FIELD_ULONG, FIELD_TIME } cmp_type;
+typedef enum { COMPARE_EQUAL, COMPARE_UNEQUAL, COMPARE_NONE } cmp_status;
 
 struct align {
 	align_type position;
 	unsigned int width;
 };
 
+struct if_then_else {
+	cmp_status cmp_status;
+	const char *str;
+	unsigned int then_atom_seen : 1,
+		else_atom_seen : 1,
+		condition_satisfied : 1;
+};
+
+struct refname_atom {
+	enum { R_NORMAL, R_SHORT, R_LSTRIP, R_RSTRIP } option;
+	int lstrip, rstrip;
+};
+
 /*
  * An atom is a valid field atom listed below, possibly prefixed with
  * a "*" to denote deref_tag().
@@ -38,13 +75,24 @@
 	union {
 		char color[COLOR_MAXLEN];
 		struct align align;
-		enum { RR_NORMAL, RR_SHORTEN, RR_TRACK, RR_TRACKSHORT }
-			remote_ref;
+		struct {
+			enum { RR_REF, RR_TRACK, RR_TRACKSHORT } option;
+			struct refname_atom refname;
+			unsigned int nobracket : 1;
+		} remote_ref;
 		struct {
 			enum { C_BARE, C_BODY, C_BODY_DEP, C_LINES, C_SIG, C_SUB, C_TRAILERS } option;
 			unsigned int nlines;
 		} contents;
-		enum { O_FULL, O_SHORT } objectname;
+		struct {
+			cmp_status cmp_status;
+			const char *str;
+		} if_then_else;
+		struct {
+			enum { O_FULL, O_LENGTH, O_SHORT } option;
+			unsigned int length;
+		} objectname;
+		struct refname_atom refname;
 	} u;
 } *used_atom;
 static int used_atom_cnt, need_tagged, need_symref;
@@ -58,18 +106,58 @@
 		die(_("unrecognized color: %%(color:%s)"), color_value);
 }
 
-static void remote_ref_atom_parser(struct used_atom *atom, const char *arg)
+static void refname_atom_parser_internal(struct refname_atom *atom,
+					 const char *arg, const char *name)
 {
 	if (!arg)
-		atom->u.remote_ref = RR_NORMAL;
+		atom->option = R_NORMAL;
 	else if (!strcmp(arg, "short"))
-		atom->u.remote_ref = RR_SHORTEN;
-	else if (!strcmp(arg, "track"))
-		atom->u.remote_ref = RR_TRACK;
-	else if (!strcmp(arg, "trackshort"))
-		atom->u.remote_ref = RR_TRACKSHORT;
-	else
-		die(_("unrecognized format: %%(%s)"), atom->name);
+		atom->option = R_SHORT;
+	else if (skip_prefix(arg, "lstrip=", &arg) ||
+		 skip_prefix(arg, "strip=", &arg)) {
+		atom->option = R_LSTRIP;
+		if (strtol_i(arg, 10, &atom->lstrip))
+			die(_("Integer value expected refname:lstrip=%s"), arg);
+	} else if (skip_prefix(arg, "rstrip=", &arg)) {
+		atom->option = R_RSTRIP;
+		if (strtol_i(arg, 10, &atom->rstrip))
+			die(_("Integer value expected refname:rstrip=%s"), arg);
+	} else
+		die(_("unrecognized %%(%s) argument: %s"), name, arg);
+}
+
+static void remote_ref_atom_parser(struct used_atom *atom, const char *arg)
+{
+	struct string_list params = STRING_LIST_INIT_DUP;
+	int i;
+
+	if (!arg) {
+		atom->u.remote_ref.option = RR_REF;
+		refname_atom_parser_internal(&atom->u.remote_ref.refname,
+					     arg, atom->name);
+		return;
+	}
+
+	atom->u.remote_ref.nobracket = 0;
+	string_list_split(&params, arg, ',', -1);
+
+	for (i = 0; i < params.nr; i++) {
+		const char *s = params.items[i].string;
+
+		if (!strcmp(s, "track"))
+			atom->u.remote_ref.option = RR_TRACK;
+		else if (!strcmp(s, "trackshort"))
+			atom->u.remote_ref.option = RR_TRACKSHORT;
+		else if (!strcmp(s, "nobracket"))
+			atom->u.remote_ref.nobracket = 1;
+		else {
+			atom->u.remote_ref.option = RR_REF;
+			refname_atom_parser_internal(&atom->u.remote_ref.refname,
+						     arg, atom->name);
+		}
+	}
+
+	string_list_clear(&params, 0);
 }
 
 static void body_atom_parser(struct used_atom *atom, const char *arg)
@@ -116,13 +204,25 @@
 static void objectname_atom_parser(struct used_atom *atom, const char *arg)
 {
 	if (!arg)
-		atom->u.objectname = O_FULL;
+		atom->u.objectname.option = O_FULL;
 	else if (!strcmp(arg, "short"))
-		atom->u.objectname = O_SHORT;
-	else
+		atom->u.objectname.option = O_SHORT;
+	else if (skip_prefix(arg, "short=", &arg)) {
+		atom->u.objectname.option = O_LENGTH;
+		if (strtoul_ui(arg, 10, &atom->u.objectname.length) ||
+		    atom->u.objectname.length == 0)
+			die(_("positive value expected objectname:short=%s"), arg);
+		if (atom->u.objectname.length < MINIMUM_ABBREV)
+			atom->u.objectname.length = MINIMUM_ABBREV;
+	} else
 		die(_("unrecognized %%(objectname) argument: %s"), arg);
 }
 
+static void refname_atom_parser(struct used_atom *atom, const char *arg)
+{
+	return refname_atom_parser_internal(&atom->u.refname, arg, atom->name);
+}
+
 static align_type parse_align_position(const char *s)
 {
 	if (!strcmp(s, "right"))
@@ -173,12 +273,27 @@
 	string_list_clear(&params, 0);
 }
 
+static void if_atom_parser(struct used_atom *atom, const char *arg)
+{
+	if (!arg) {
+		atom->u.if_then_else.cmp_status = COMPARE_NONE;
+		return;
+	} else if (skip_prefix(arg, "equals=", &atom->u.if_then_else.str)) {
+		atom->u.if_then_else.cmp_status = COMPARE_EQUAL;
+	} else if (skip_prefix(arg, "notequals=", &atom->u.if_then_else.str)) {
+		atom->u.if_then_else.cmp_status = COMPARE_UNEQUAL;
+	} else {
+		die(_("unrecognized %%(if) argument: %s"), arg);
+	}
+}
+
+
 static struct {
 	const char *name;
 	cmp_type cmp_type;
 	void (*parser)(struct used_atom *atom, const char *arg);
 } valid_atom[] = {
-	{ "refname" },
+	{ "refname" , FIELD_STR, refname_atom_parser },
 	{ "objecttype" },
 	{ "objectsize", FIELD_ULONG },
 	{ "objectname", FIELD_STR, objectname_atom_parser },
@@ -208,12 +323,15 @@
 	{ "contents", FIELD_STR, contents_atom_parser },
 	{ "upstream", FIELD_STR, remote_ref_atom_parser },
 	{ "push", FIELD_STR, remote_ref_atom_parser },
-	{ "symref" },
+	{ "symref", FIELD_STR, refname_atom_parser },
 	{ "flag" },
 	{ "HEAD" },
 	{ "color", FIELD_STR, color_atom_parser },
 	{ "align", FIELD_STR, align_atom_parser },
 	{ "end" },
+	{ "if", FIELD_STR, if_atom_parser },
+	{ "then" },
+	{ "else" },
 };
 
 #define REF_FORMATTING_STATE_INIT  { 0, NULL }
@@ -221,7 +339,7 @@
 struct ref_formatting_stack {
 	struct ref_formatting_stack *prev;
 	struct strbuf output;
-	void (*at_end)(struct ref_formatting_stack *stack);
+	void (*at_end)(struct ref_formatting_stack **stack);
 	void *at_end_data;
 };
 
@@ -232,11 +350,9 @@
 
 struct atom_value {
 	const char *s;
-	union {
-		struct align align;
-	} u;
 	void (*handler)(struct atom_value *atomv, struct ref_formatting_state *state);
 	unsigned long ul; /* used for sorting when not FIELD_STR */
+	struct used_atom *atom;
 };
 
 /*
@@ -293,7 +409,7 @@
 		valid_atom[i].parser(&used_atom[at], arg);
 	if (*atom == '*')
 		need_tagged = 1;
-	if (!strcmp(used_atom[at].name, "symref"))
+	if (!strcmp(valid_atom[i].name, "symref"))
 		need_symref = 1;
 	return at;
 }
@@ -354,13 +470,14 @@
 	*stack = prev;
 }
 
-static void end_align_handler(struct ref_formatting_stack *stack)
+static void end_align_handler(struct ref_formatting_stack **stack)
 {
-	struct align *align = (struct align *)stack->at_end_data;
+	struct ref_formatting_stack *cur = *stack;
+	struct align *align = (struct align *)cur->at_end_data;
 	struct strbuf s = STRBUF_INIT;
 
-	strbuf_utf8_align(&s, align->position, align->width, stack->output.buf);
-	strbuf_swap(&stack->output, &s);
+	strbuf_utf8_align(&s, align->position, align->width, cur->output.buf);
+	strbuf_swap(&cur->output, &s);
 	strbuf_release(&s);
 }
 
@@ -371,7 +488,115 @@
 	push_stack_element(&state->stack);
 	new = state->stack;
 	new->at_end = end_align_handler;
-	new->at_end_data = &atomv->u.align;
+	new->at_end_data = &atomv->atom->u.align;
+}
+
+static void if_then_else_handler(struct ref_formatting_stack **stack)
+{
+	struct ref_formatting_stack *cur = *stack;
+	struct ref_formatting_stack *prev = cur->prev;
+	struct if_then_else *if_then_else = (struct if_then_else *)cur->at_end_data;
+
+	if (!if_then_else->then_atom_seen)
+		die(_("format: %%(if) atom used without a %%(then) atom"));
+
+	if (if_then_else->else_atom_seen) {
+		/*
+		 * There is an %(else) atom: we need to drop one state from the
+		 * stack, either the %(else) branch if the condition is satisfied, or
+		 * the %(then) branch if it isn't.
+		 */
+		if (if_then_else->condition_satisfied) {
+			strbuf_reset(&cur->output);
+			pop_stack_element(&cur);
+		} else {
+			strbuf_swap(&cur->output, &prev->output);
+			strbuf_reset(&cur->output);
+			pop_stack_element(&cur);
+		}
+	} else if (!if_then_else->condition_satisfied) {
+		/*
+		 * No %(else) atom: just drop the %(then) branch if the
+		 * condition is not satisfied.
+		 */
+		strbuf_reset(&cur->output);
+	}
+
+	*stack = cur;
+	free(if_then_else);
+}
+
+static void if_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+{
+	struct ref_formatting_stack *new;
+	struct if_then_else *if_then_else = xcalloc(sizeof(struct if_then_else), 1);
+
+	if_then_else->str = atomv->atom->u.if_then_else.str;
+	if_then_else->cmp_status = atomv->atom->u.if_then_else.cmp_status;
+
+	push_stack_element(&state->stack);
+	new = state->stack;
+	new->at_end = if_then_else_handler;
+	new->at_end_data = if_then_else;
+}
+
+static int is_empty(const char *s)
+{
+	while (*s != '\0') {
+		if (!isspace(*s))
+			return 0;
+		s++;
+	}
+	return 1;
+}
+
+static void then_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+{
+	struct ref_formatting_stack *cur = state->stack;
+	struct if_then_else *if_then_else = NULL;
+
+	if (cur->at_end == if_then_else_handler)
+		if_then_else = (struct if_then_else *)cur->at_end_data;
+	if (!if_then_else)
+		die(_("format: %%(then) atom used without an %%(if) atom"));
+	if (if_then_else->then_atom_seen)
+		die(_("format: %%(then) atom used more than once"));
+	if (if_then_else->else_atom_seen)
+		die(_("format: %%(then) atom used after %%(else)"));
+	if_then_else->then_atom_seen = 1;
+	/*
+	 * If the 'equals' or 'notequals' attribute is used then
+	 * perform the required comparison. If not, only non-empty
+	 * strings satisfy the 'if' condition.
+	 */
+	if (if_then_else->cmp_status == COMPARE_EQUAL) {
+		if (!strcmp(if_then_else->str, cur->output.buf))
+			if_then_else->condition_satisfied = 1;
+	} else if (if_then_else->cmp_status == COMPARE_UNEQUAL) {
+		if (strcmp(if_then_else->str, cur->output.buf))
+			if_then_else->condition_satisfied = 1;
+	} else if (cur->output.len && !is_empty(cur->output.buf))
+		if_then_else->condition_satisfied = 1;
+	strbuf_reset(&cur->output);
+}
+
+static void else_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+{
+	struct ref_formatting_stack *prev = state->stack;
+	struct if_then_else *if_then_else = NULL;
+
+	if (prev->at_end == if_then_else_handler)
+		if_then_else = (struct if_then_else *)prev->at_end_data;
+	if (!if_then_else)
+		die(_("format: %%(else) atom used without an %%(if) atom"));
+	if (!if_then_else->then_atom_seen)
+		die(_("format: %%(else) atom used without a %%(then) atom"));
+	if (if_then_else->else_atom_seen)
+		die(_("format: %%(else) atom used more than once"));
+	if_then_else->else_atom_seen = 1;
+	push_stack_element(&state->stack);
+	state->stack->at_end_data = prev->at_end_data;
+	state->stack->at_end = prev->at_end;
 }
 
 static void end_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
@@ -381,14 +606,17 @@
 
 	if (!current->at_end)
 		die(_("format: %%(end) atom used without corresponding atom"));
-	current->at_end(current);
+	current->at_end(&state->stack);
+
+	/*  Stack may have been popped within at_end(), hence reset the current pointer */
+	current = state->stack;
 
 	/*
 	 * Perform quote formatting when the stack element is that of
 	 * a supporting atom. If nested then perform quote formatting
 	 * only on the topmost supporting atom.
 	 */
-	if (!state->stack->prev->prev) {
+	if (!current->prev->prev) {
 		quote_formatting(&s, current->output.buf, state->quote_style);
 		strbuf_swap(&current->output, &s);
 	}
@@ -465,12 +693,15 @@
 			   struct atom_value *v, struct used_atom *atom)
 {
 	if (starts_with(name, "objectname")) {
-		if (atom->u.objectname == O_SHORT) {
+		if (atom->u.objectname.option == O_SHORT) {
 			v->s = xstrdup(find_unique_abbrev(sha1, DEFAULT_ABBREV));
 			return 1;
-		} else if (atom->u.objectname == O_FULL) {
+		} else if (atom->u.objectname.option == O_FULL) {
 			v->s = xstrdup(sha1_to_hex(sha1));
 			return 1;
+		} else if (atom->u.objectname.option == O_LENGTH) {
+			v->s = xstrdup(find_unique_abbrev(sha1, atom->u.objectname.length));
+			return 1;
 		} else
 			die("BUG: unknown %%(objectname) option");
 	}
@@ -887,50 +1118,108 @@
 	return dst;
 }
 
-static const char *strip_ref_components(const char *refname, const char *nr_arg)
+static const char *lstrip_ref_components(const char *refname, int len)
 {
-	char *end;
-	long nr = strtol(nr_arg, &end, 10);
-	long remaining = nr;
+	long remaining = len;
 	const char *start = refname;
 
-	if (nr < 1 || *end != '\0')
-		die(_(":strip= requires a positive integer argument"));
+	if (len < 0) {
+		int i;
+		const char *p = refname;
 
-	while (remaining) {
+		/* Find total no of '/' separated path-components */
+		for (i = 0; p[i]; p[i] == '/' ? i++ : *p++)
+			;
+		/*
+		 * The number of components we need to strip is now
+		 * the total minus the components to be left (Plus one
+		 * because we count the number of '/', but the number
+		 * of components is one more than the no of '/').
+		 */
+		remaining = i + len + 1;
+	}
+
+	while (remaining > 0) {
 		switch (*start++) {
 		case '\0':
-			die(_("ref '%s' does not have %ld components to :strip"),
-			    refname, nr);
+			return "";
 		case '/':
 			remaining--;
 			break;
 		}
 	}
+
 	return start;
 }
 
+static const char *rstrip_ref_components(const char *refname, int len)
+{
+	long remaining = len;
+	char *start = xstrdup(refname);
+
+	if (len < 0) {
+		int i;
+		const char *p = refname;
+
+		/* Find total no of '/' separated path-components */
+		for (i = 0; p[i]; p[i] == '/' ? i++ : *p++)
+			;
+		/*
+		 * The number of components we need to strip is now
+		 * the total minus the components to be left (Plus one
+		 * because we count the number of '/', but the number
+		 * of components is one more than the no of '/').
+		 */
+		remaining = i + len + 1;
+	}
+
+	while (remaining-- > 0) {
+		char *p = strrchr(start, '/');
+		if (p == NULL)
+			return "";
+		else
+			p[0] = '\0';
+	}
+	return start;
+}
+
+static const char *show_ref(struct refname_atom *atom, const char *refname)
+{
+	if (atom->option == R_SHORT)
+		return shorten_unambiguous_ref(refname, warn_ambiguous_refs);
+	else if (atom->option == R_LSTRIP)
+		return lstrip_ref_components(refname, atom->lstrip);
+	else if (atom->option == R_RSTRIP)
+		return rstrip_ref_components(refname, atom->rstrip);
+	else
+		return refname;
+}
+
 static void fill_remote_ref_details(struct used_atom *atom, const char *refname,
 				    struct branch *branch, const char **s)
 {
 	int num_ours, num_theirs;
-	if (atom->u.remote_ref == RR_SHORTEN)
-		*s = shorten_unambiguous_ref(refname, warn_ambiguous_refs);
-	else if (atom->u.remote_ref == RR_TRACK) {
+	if (atom->u.remote_ref.option == RR_REF)
+		*s = show_ref(&atom->u.remote_ref.refname, refname);
+	else if (atom->u.remote_ref.option == RR_TRACK) {
 		if (stat_tracking_info(branch, &num_ours,
-				       &num_theirs, NULL))
-			return;
-
-		if (!num_ours && !num_theirs)
+				       &num_theirs, NULL)) {
+			*s = xstrdup(msgs.gone);
+		} else if (!num_ours && !num_theirs)
 			*s = "";
 		else if (!num_ours)
-			*s = xstrfmt("[behind %d]", num_theirs);
+			*s = xstrfmt(msgs.behind, num_theirs);
 		else if (!num_theirs)
-			*s = xstrfmt("[ahead %d]", num_ours);
+			*s = xstrfmt(msgs.ahead, num_ours);
 		else
-			*s = xstrfmt("[ahead %d, behind %d]",
+			*s = xstrfmt(msgs.ahead_behind,
 				     num_ours, num_theirs);
-	} else if (atom->u.remote_ref == RR_TRACKSHORT) {
+		if (!atom->u.remote_ref.nobracket && *s[0]) {
+			const char *to_free = *s;
+			*s = xstrfmt("[%s]", *s);
+			free((void *)to_free);
+		}
+	} else if (atom->u.remote_ref.option == RR_TRACKSHORT) {
 		if (stat_tracking_info(branch, &num_ours,
 				       &num_theirs, NULL))
 			return;
@@ -943,8 +1232,56 @@
 			*s = ">";
 		else
 			*s = "<>";
-	} else /* RR_NORMAL */
-		*s = refname;
+	} else
+		die("BUG: unhandled RR_* enum");
+}
+
+char *get_head_description(void)
+{
+	struct strbuf desc = STRBUF_INIT;
+	struct wt_status_state state;
+	memset(&state, 0, sizeof(state));
+	wt_status_get_state(&state, 1);
+	if (state.rebase_in_progress ||
+	    state.rebase_interactive_in_progress)
+		strbuf_addf(&desc, _("(no branch, rebasing %s)"),
+			    state.branch);
+	else if (state.bisect_in_progress)
+		strbuf_addf(&desc, _("(no branch, bisect started on %s)"),
+			    state.branch);
+	else if (state.detached_from) {
+		if (state.detached_at)
+			/* TRANSLATORS: make sure this matches
+			   "HEAD detached at " in wt-status.c */
+			strbuf_addf(&desc, _("(HEAD detached at %s)"),
+				state.detached_from);
+		else
+			/* TRANSLATORS: make sure this matches
+			   "HEAD detached from " in wt-status.c */
+			strbuf_addf(&desc, _("(HEAD detached from %s)"),
+				state.detached_from);
+	}
+	else
+		strbuf_addstr(&desc, _("(no branch)"));
+	free(state.branch);
+	free(state.onto);
+	free(state.detached_from);
+	return strbuf_detach(&desc, NULL);
+}
+
+static const char *get_symref(struct used_atom *atom, struct ref_array_item *ref)
+{
+	if (!ref->symref)
+		return "";
+	else
+		return show_ref(&atom->u.refname, ref->symref);
+}
+
+static const char *get_refname(struct used_atom *atom, struct ref_array_item *ref)
+{
+	if (ref->kind & FILTER_REFS_DETACHED_HEAD)
+		return get_head_description();
+	return show_ref(&atom->u.refname, ref->refname);
 }
 
 /*
@@ -961,9 +1298,9 @@
 	ref->value = xcalloc(used_atom_cnt, sizeof(struct atom_value));
 
 	if (need_symref && (ref->flag & REF_ISSYMREF) && !ref->symref) {
-		unsigned char unused1[20];
+		struct object_id unused1;
 		ref->symref = resolve_refdup(ref->refname, RESOLVE_REF_READING,
-					     unused1, NULL);
+					     unused1.hash, NULL);
 		if (!ref->symref)
 			ref->symref = "";
 	}
@@ -975,10 +1312,10 @@
 		struct atom_value *v = &ref->value[i];
 		int deref = 0;
 		const char *refname;
-		const char *formatp;
 		struct branch *branch = NULL;
 
 		v->handler = append_atom;
+		v->atom = atom;
 
 		if (*name == '*') {
 			deref = 1;
@@ -986,9 +1323,9 @@
 		}
 
 		if (starts_with(name, "refname"))
-			refname = ref->refname;
+			refname = get_refname(atom, ref);
 		else if (starts_with(name, "symref"))
-			refname = ref->symref ? ref->symref : "";
+			refname = get_symref(atom, ref);
 		else if (starts_with(name, "upstream")) {
 			const char *branch_name;
 			/* only local branches may have an upstream */
@@ -1043,30 +1380,27 @@
 				v->s = " ";
 			continue;
 		} else if (starts_with(name, "align")) {
-			v->u.align = atom->u.align;
 			v->handler = align_atom_handler;
 			continue;
 		} else if (!strcmp(name, "end")) {
 			v->handler = end_atom_handler;
 			continue;
+		} else if (starts_with(name, "if")) {
+			const char *s;
+
+			if (skip_prefix(name, "if:", &s))
+				v->s = xstrdup(s);
+			v->handler = if_atom_handler;
+			continue;
+		} else if (!strcmp(name, "then")) {
+			v->handler = then_atom_handler;
+			continue;
+		} else if (!strcmp(name, "else")) {
+			v->handler = else_atom_handler;
+			continue;
 		} else
 			continue;
 
-		formatp = strchr(name, ':');
-		if (formatp) {
-			const char *arg;
-
-			formatp++;
-			if (!strcmp(formatp, "short"))
-				refname = shorten_unambiguous_ref(refname,
-						      warn_ambiguous_refs);
-			else if (skip_prefix(formatp, "strip=", &arg))
-				refname = strip_ref_components(refname, arg);
-			else
-				die(_("unknown %.*s format %s"),
-				    (int)(formatp - name), name, formatp);
-		}
-
 		if (!deref)
 			v->s = refname;
 		else
@@ -1137,10 +1471,22 @@
 	*v = &ref->value[atom];
 }
 
+/*
+ * Unknown has to be "0" here, because that's the default value for
+ * contains_cache slab entries that have not yet been assigned.
+ */
 enum contains_result {
-	CONTAINS_UNKNOWN = -1,
-	CONTAINS_NO = 0,
-	CONTAINS_YES = 1
+	CONTAINS_UNKNOWN = 0,
+	CONTAINS_NO,
+	CONTAINS_YES
+};
+
+define_commit_slab(contains_cache, enum contains_result);
+
+struct ref_filter_cbdata {
+	struct ref_array *array;
+	struct ref_filter *filter;
+	struct contains_cache contains_cache;
 };
 
 /*
@@ -1171,24 +1517,24 @@
  * Do not recurse to find out, though, but return -1 if inconclusive.
  */
 static enum contains_result contains_test(struct commit *candidate,
-			    const struct commit_list *want)
+					  const struct commit_list *want,
+					  struct contains_cache *cache)
 {
-	/* was it previously marked as containing a want commit? */
-	if (candidate->object.flags & TMP_MARK)
-		return 1;
-	/* or marked as not possibly containing a want commit? */
-	if (candidate->object.flags & UNINTERESTING)
-		return 0;
+	enum contains_result *cached = contains_cache_at(cache, candidate);
+
+	/* If we already have the answer cached, return that. */
+	if (*cached)
+		return *cached;
+
 	/* or are we it? */
 	if (in_commit_list(want, candidate)) {
-		candidate->object.flags |= TMP_MARK;
-		return 1;
+		*cached = CONTAINS_YES;
+		return CONTAINS_YES;
 	}
 
-	if (parse_commit(candidate) < 0)
-		return 0;
-
-	return -1;
+	/* Otherwise, we don't know; prepare to recurse */
+	parse_commit_or_die(candidate);
+	return CONTAINS_UNKNOWN;
 }
 
 static void push_to_contains_stack(struct commit *candidate, struct contains_stack *contains_stack)
@@ -1199,10 +1545,11 @@
 }
 
 static enum contains_result contains_tag_algo(struct commit *candidate,
-		const struct commit_list *want)
+					      const struct commit_list *want,
+					      struct contains_cache *cache)
 {
 	struct contains_stack contains_stack = { 0, 0, NULL };
-	int result = contains_test(candidate, want);
+	enum contains_result result = contains_test(candidate, want, cache);
 
 	if (result != CONTAINS_UNKNOWN)
 		return result;
@@ -1214,16 +1561,16 @@
 		struct commit_list *parents = entry->parents;
 
 		if (!parents) {
-			commit->object.flags |= UNINTERESTING;
+			*contains_cache_at(cache, commit) = CONTAINS_NO;
 			contains_stack.nr--;
 		}
 		/*
 		 * If we just popped the stack, parents->item has been marked,
-		 * therefore contains_test will return a meaningful 0 or 1.
+		 * therefore contains_test will return a meaningful yes/no.
 		 */
-		else switch (contains_test(parents->item, want)) {
+		else switch (contains_test(parents->item, want, cache)) {
 		case CONTAINS_YES:
-			commit->object.flags |= TMP_MARK;
+			*contains_cache_at(cache, commit) = CONTAINS_YES;
 			contains_stack.nr--;
 			break;
 		case CONTAINS_NO:
@@ -1235,13 +1582,14 @@
 		}
 	}
 	free(contains_stack.contains_stack);
-	return contains_test(candidate, want);
+	return contains_test(candidate, want, cache);
 }
 
-static int commit_contains(struct ref_filter *filter, struct commit *commit)
+static int commit_contains(struct ref_filter *filter, struct commit *commit,
+			   struct contains_cache *cache)
 {
 	if (filter->with_commit_tag_algo)
-		return contains_tag_algo(commit, filter->with_commit);
+		return contains_tag_algo(commit, filter->with_commit, cache) == CONTAINS_YES;
 	return is_descendant_of(commit, filter->with_commit);
 }
 
@@ -1438,7 +1786,7 @@
 			return 0;
 		/* We perform the filtering for the '--contains' option */
 		if (filter->with_commit &&
-		    !commit_contains(filter, commit))
+		    !commit_contains(filter, commit, &ref_cbdata->contains_cache))
 			return 0;
 	}
 
@@ -1538,6 +1886,8 @@
 		broken = 1;
 	filter->kind = type & FILTER_REFS_KIND_MASK;
 
+	init_contains_cache(&ref_cbdata.contains_cache);
+
 	/*  Simple per-ref filtering */
 	if (!filter->kind)
 		die("filter_refs: invalid type");
@@ -1560,6 +1910,7 @@
 			head_ref(ref_filter_handler, &ref_cbdata);
 	}
 
+	clear_contains_cache(&ref_cbdata.contains_cache);
 
 	/*  Filters that need revision walking */
 	if (filter->merge_commit)
@@ -1635,10 +1986,10 @@
 	}
 }
 
-void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style)
+void format_ref_array_item(struct ref_array_item *info, const char *format,
+			   int quote_style, struct strbuf *final_buf)
 {
 	const char *cp, *sp, *ep;
-	struct strbuf *final_buf;
 	struct ref_formatting_state state = REF_FORMATTING_STATE_INIT;
 
 	state.quote_style = quote_style;
@@ -1668,9 +2019,17 @@
 	}
 	if (state.stack->prev)
 		die(_("format: %%(end) atom missing"));
-	final_buf = &state.stack->output;
-	fwrite(final_buf->buf, 1, final_buf->len, stdout);
+	strbuf_addbuf(final_buf, &state.stack->output);
 	pop_stack_element(&state.stack);
+}
+
+void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style)
+{
+	struct strbuf final_buf = STRBUF_INIT;
+
+	format_ref_array_item(info, format, quote_style, &final_buf);
+	fwrite(final_buf.buf, 1, final_buf.len, stdout);
+	strbuf_release(&final_buf);
 	putchar('\n');
 }
 
diff --git a/ref-filter.h b/ref-filter.h
index 7b05592..e738c5d 100644
--- a/ref-filter.h
+++ b/ref-filter.h
@@ -71,11 +71,6 @@
 		verbose;
 };
 
-struct ref_filter_cbdata {
-	struct ref_array *array;
-	struct ref_filter *filter;
-};
-
 /*  Macros for checking --merged and --no-merged options */
 #define _OPT_MERGED_NO_MERGED(option, filter, h) \
 	{ OPTION_CALLBACK, 0, option, (filter), N_("commit"), (h), \
@@ -100,6 +95,9 @@
 int verify_ref_format(const char *format);
 /*  Sort the given ref_array as per the ref_sorting provided */
 void ref_array_sort(struct ref_sorting *sort, struct ref_array *array);
+/*  Based on the given format and quote_style, fill the strbuf */
+void format_ref_array_item(struct ref_array_item *info, const char *format,
+			   int quote_style, struct strbuf *final_buf);
 /*  Print the ref using the given format and quote_style */
 void show_ref_array_item(struct ref_array_item *info, const char *format, int quote_style);
 /*  Callback function for parsing the sort option */
@@ -108,6 +106,10 @@
 struct ref_sorting *ref_default_sorting(void);
 /*  Function to parse --merged and --no-merged options */
 int parse_opt_merge_filter(const struct option *opt, const char *arg, int unset);
+/*  Get the current HEAD's description */
+char *get_head_description(void);
+/*  Set up translated strings in the output. */
+void setup_ref_filter_porcelain_msg(void);
 
 /*
  * Print a single ref, outside of any ref-filter. Note that the
diff --git a/reflog-walk.c b/reflog-walk.c
index a246af2..99679f5 100644
--- a/reflog-walk.c
+++ b/reflog-walk.c
@@ -10,7 +10,7 @@
 	char *ref;
 	const char *short_ref;
 	struct reflog_info {
-		unsigned char osha1[20], nsha1[20];
+		struct object_id ooid, noid;
 		char *email;
 		unsigned long timestamp;
 		int tz;
@@ -19,7 +19,7 @@
 	int nr, alloc;
 };
 
-static int read_one_reflog(unsigned char *osha1, unsigned char *nsha1,
+static int read_one_reflog(struct object_id *ooid, struct object_id *noid,
 		const char *email, unsigned long timestamp, int tz,
 		const char *message, void *cb_data)
 {
@@ -28,8 +28,8 @@
 
 	ALLOC_GROW(array->items, array->nr + 1, array->alloc);
 	item = array->items + array->nr;
-	hashcpy(item->osha1, osha1);
-	hashcpy(item->nsha1, nsha1);
+	oidcpy(&item->ooid, ooid);
+	oidcpy(&item->noid, noid);
 	item->email = xstrdup(email);
 	item->timestamp = timestamp;
 	item->tz = tz;
@@ -45,11 +45,11 @@
 	reflogs->ref = xstrdup(ref);
 	for_each_reflog_ent(ref, read_one_reflog, reflogs);
 	if (reflogs->nr == 0) {
-		unsigned char sha1[20];
+		struct object_id oid;
 		const char *name;
 		void *name_to_free;
 		name = name_to_free = resolve_refdup(ref, RESOLVE_REF_READING,
-						     sha1, NULL);
+						     oid.hash, NULL);
 		if (name) {
 			for_each_reflog_ent(name, read_one_reflog, reflogs);
 			free(name_to_free);
@@ -172,18 +172,18 @@
 		reflogs = item->util;
 	else {
 		if (*branch == '\0') {
-			unsigned char sha1[20];
+			struct object_id oid;
 			free(branch);
-			branch = resolve_refdup("HEAD", 0, sha1, NULL);
+			branch = resolve_refdup("HEAD", 0, oid.hash, NULL);
 			if (!branch)
 				die ("No current branch");
 
 		}
 		reflogs = read_complete_reflog(branch);
 		if (!reflogs || reflogs->nr == 0) {
-			unsigned char sha1[20];
+			struct object_id oid;
 			char *b;
-			if (dwim_log(branch, strlen(branch), sha1, &b) == 1) {
+			if (dwim_log(branch, strlen(branch), oid.hash, &b) == 1) {
 				if (reflogs) {
 					free(reflogs->ref);
 					free(reflogs);
@@ -238,13 +238,13 @@
 	do {
 		reflog = &commit_reflog->reflogs->items[commit_reflog->recno];
 		commit_reflog->recno--;
-		logobj = parse_object(reflog->osha1);
+		logobj = parse_object(reflog->ooid.hash);
 	} while (commit_reflog->recno && (logobj && logobj->type != OBJ_COMMIT));
 
-	if (!logobj && commit_reflog->recno >= 0 && is_null_sha1(reflog->osha1)) {
+	if (!logobj && commit_reflog->recno >= 0 && is_null_sha1(reflog->ooid.hash)) {
 		/* a root commit, but there are still more entries to show */
 		reflog = &commit_reflog->reflogs->items[commit_reflog->recno];
-		logobj = parse_object(reflog->nsha1);
+		logobj = parse_object(reflog->noid.hash);
 	}
 
 	if (!logobj || logobj->type != OBJ_COMMIT) {
diff --git a/refs.c b/refs.c
index cd36b64..e760671 100644
--- a/refs.c
+++ b/refs.c
@@ -3,6 +3,7 @@
  */
 
 #include "cache.h"
+#include "hashmap.h"
 #include "lockfile.h"
 #include "refs.h"
 #include "refs/refs-internal.h"
@@ -404,7 +405,7 @@
 static char *substitute_branch_name(const char **string, int *len)
 {
 	struct strbuf buf = STRBUF_INIT;
-	int ret = interpret_branch_name(*string, *len, &buf);
+	int ret = interpret_branch_name(*string, *len, &buf, 0);
 
 	if (ret == *len) {
 		size_t size;
@@ -591,8 +592,8 @@
 	return 0;
 }
 
-int delete_ref(const char *refname, const unsigned char *old_sha1,
-	       unsigned int flags)
+int delete_ref(const char *msg, const char *refname,
+	       const unsigned char *old_sha1, unsigned int flags)
 {
 	struct ref_transaction *transaction;
 	struct strbuf err = STRBUF_INIT;
@@ -603,7 +604,7 @@
 	transaction = ref_transaction_begin(&err);
 	if (!transaction ||
 	    ref_transaction_delete(transaction, refname, old_sha1,
-				   flags, NULL, &err) ||
+				   flags, msg, &err) ||
 	    ref_transaction_commit(transaction, &err)) {
 		error("%s", err.buf);
 		ref_transaction_free(transaction);
@@ -674,7 +675,7 @@
 	int *cutoff_cnt;
 };
 
-static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1,
+static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
 		const char *email, unsigned long timestamp, int tz,
 		const char *message, void *cb_data)
 {
@@ -698,30 +699,30 @@
 		 * hold the values for the previous record.
 		 */
 		if (!is_null_sha1(cb->osha1)) {
-			hashcpy(cb->sha1, nsha1);
-			if (hashcmp(cb->osha1, nsha1))
+			hashcpy(cb->sha1, noid->hash);
+			if (hashcmp(cb->osha1, noid->hash))
 				warning("Log for ref %s has gap after %s.",
 					cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
 		}
 		else if (cb->date == cb->at_time)
-			hashcpy(cb->sha1, nsha1);
-		else if (hashcmp(nsha1, cb->sha1))
+			hashcpy(cb->sha1, noid->hash);
+		else if (hashcmp(noid->hash, cb->sha1))
 			warning("Log for ref %s unexpectedly ended on %s.",
 				cb->refname, show_date(cb->date, cb->tz,
 						       DATE_MODE(RFC2822)));
-		hashcpy(cb->osha1, osha1);
-		hashcpy(cb->nsha1, nsha1);
+		hashcpy(cb->osha1, ooid->hash);
+		hashcpy(cb->nsha1, noid->hash);
 		cb->found_it = 1;
 		return 1;
 	}
-	hashcpy(cb->osha1, osha1);
-	hashcpy(cb->nsha1, nsha1);
+	hashcpy(cb->osha1, ooid->hash);
+	hashcpy(cb->nsha1, noid->hash);
 	if (cb->cnt > 0)
 		cb->cnt--;
 	return 0;
 }
 
-static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1,
+static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
 				  const char *email, unsigned long timestamp,
 				  int tz, const char *message, void *cb_data)
 {
@@ -735,9 +736,9 @@
 		*cb->cutoff_tz = tz;
 	if (cb->cutoff_cnt)
 		*cb->cutoff_cnt = cb->reccnt;
-	hashcpy(cb->sha1, osha1);
+	hashcpy(cb->sha1, ooid->hash);
 	if (is_null_sha1(cb->sha1))
-		hashcpy(cb->sha1, nsha1);
+		hashcpy(cb->sha1, noid->hash);
 	/* We just want the first entry */
 	return 1;
 }
@@ -1034,10 +1035,10 @@
 
 int parse_hide_refs_config(const char *var, const char *value, const char *section)
 {
+	const char *key;
 	if (!strcmp("transfer.hiderefs", var) ||
-	    /* NEEDSWORK: use parse_config_key() once both are merged */
-	    (starts_with(var, section) && var[strlen(section)] == '.' &&
-	     !strcmp(var + strlen(section), ".hiderefs"))) {
+	    (!parse_config_key(var, section, NULL, NULL, &key) &&
+	     !strcmp(key, "hiderefs"))) {
 		char *ref;
 		int len;
 
@@ -1234,10 +1235,10 @@
 }
 
 /* This function needs to return a meaningful errno on failure */
-static const char *resolve_ref_recursively(struct ref_store *refs,
-					   const char *refname,
-					   int resolve_flags,
-					   unsigned char *sha1, int *flags)
+const char *resolve_ref_recursively(struct ref_store *refs,
+				    const char *refname,
+				    int resolve_flags,
+				    unsigned char *sha1, int *flags)
 {
 	static struct strbuf sb_refname = STRBUF_INIT;
 	int unused_flags;
@@ -1357,62 +1358,102 @@
 	return 0;
 }
 
+struct submodule_hash_entry
+{
+	struct hashmap_entry ent; /* must be the first member! */
+
+	struct ref_store *refs;
+
+	/* NUL-terminated name of submodule: */
+	char submodule[FLEX_ARRAY];
+};
+
+static int submodule_hash_cmp(const void *entry, const void *entry_or_key,
+			      const void *keydata)
+{
+	const struct submodule_hash_entry *e1 = entry, *e2 = entry_or_key;
+	const char *submodule = keydata ? keydata : e2->submodule;
+
+	return strcmp(e1->submodule, submodule);
+}
+
+static struct submodule_hash_entry *alloc_submodule_hash_entry(
+		const char *submodule, struct ref_store *refs)
+{
+	struct submodule_hash_entry *entry;
+
+	FLEX_ALLOC_STR(entry, submodule, submodule);
+	hashmap_entry_init(entry, strhash(submodule));
+	entry->refs = refs;
+	return entry;
+}
+
 /* A pointer to the ref_store for the main repository: */
 static struct ref_store *main_ref_store;
 
-/* A linked list of ref_stores for submodules: */
-static struct ref_store *submodule_ref_stores;
+/* A hashmap of ref_stores, stored by submodule name: */
+static struct hashmap submodule_ref_stores;
 
-void base_ref_store_init(struct ref_store *refs,
-			 const struct ref_storage_be *be,
-			 const char *submodule)
+/*
+ * Return the ref_store instance for the specified submodule (or the
+ * main repository if submodule is NULL). If that ref_store hasn't
+ * been initialized yet, return NULL.
+ */
+static struct ref_store *lookup_ref_store(const char *submodule)
 {
-	refs->be = be;
+	struct submodule_hash_entry *entry;
+
+	if (!submodule)
+		return main_ref_store;
+
+	if (!submodule_ref_stores.tablesize)
+		/* It's initialized on demand in register_ref_store(). */
+		return NULL;
+
+	entry = hashmap_get_from_hash(&submodule_ref_stores,
+				      strhash(submodule), submodule);
+	return entry ? entry->refs : NULL;
+}
+
+/*
+ * Register the specified ref_store to be the one that should be used
+ * for submodule (or the main repository if submodule is NULL). It is
+ * a fatal error to call this function twice for the same submodule.
+ */
+static void register_ref_store(struct ref_store *refs, const char *submodule)
+{
 	if (!submodule) {
 		if (main_ref_store)
 			die("BUG: main_ref_store initialized twice");
 
-		refs->submodule = "";
-		refs->next = NULL;
 		main_ref_store = refs;
 	} else {
-		if (lookup_ref_store(submodule))
+		if (!submodule_ref_stores.tablesize)
+			hashmap_init(&submodule_ref_stores, submodule_hash_cmp, 0);
+
+		if (hashmap_put(&submodule_ref_stores,
+				alloc_submodule_hash_entry(submodule, refs)))
 			die("BUG: ref_store for submodule '%s' initialized twice",
 			    submodule);
-
-		refs->submodule = xstrdup(submodule);
-		refs->next = submodule_ref_stores;
-		submodule_ref_stores = refs;
 	}
 }
 
-struct ref_store *ref_store_init(const char *submodule)
+/*
+ * Create, record, and return a ref_store instance for the specified
+ * submodule (or the main repository if submodule is NULL).
+ */
+static struct ref_store *ref_store_init(const char *submodule)
 {
 	const char *be_name = "files";
 	struct ref_storage_be *be = find_ref_storage_backend(be_name);
+	struct ref_store *refs;
 
 	if (!be)
 		die("BUG: reference backend %s is unknown", be_name);
 
-	if (!submodule || !*submodule)
-		return be->init(NULL);
-	else
-		return be->init(submodule);
-}
-
-struct ref_store *lookup_ref_store(const char *submodule)
-{
-	struct ref_store *refs;
-
-	if (!submodule || !*submodule)
-		return main_ref_store;
-
-	for (refs = submodule_ref_stores; refs; refs = refs->next) {
-		if (!strcmp(submodule, refs->submodule))
-			return refs;
-	}
-
-	return NULL;
+	refs = be->init(submodule);
+	register_ref_store(refs, submodule);
+	return refs;
 }
 
 struct ref_store *get_ref_store(const char *submodule)
@@ -1440,10 +1481,10 @@
 	return refs;
 }
 
-void assert_main_repository(struct ref_store *refs, const char *caller)
+void base_ref_store_init(struct ref_store *refs,
+			 const struct ref_storage_be *be)
 {
-	if (*refs->submodule)
-		die("BUG: %s called for a submodule", caller);
+	refs->be = be;
 }
 
 /* backend functions */
diff --git a/refs.h b/refs.h
index 9fbff90..3df0d45 100644
--- a/refs.h
+++ b/refs.h
@@ -276,8 +276,8 @@
  * exists, regardless of its old value. It is an error for old_sha1 to
  * be NULL_SHA1. flags is passed through to ref_transaction_delete().
  */
-int delete_ref(const char *refname, const unsigned char *old_sha1,
-	       unsigned int flags);
+int delete_ref(const char *msg, const char *refname,
+	       const unsigned char *old_sha1, unsigned int flags);
 
 /*
  * Delete the specified references. If there are any problems, emit
@@ -292,7 +292,7 @@
 
 /* iterate over reflog entries */
 typedef int each_reflog_ent_fn(
-		unsigned char *old_sha1, unsigned char *new_sha1,
+		struct object_id *old_oid, struct object_id *new_oid,
 		const char *committer, unsigned long timestamp,
 		int tz, const char *msg, void *cb_data);
 
@@ -334,7 +334,8 @@
  * $GIT_DIR points to.
  * Return 0 if successful, non-zero otherwise.
  * */
-int set_worktree_head_symref(const char *gitdir, const char *target);
+int set_worktree_head_symref(const char *gitdir, const char *target,
+			     const char *logmsg);
 
 enum action_on_err {
 	UPDATE_REFS_MSG_ON_ERR,
diff --git a/refs/files-backend.c b/refs/files-backend.c
index c041d4b..50188e9 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -912,6 +912,14 @@
  */
 struct files_ref_store {
 	struct ref_store base;
+
+	/*
+	 * The name of the submodule represented by this object, or
+	 * NULL if it represents the main repository's reference
+	 * store:
+	 */
+	const char *submodule;
+
 	struct ref_entry *loose;
 	struct packed_ref_cache *packed;
 };
@@ -972,12 +980,25 @@
 	struct files_ref_store *refs = xcalloc(1, sizeof(*refs));
 	struct ref_store *ref_store = (struct ref_store *)refs;
 
-	base_ref_store_init(ref_store, &refs_be_files, submodule);
+	base_ref_store_init(ref_store, &refs_be_files);
+
+	refs->submodule = xstrdup_or_null(submodule);
 
 	return ref_store;
 }
 
 /*
+ * Die if refs is for a submodule (i.e., not for the main repository).
+ * caller is used in any necessary error messages.
+ */
+static void files_assert_main_repository(struct files_ref_store *refs,
+					 const char *caller)
+{
+	if (refs->submodule)
+		die("BUG: %s called for a submodule", caller);
+}
+
+/*
  * Downcast ref_store to files_ref_store. Die if ref_store is not a
  * files_ref_store. If submodule_allowed is not true, then also die if
  * files_ref_store is for a submodule (i.e., not for the main
@@ -987,14 +1008,18 @@
 		struct ref_store *ref_store, int submodule_allowed,
 		const char *caller)
 {
+	struct files_ref_store *refs;
+
 	if (ref_store->be != &refs_be_files)
 		die("BUG: ref_store is type \"%s\" not \"files\" in %s",
 		    ref_store->be->name, caller);
 
-	if (!submodule_allowed)
-		assert_main_repository(ref_store, caller);
+	refs = (struct files_ref_store *)ref_store;
 
-	return (struct files_ref_store *)ref_store;
+	if (!submodule_allowed)
+		files_assert_main_repository(refs, caller);
+
+	return refs;
 }
 
 /* The length of a peeled reference line in packed-refs, including EOL: */
@@ -1133,8 +1158,8 @@
 {
 	char *packed_refs_file;
 
-	if (*refs->base.submodule)
-		packed_refs_file = git_pathdup_submodule(refs->base.submodule,
+	if (refs->submodule)
+		packed_refs_file = git_pathdup_submodule(refs->submodule,
 							 "packed-refs");
 	else
 		packed_refs_file = git_pathdup("packed-refs");
@@ -1203,8 +1228,8 @@
 	size_t path_baselen;
 	int err = 0;
 
-	if (*refs->base.submodule)
-		err = strbuf_git_path_submodule(&path, refs->base.submodule, "%s", dirname);
+	if (refs->submodule)
+		err = strbuf_git_path_submodule(&path, refs->submodule, "%s", dirname);
 	else
 		strbuf_git_path(&path, "%s", dirname);
 	path_baselen = path.len;
@@ -1242,20 +1267,10 @@
 					 create_dir_entry(refs, refname.buf,
 							  refname.len, 1));
 		} else {
-			int read_ok;
-
-			if (*refs->base.submodule) {
-				hashclr(sha1);
-				flag = 0;
-				read_ok = !resolve_gitlink_ref(refs->base.submodule,
-							       refname.buf, sha1);
-			} else {
-				read_ok = !read_ref_full(refname.buf,
-							 RESOLVE_REF_READING,
-							 sha1, &flag);
-			}
-
-			if (!read_ok) {
+			if (!resolve_ref_recursively(&refs->base,
+						     refname.buf,
+						     RESOLVE_REF_READING,
+						     sha1, &flag)) {
 				hashclr(sha1);
 				flag |= REF_ISBROKEN;
 			} else if (is_null_sha1(sha1)) {
@@ -1358,8 +1373,8 @@
 	*type = 0;
 	strbuf_reset(&sb_path);
 
-	if (*refs->base.submodule)
-		strbuf_git_path_submodule(&sb_path, refs->base.submodule, "%s", refname);
+	if (refs->submodule)
+		strbuf_git_path_submodule(&sb_path, refs->submodule, "%s", refname);
 	else
 		strbuf_git_path(&sb_path, "%s", refname);
 
@@ -1540,7 +1555,7 @@
 	int ret = TRANSACTION_GENERIC_ERROR;
 
 	assert(err);
-	assert_main_repository(&refs->base, "lock_raw_ref");
+	files_assert_main_repository(refs, "lock_raw_ref");
 
 	*type = 0;
 
@@ -1985,6 +2000,13 @@
 	return remove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);
 }
 
+static int create_reflock(const char *path, void *cb)
+{
+	struct lock_file *lk = cb;
+
+	return hold_lock_file_for_update(lk, path, LOCK_NO_DEREF) < 0 ? -1 : 0;
+}
+
 /*
  * Locks a ref returning the lock on success and NULL on failure.
  * On failure errno is set to something meaningful.
@@ -2000,13 +2022,11 @@
 	struct strbuf ref_file = STRBUF_INIT;
 	struct ref_lock *lock;
 	int last_errno = 0;
-	int lflags = LOCK_NO_DEREF;
 	int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
 	int resolve_flags = RESOLVE_REF_NO_RECURSE;
-	int attempts_remaining = 3;
 	int resolved;
 
-	assert_main_repository(&refs->base, "lock_ref_sha1_basic");
+	files_assert_main_repository(refs, "lock_ref_sha1_basic");
 	assert(err);
 
 	lock = xcalloc(1, sizeof(struct ref_lock));
@@ -2068,35 +2088,12 @@
 
 	lock->ref_name = xstrdup(refname);
 
- retry:
-	switch (safe_create_leading_directories_const(ref_file.buf)) {
-	case SCLD_OK:
-		break; /* success */
-	case SCLD_VANISHED:
-		if (--attempts_remaining > 0)
-			goto retry;
-		/* fall through */
-	default:
+	if (raceproof_create_file(ref_file.buf, create_reflock, lock->lk)) {
 		last_errno = errno;
-		strbuf_addf(err, "unable to create directory for '%s'",
-			    ref_file.buf);
+		unable_to_lock_message(ref_file.buf, errno, err);
 		goto error_return;
 	}
 
-	if (hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) < 0) {
-		last_errno = errno;
-		if (errno == ENOENT && --attempts_remaining > 0)
-			/*
-			 * Maybe somebody just deleted one of the
-			 * directories leading to ref_file.  Try
-			 * again:
-			 */
-			goto retry;
-		else {
-			unable_to_lock_message(ref_file.buf, errno, err);
-			goto error_return;
-		}
-	}
 	if (verify_lock(lock, old_sha1, mustexist, err)) {
 		last_errno = errno;
 		goto error_return;
@@ -2152,7 +2149,7 @@
 	static int timeout_value = 1000;
 	struct packed_ref_cache *packed_ref_cache;
 
-	assert_main_repository(&refs->base, "lock_packed_refs");
+	files_assert_main_repository(refs, "lock_packed_refs");
 
 	if (!timeout_configured) {
 		git_config_get_int("core.packedrefstimeout", &timeout_value);
@@ -2190,7 +2187,7 @@
 	int save_errno = 0;
 	FILE *out;
 
-	assert_main_repository(&refs->base, "commit_packed_refs");
+	files_assert_main_repository(refs, "commit_packed_refs");
 
 	if (!packed_ref_cache->lock)
 		die("internal error: packed-refs not locked");
@@ -2223,7 +2220,7 @@
 	struct packed_ref_cache *packed_ref_cache =
 		get_packed_ref_cache(refs);
 
-	assert_main_repository(&refs->base, "rollback_packed_refs");
+	files_assert_main_repository(refs, "rollback_packed_refs");
 
 	if (!packed_ref_cache->lock)
 		die("internal error: packed-refs not locked");
@@ -2298,15 +2295,25 @@
 	return 0;
 }
 
+enum {
+	REMOVE_EMPTY_PARENTS_REF = 0x01,
+	REMOVE_EMPTY_PARENTS_REFLOG = 0x02
+};
+
 /*
- * Remove empty parents, but spare refs/ and immediate subdirs.
- * Note: munges *name.
+ * Remove empty parent directories associated with the specified
+ * reference and/or its reflog, but spare [logs/]refs/ and immediate
+ * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or
+ * REMOVE_EMPTY_PARENTS_REFLOG.
  */
-static void try_remove_empty_parents(char *name)
+static void try_remove_empty_parents(const char *refname, unsigned int flags)
 {
+	struct strbuf buf = STRBUF_INIT;
 	char *p, *q;
 	int i;
-	p = name;
+
+	strbuf_addstr(&buf, refname);
+	p = buf.buf;
 	for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
 		while (*p && *p != '/')
 			p++;
@@ -2314,19 +2321,23 @@
 		while (*p == '/')
 			p++;
 	}
-	for (q = p; *q; q++)
-		;
-	while (1) {
+	q = buf.buf + buf.len;
+	while (flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) {
 		while (q > p && *q != '/')
 			q--;
 		while (q > p && *(q-1) == '/')
 			q--;
 		if (q == p)
 			break;
-		*q = '\0';
-		if (rmdir(git_path("%s", name)))
-			break;
+		strbuf_setlen(&buf, q - buf.buf);
+		if ((flags & REMOVE_EMPTY_PARENTS_REF) &&
+		    rmdir(git_path("%s", buf.buf)))
+			flags &= ~REMOVE_EMPTY_PARENTS_REF;
+		if ((flags & REMOVE_EMPTY_PARENTS_REFLOG) &&
+		    rmdir(git_path("logs/%s", buf.buf)))
+			flags &= ~REMOVE_EMPTY_PARENTS_REFLOG;
 	}
+	strbuf_release(&buf);
 }
 
 /* make sure nobody touched the ref, and unlink */
@@ -2350,7 +2361,6 @@
 	}
 	ref_transaction_free(transaction);
 	strbuf_release(&err);
-	try_remove_empty_parents(r->name);
 }
 
 static void prune_refs(struct ref_to_prune *r)
@@ -2397,7 +2407,7 @@
 	struct string_list_item *refname;
 	int ret, needs_repacking = 0, removed = 0;
 
-	assert_main_repository(&refs->base, "repack_without_refs");
+	files_assert_main_repository(refs, "repack_without_refs");
 	assert(err);
 
 	/* Look for a packed ref */
@@ -2439,24 +2449,6 @@
 	return ret;
 }
 
-static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)
-{
-	assert(err);
-
-	if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
-		/*
-		 * loose.  The loose file name is the same as the
-		 * lockfile name, minus ".lock":
-		 */
-		char *loose_filename = get_locked_file_path(lock->lk);
-		int res = unlink_or_msg(loose_filename, err);
-		free(loose_filename);
-		if (res)
-			return 1;
-	}
-	return 0;
-}
-
 static int files_delete_refs(struct ref_store *ref_store,
 			     struct string_list *refnames, unsigned int flags)
 {
@@ -2489,7 +2481,7 @@
 	for (i = 0; i < refnames->nr; i++) {
 		const char *refname = refnames->items[i].string;
 
-		if (delete_ref(refname, NULL, flags))
+		if (delete_ref(NULL, refname, NULL, flags))
 			result |= error(_("could not remove reference %s"), refname);
 	}
 
@@ -2507,55 +2499,43 @@
  */
 #define TMP_RENAMED_LOG  "logs/refs/.tmp-renamed-log"
 
+static int rename_tmp_log_callback(const char *path, void *cb)
+{
+	int *true_errno = cb;
+
+	if (rename(git_path(TMP_RENAMED_LOG), path)) {
+		/*
+		 * rename(a, b) when b is an existing directory ought
+		 * to result in ISDIR, but Solaris 5.8 gives ENOTDIR.
+		 * Sheesh. Record the true errno for error reporting,
+		 * but report EISDIR to raceproof_create_file() so
+		 * that it knows to retry.
+		 */
+		*true_errno = errno;
+		if (errno == ENOTDIR)
+			errno = EISDIR;
+		return -1;
+	} else {
+		return 0;
+	}
+}
+
 static int rename_tmp_log(const char *newrefname)
 {
-	int attempts_remaining = 4;
-	struct strbuf path = STRBUF_INIT;
-	int ret = -1;
+	char *path = git_pathdup("logs/%s", newrefname);
+	int ret, true_errno;
 
- retry:
-	strbuf_reset(&path);
-	strbuf_git_path(&path, "logs/%s", newrefname);
-	switch (safe_create_leading_directories_const(path.buf)) {
-	case SCLD_OK:
-		break; /* success */
-	case SCLD_VANISHED:
-		if (--attempts_remaining > 0)
-			goto retry;
-		/* fall through */
-	default:
-		error("unable to create directory for %s", newrefname);
-		goto out;
+	ret = raceproof_create_file(path, rename_tmp_log_callback, &true_errno);
+	if (ret) {
+		if (errno == EISDIR)
+			error("directory not empty: %s", path);
+		else
+			error("unable to move logfile %s to %s: %s",
+			      git_path(TMP_RENAMED_LOG), path,
+			      strerror(true_errno));
 	}
 
-	if (rename(git_path(TMP_RENAMED_LOG), path.buf)) {
-		if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
-			/*
-			 * rename(a, b) when b is an existing
-			 * directory ought to result in ISDIR, but
-			 * Solaris 5.8 gives ENOTDIR.  Sheesh.
-			 */
-			if (remove_empty_directories(&path)) {
-				error("Directory not empty: logs/%s", newrefname);
-				goto out;
-			}
-			goto retry;
-		} else if (errno == ENOENT && --attempts_remaining > 0) {
-			/*
-			 * Maybe another process just deleted one of
-			 * the directories in the path to newrefname.
-			 * Try again from the beginning.
-			 */
-			goto retry;
-		} else {
-			error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
-				newrefname, strerror(errno));
-			goto out;
-		}
-	}
-	ret = 0;
-out:
-	strbuf_release(&path);
+	free(path);
 	return ret;
 }
 
@@ -2616,7 +2596,7 @@
 		return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
 			oldrefname, strerror(errno));
 
-	if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
+	if (delete_ref(logmsg, oldrefname, orig_sha1, REF_NODEREF)) {
 		error("unable to delete old %s", oldrefname);
 		goto rollback;
 	}
@@ -2630,8 +2610,8 @@
 	 */
 	if (!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,
 			   sha1, NULL) &&
-	    delete_ref(newrefname, NULL, REF_NODEREF)) {
-		if (errno==EISDIR) {
+	    delete_ref(NULL, newrefname, NULL, REF_NODEREF)) {
+		if (errno == EISDIR) {
 			struct strbuf path = STRBUF_INIT;
 			int result;
 
@@ -2740,66 +2720,89 @@
 	return 0;
 }
 
-/*
- * Create a reflog for a ref.  If force_create = 0, the reflog will
- * only be created for certain refs (those for which
- * should_autocreate_reflog returns non-zero.  Otherwise, create it
- * regardless of the ref name.  Fill in *err and return -1 on failure.
- */
-static int log_ref_setup(const char *refname, struct strbuf *logfile, struct strbuf *err, int force_create)
+static int open_or_create_logfile(const char *path, void *cb)
 {
-	int logfd, oflags = O_APPEND | O_WRONLY;
+	int *fd = cb;
 
-	strbuf_git_path(logfile, "logs/%s", refname);
-	if (force_create || should_autocreate_reflog(refname)) {
-		if (safe_create_leading_directories(logfile->buf) < 0) {
-			strbuf_addf(err, "unable to create directory for '%s': "
-				    "%s", logfile->buf, strerror(errno));
-			return -1;
-		}
-		oflags |= O_CREAT;
-	}
-
-	logfd = open(logfile->buf, oflags, 0666);
-	if (logfd < 0) {
-		if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))
-			return 0;
-
-		if (errno == EISDIR) {
-			if (remove_empty_directories(logfile)) {
-				strbuf_addf(err, "there are still logs under "
-					    "'%s'", logfile->buf);
-				return -1;
-			}
-			logfd = open(logfile->buf, oflags, 0666);
-		}
-
-		if (logfd < 0) {
-			strbuf_addf(err, "unable to append to '%s': %s",
-				    logfile->buf, strerror(errno));
-			return -1;
-		}
-	}
-
-	adjust_shared_perm(logfile->buf);
-	close(logfd);
-	return 0;
+	*fd = open(path, O_APPEND | O_WRONLY | O_CREAT, 0666);
+	return (*fd < 0) ? -1 : 0;
 }
 
+/*
+ * Create a reflog for a ref. If force_create = 0, only create the
+ * reflog for certain refs (those for which should_autocreate_reflog
+ * returns non-zero). Otherwise, create it regardless of the reference
+ * name. If the logfile already existed or was created, return 0 and
+ * set *logfd to the file descriptor opened for appending to the file.
+ * If no logfile exists and we decided not to create one, return 0 and
+ * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and
+ * return -1.
+ */
+static int log_ref_setup(const char *refname, int force_create,
+			 int *logfd, struct strbuf *err)
+{
+	char *logfile = git_pathdup("logs/%s", refname);
+
+	if (force_create || should_autocreate_reflog(refname)) {
+		if (raceproof_create_file(logfile, open_or_create_logfile, logfd)) {
+			if (errno == ENOENT)
+				strbuf_addf(err, "unable to create directory for '%s': "
+					    "%s", logfile, strerror(errno));
+			else if (errno == EISDIR)
+				strbuf_addf(err, "there are still logs under '%s'",
+					    logfile);
+			else
+				strbuf_addf(err, "unable to append to '%s': %s",
+					    logfile, strerror(errno));
+
+			goto error;
+		}
+	} else {
+		*logfd = open(logfile, O_APPEND | O_WRONLY, 0666);
+		if (*logfd < 0) {
+			if (errno == ENOENT || errno == EISDIR) {
+				/*
+				 * The logfile doesn't already exist,
+				 * but that is not an error; it only
+				 * means that we won't write log
+				 * entries to it.
+				 */
+				;
+			} else {
+				strbuf_addf(err, "unable to append to '%s': %s",
+					    logfile, strerror(errno));
+				goto error;
+			}
+		}
+	}
+
+	if (*logfd >= 0)
+		adjust_shared_perm(logfile);
+
+	free(logfile);
+	return 0;
+
+error:
+	free(logfile);
+	return -1;
+}
 
 static int files_create_reflog(struct ref_store *ref_store,
 			       const char *refname, int force_create,
 			       struct strbuf *err)
 {
-	int ret;
-	struct strbuf sb = STRBUF_INIT;
+	int fd;
 
 	/* Check validity (but we don't need the result): */
 	files_downcast(ref_store, 0, "create_reflog");
 
-	ret = log_ref_setup(refname, &sb, err, force_create);
-	strbuf_release(&sb);
-	return ret;
+	if (log_ref_setup(refname, force_create, &fd, err))
+		return -1;
+
+	if (fd >= 0)
+		close(fd);
+
+	return 0;
 }
 
 static int log_ref_write_fd(int fd, const unsigned char *old_sha1,
@@ -2828,59 +2831,43 @@
 	return 0;
 }
 
-static int log_ref_write_1(const char *refname, const unsigned char *old_sha1,
-			   const unsigned char *new_sha1, const char *msg,
-			   struct strbuf *logfile, int flags,
-			   struct strbuf *err)
+int files_log_ref_write(const char *refname, const unsigned char *old_sha1,
+			const unsigned char *new_sha1, const char *msg,
+			int flags, struct strbuf *err)
 {
-	int logfd, result, oflags = O_APPEND | O_WRONLY;
+	int logfd, result;
 
 	if (log_all_ref_updates == LOG_REFS_UNSET)
 		log_all_ref_updates = is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL;
 
-	result = log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG);
+	result = log_ref_setup(refname, flags & REF_FORCE_CREATE_REFLOG,
+			       &logfd, err);
 
 	if (result)
 		return result;
 
-	logfd = open(logfile->buf, oflags);
 	if (logfd < 0)
 		return 0;
 	result = log_ref_write_fd(logfd, old_sha1, new_sha1,
 				  git_committer_info(0), msg);
 	if (result) {
-		strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,
-			    strerror(errno));
+		int save_errno = errno;
+
+		strbuf_addf(err, "unable to append to '%s': %s",
+			    git_path("logs/%s", refname), strerror(save_errno));
 		close(logfd);
 		return -1;
 	}
 	if (close(logfd)) {
-		strbuf_addf(err, "unable to append to '%s': %s", logfile->buf,
-			    strerror(errno));
+		int save_errno = errno;
+
+		strbuf_addf(err, "unable to append to '%s': %s",
+			    git_path("logs/%s", refname), strerror(save_errno));
 		return -1;
 	}
 	return 0;
 }
 
-static int log_ref_write(const char *refname, const unsigned char *old_sha1,
-			 const unsigned char *new_sha1, const char *msg,
-			 int flags, struct strbuf *err)
-{
-	return files_log_ref_write(refname, old_sha1, new_sha1, msg, flags,
-				   err);
-}
-
-int files_log_ref_write(const char *refname, const unsigned char *old_sha1,
-			const unsigned char *new_sha1, const char *msg,
-			int flags, struct strbuf *err)
-{
-	struct strbuf sb = STRBUF_INIT;
-	int ret = log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags,
-				  err);
-	strbuf_release(&sb);
-	return ret;
-}
-
 /*
  * Write sha1 into the open lockfile, then close the lockfile. On
  * errors, rollback the lockfile, fill in *err and
@@ -2930,10 +2917,11 @@
 			     const unsigned char *sha1, const char *logmsg,
 			     struct strbuf *err)
 {
-	assert_main_repository(&refs->base, "commit_ref_update");
+	files_assert_main_repository(refs, "commit_ref_update");
 
 	clear_loose_ref_cache(refs);
-	if (log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg, 0, err)) {
+	if (files_log_ref_write(lock->ref_name, lock->old_oid.hash, sha1,
+				logmsg, 0, err)) {
 		char *old_msg = strbuf_detach(err, NULL);
 		strbuf_addf(err, "cannot update the ref '%s': %s",
 			    lock->ref_name, old_msg);
@@ -2964,7 +2952,7 @@
 		if (head_ref && (head_flag & REF_ISSYMREF) &&
 		    !strcmp(head_ref, lock->ref_name)) {
 			struct strbuf log_err = STRBUF_INIT;
-			if (log_ref_write("HEAD", lock->old_oid.hash, sha1,
+			if (files_log_ref_write("HEAD", lock->old_oid.hash, sha1,
 					  logmsg, 0, &log_err)) {
 				error("%s", log_err.buf);
 				strbuf_release(&log_err);
@@ -3003,7 +2991,8 @@
 	struct strbuf err = STRBUF_INIT;
 	unsigned char new_sha1[20];
 	if (logmsg && !read_ref(target, new_sha1) &&
-	    log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg, 0, &err)) {
+	    files_log_ref_write(refname, lock->old_oid.hash, new_sha1,
+				logmsg, 0, &err)) {
 		error("%s", err.buf);
 		strbuf_release(&err);
 	}
@@ -3055,7 +3044,7 @@
 	return ret;
 }
 
-int set_worktree_head_symref(const char *gitdir, const char *target)
+int set_worktree_head_symref(const char *gitdir, const char *target, const char *logmsg)
 {
 	static struct lock_file head_lock;
 	struct ref_lock *lock;
@@ -3083,7 +3072,7 @@
 	lock->lk = &head_lock;
 	lock->ref_name = xstrdup(head_rel);
 
-	ret = create_symref_locked(lock, head_rel, target, NULL);
+	ret = create_symref_locked(lock, head_rel, target, logmsg);
 
 	unlock_ref(lock); /* will free lock */
 	strbuf_release(&head_path);
@@ -3113,16 +3102,17 @@
 
 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
 {
-	unsigned char osha1[20], nsha1[20];
+	struct object_id ooid, noid;
 	char *email_end, *message;
 	unsigned long timestamp;
 	int tz;
+	const char *p = sb->buf;
 
 	/* old SP new SP name <email> SP time TAB msg LF */
-	if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
-	    get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
-	    get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
-	    !(email_end = strchr(sb->buf + 82, '>')) ||
+	if (!sb->len || sb->buf[sb->len - 1] != '\n' ||
+	    parse_oid_hex(p, &ooid, &p) || *p++ != ' ' ||
+	    parse_oid_hex(p, &noid, &p) || *p++ != ' ' ||
+	    !(email_end = strchr(p, '>')) ||
 	    email_end[1] != ' ' ||
 	    !(timestamp = strtoul(email_end + 2, &message, 10)) ||
 	    !message || message[0] != ' ' ||
@@ -3136,7 +3126,7 @@
 		message += 6;
 	else
 		message += 7;
-	return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
+	return fn(&ooid, &noid, p, timestamp, tz, message, cb_data);
 }
 
 static char *find_beginning_of_line(char *bob, char *scan)
@@ -3560,7 +3550,7 @@
 	int ret;
 	struct ref_lock *lock;
 
-	assert_main_repository(&refs->base, "lock_ref_for_update");
+	files_assert_main_repository(refs, "lock_ref_for_update");
 
 	if ((update->flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1))
 		update->flags |= REF_DELETING;
@@ -3778,9 +3768,11 @@
 
 		if (update->flags & REF_NEEDS_COMMIT ||
 		    update->flags & REF_LOG_ONLY) {
-			if (log_ref_write(lock->ref_name, lock->old_oid.hash,
-					  update->new_sha1,
-					  update->msg, update->flags, err)) {
+			if (files_log_ref_write(lock->ref_name,
+						lock->old_oid.hash,
+						update->new_sha1,
+						update->msg, update->flags,
+						err)) {
 				char *old_msg = strbuf_detach(err, NULL);
 
 				strbuf_addf(err, "cannot update the ref '%s': %s",
@@ -3810,9 +3802,14 @@
 
 		if (update->flags & REF_DELETING &&
 		    !(update->flags & REF_LOG_ONLY)) {
-			if (delete_ref_loose(lock, update->type, err)) {
-				ret = TRANSACTION_GENERIC_ERROR;
-				goto cleanup;
+			if (!(update->type & REF_ISPACKED) ||
+			    update->type & REF_ISSYMREF) {
+				/* It is a loose reference. */
+				if (unlink_or_msg(git_path("%s", lock->ref_name), err)) {
+					ret = TRANSACTION_GENERIC_ERROR;
+					goto cleanup;
+				}
+				update->flags |= REF_DELETED_LOOSE;
 			}
 
 			if (!(update->flags & REF_ISPRUNING))
@@ -3825,16 +3822,38 @@
 		ret = TRANSACTION_GENERIC_ERROR;
 		goto cleanup;
 	}
-	for_each_string_list_item(ref_to_delete, &refs_to_delete)
-		unlink_or_warn(git_path("logs/%s", ref_to_delete->string));
+
+	/* Delete the reflogs of any references that were deleted: */
+	for_each_string_list_item(ref_to_delete, &refs_to_delete) {
+		if (!unlink_or_warn(git_path("logs/%s", ref_to_delete->string)))
+			try_remove_empty_parents(ref_to_delete->string,
+						 REMOVE_EMPTY_PARENTS_REFLOG);
+	}
+
 	clear_loose_ref_cache(refs);
 
 cleanup:
 	transaction->state = REF_TRANSACTION_CLOSED;
 
-	for (i = 0; i < transaction->nr; i++)
-		if (transaction->updates[i]->backend_data)
-			unlock_ref(transaction->updates[i]->backend_data);
+	for (i = 0; i < transaction->nr; i++) {
+		struct ref_update *update = transaction->updates[i];
+		struct ref_lock *lock = update->backend_data;
+
+		if (lock)
+			unlock_ref(lock);
+
+		if (update->flags & REF_DELETED_LOOSE) {
+			/*
+			 * The loose reference was deleted. Delete any
+			 * empty parent directories. (Note that this
+			 * can only work because we have already
+			 * removed the lockfile.)
+			 */
+			try_remove_empty_parents(update->refname,
+						 REMOVE_EMPTY_PARENTS_REF);
+		}
+	}
+
 	string_list_clear(&refs_to_delete, 0);
 	free(head_ref);
 	string_list_clear(&affected_refnames, 0);
@@ -3936,10 +3955,10 @@
 	reflog_expiry_should_prune_fn *should_prune_fn;
 	void *policy_cb;
 	FILE *newlog;
-	unsigned char last_kept_sha1[20];
+	struct object_id last_kept_oid;
 };
 
-static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+static int expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
 			     const char *email, unsigned long timestamp, int tz,
 			     const char *message, void *cb_data)
 {
@@ -3947,9 +3966,9 @@
 	struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;
 
 	if (cb->flags & EXPIRE_REFLOGS_REWRITE)
-		osha1 = cb->last_kept_sha1;
+		ooid = &cb->last_kept_oid;
 
-	if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,
+	if ((*cb->should_prune_fn)(ooid->hash, noid->hash, email, timestamp, tz,
 				   message, policy_cb)) {
 		if (!cb->newlog)
 			printf("would prune %s", message);
@@ -3958,9 +3977,9 @@
 	} else {
 		if (cb->newlog) {
 			fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s",
-				sha1_to_hex(osha1), sha1_to_hex(nsha1),
+				oid_to_hex(ooid), oid_to_hex(noid),
 				email, timestamp, tz, message);
-			hashcpy(cb->last_kept_sha1, nsha1);
+			oidcpy(&cb->last_kept_oid, noid);
 		}
 		if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
 			printf("keep %s", message);
@@ -4047,14 +4066,14 @@
 		 */
 		int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&
 			!(type & REF_ISSYMREF) &&
-			!is_null_sha1(cb.last_kept_sha1);
+			!is_null_oid(&cb.last_kept_oid);
 
 		if (close_lock_file(&reflog_lock)) {
 			status |= error("couldn't write %s: %s", log_file,
 					strerror(errno));
 		} else if (update &&
 			   (write_in_full(get_lock_file_fd(lock->lk),
-				sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
+				oid_to_hex(&cb.last_kept_oid), GIT_SHA1_HEXSZ) != GIT_SHA1_HEXSZ ||
 			    write_str_in_full(get_lock_file_fd(lock->lk), "\n") != 1 ||
 			    close_ref(lock) < 0)) {
 			status |= error("couldn't write %s",
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 25444cf..fa93c9a 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -56,17 +56,24 @@
 #define REF_UPDATE_VIA_HEAD 0x100
 
 /*
+ * Used as a flag in ref_update::flags when the loose reference has
+ * been deleted.
+ */
+#define REF_DELETED_LOOSE 0x200
+
+/*
  * Return true iff refname is minimally safe. "Safe" here means that
  * deleting a loose reference by this name will not do any damage, for
  * example by causing a file that is not a reference to be deleted.
  * This function does not check that the reference name is legal; for
  * that, use check_refname_format().
  *
- * We consider a refname that starts with "refs/" to be safe as long
- * as any ".." components that it might contain do not escape "refs/".
- * Names that do not start with "refs/" are considered safe iff they
- * consist entirely of upper case characters and '_' (like "HEAD" and
- * "MERGE_HEAD" but not "config" or "FOO/BAR").
+ * A refname that starts with "refs/" is considered safe iff it
+ * doesn't contain any "." or ".." components or consecutive '/'
+ * characters, end with '/', or (on Windows) contain any '\'
+ * characters. Names that do not start with "refs/" are considered
+ * safe iff they consist entirely of upper case characters and '_'
+ * (like "HEAD" and "MERGE_HEAD" but not "config" or "FOO/BAR").
  */
 int refname_is_safe(const char *refname);
 
@@ -155,8 +162,9 @@
 
 	/*
 	 * One or more of REF_HAVE_NEW, REF_HAVE_OLD, REF_NODEREF,
-	 * REF_DELETING, REF_ISPRUNING, REF_LOG_ONLY, and
-	 * REF_UPDATE_VIA_HEAD:
+	 * REF_DELETING, REF_ISPRUNING, REF_LOG_ONLY,
+	 * REF_UPDATE_VIA_HEAD, REF_NEEDS_COMMIT, and
+	 * REF_DELETED_LOOSE:
 	 */
 	unsigned int flags;
 
@@ -627,47 +635,14 @@
 struct ref_store {
 	/* The backend describing this ref_store's storage scheme: */
 	const struct ref_storage_be *be;
-
-	/*
-	 * The name of the submodule represented by this object, or
-	 * the empty string if it represents the main repository's
-	 * reference store:
-	 */
-	const char *submodule;
-
-	/*
-	 * Submodule reference store instances are stored in a linked
-	 * list using this pointer.
-	 */
-	struct ref_store *next;
 };
 
 /*
- * Fill in the generic part of refs for the specified submodule and
- * add it to our collection of reference stores.
+ * Fill in the generic part of refs and add it to our collection of
+ * reference stores.
  */
 void base_ref_store_init(struct ref_store *refs,
-			 const struct ref_storage_be *be,
-			 const char *submodule);
-
-/*
- * Create, record, and return a ref_store instance for the specified
- * submodule (or the main repository if submodule is NULL).
- *
- * For backwards compatibility, submodule=="" is treated the same as
- * submodule==NULL.
- */
-struct ref_store *ref_store_init(const char *submodule);
-
-/*
- * Return the ref_store instance for the specified submodule (or the
- * main repository if submodule is NULL). If that ref_store hasn't
- * been initialized yet, return NULL.
- *
- * For backwards compatibility, submodule=="" is treated the same as
- * submodule==NULL.
- */
-struct ref_store *lookup_ref_store(const char *submodule);
+			 const struct ref_storage_be *be);
 
 /*
  * Return the ref_store instance for the specified submodule. For the
@@ -681,10 +656,9 @@
  */
 struct ref_store *get_ref_store(const char *submodule);
 
-/*
- * Die if refs is for a submodule (i.e., not for the main repository).
- * caller is used in any necessary error messages.
- */
-void assert_main_repository(struct ref_store *refs, const char *caller);
+const char *resolve_ref_recursively(struct ref_store *refs,
+				    const char *refname,
+				    int resolve_flags,
+				    unsigned char *sha1, int *flags);
 
 #endif /* REFS_REFS_INTERNAL_H */
diff --git a/remote.c b/remote.c
index bf1bf23..9f83fe2 100644
--- a/remote.c
+++ b/remote.c
@@ -693,7 +693,7 @@
 		name = get_default(current_branch, &name_given);
 
 	ret = make_remote(name, 0);
-	if (valid_remote_nick(name)) {
+	if (valid_remote_nick(name) && have_git_dir()) {
 		if (!valid_remote(ret))
 			read_remotes_file(ret);
 		if (!valid_remote(ret))
diff --git a/remote.h b/remote.h
index a5bbbe0..dd8c517 100644
--- a/remote.h
+++ b/remote.h
@@ -89,8 +89,13 @@
 		force:1,
 		forced_update:1,
 		expect_old_sha1:1,
-		deletion:1,
-		matched:1;
+		deletion:1;
+
+	enum {
+		REF_NOT_MATCHED = 0, /* initial value */
+		REF_MATCHED,
+		REF_UNADVERTISED_NOT_ALLOWED
+	} match_status;
 
 	/*
 	 * Order is important here, as we write to FETCH_HEAD
diff --git a/revision.c b/revision.c
index b37dbec..7ff61ff 100644
--- a/revision.c
+++ b/revision.c
@@ -147,7 +147,7 @@
 		revs->no_walk = 0;
 	if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 		struct strbuf buf = STRBUF_INIT;
-		int len = interpret_branch_name(name, 0, &buf);
+		int len = interpret_branch_name(name, 0, &buf, 0);
 		int st;
 
 		if (0 < len && name[len] && buf.len)
@@ -1196,11 +1196,11 @@
 	for_each(submodule, handle_one_ref, &cb);
 }
 
-static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
+static void handle_one_reflog_commit(struct object_id *oid, void *cb_data)
 {
 	struct all_refs_cb *cb = cb_data;
-	if (!is_null_sha1(sha1)) {
-		struct object *o = parse_object(sha1);
+	if (!is_null_oid(oid)) {
+		struct object *o = parse_object(oid->hash);
 		if (o) {
 			o->flags |= cb->all_flags;
 			/* ??? CMDLINEFLAGS ??? */
@@ -1214,12 +1214,12 @@
 	}
 }
 
-static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+static int handle_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
 		const char *email, unsigned long timestamp, int tz,
 		const char *message, void *cb_data)
 {
-	handle_one_reflog_commit(osha1, cb_data);
-	handle_one_reflog_commit(nsha1, cb_data);
+	handle_one_reflog_commit(ooid, cb_data);
+	handle_one_reflog_commit(noid, cb_data);
 	return 0;
 }
 
diff --git a/send-pack.c b/send-pack.c
index 6195b43..d2d2a49 100644
--- a/send-pack.c
+++ b/send-pack.c
@@ -72,6 +72,7 @@
 	struct child_process po = CHILD_PROCESS_INIT;
 	FILE *po_in;
 	int i;
+	int rc;
 
 	i = 4;
 	if (args->use_thin_pack)
@@ -125,27 +126,44 @@
 		po.out = -1;
 	}
 
-	if (finish_command(&po))
+	rc = finish_command(&po);
+	if (rc) {
+		/*
+		 * For a normal non-zero exit, we assume pack-objects wrote
+		 * something useful to stderr. For death by signal, though,
+		 * we should mention it to the user. The exception is SIGPIPE
+		 * (141), because that's a normal occurence if the remote end
+		 * hangs up (and we'll report that by trying to read the unpack
+		 * status).
+		 */
+		if (rc > 128 && rc != 141)
+			error("pack-objects died of signal %d", rc - 128);
 		return -1;
+	}
+	return 0;
+}
+
+static int receive_unpack_status(int in)
+{
+	const char *line = packet_read_line(in, NULL);
+	if (!skip_prefix(line, "unpack ", &line))
+		return error(_("unable to parse remote unpack status: %s"), line);
+	if (strcmp(line, "ok"))
+		return error(_("remote unpack failed: %s"), line);
 	return 0;
 }
 
 static int receive_status(int in, struct ref *refs)
 {
 	struct ref *hint;
-	int ret = 0;
-	char *line = packet_read_line(in, NULL);
-	if (!starts_with(line, "unpack "))
-		return error("did not receive remote status");
-	if (strcmp(line, "unpack ok")) {
-		error("unpack failed: %s", line + 7);
-		ret = -1;
-	}
+	int ret;
+
 	hint = NULL;
+	ret = receive_unpack_status(in);
 	while (1) {
 		char *refname;
 		char *msg;
-		line = packet_read_line(in, NULL);
+		char *line = packet_read_line(in, NULL);
 		if (!line)
 			break;
 		if (!starts_with(line, "ok ") && !starts_with(line, "ng ")) {
@@ -557,6 +575,14 @@
 				close(out);
 			if (git_connection_is_socket(conn))
 				shutdown(fd[0], SHUT_WR);
+
+			/*
+			 * Do not even bother with the return value; we know we
+			 * are failing, and just want the error() side effects.
+			 */
+			if (status_report)
+				receive_unpack_status(in);
+
 			if (use_sideband) {
 				close(demux.out);
 				finish_async(&demux);
diff --git a/setup.c b/setup.c
index 98b8dee..64f922a 100644
--- a/setup.c
+++ b/setup.c
@@ -254,7 +254,7 @@
 		if (!is_absolute_path(data.buf))
 			strbuf_addf(&path, "%s/", gitdir);
 		strbuf_addbuf(&path, &data);
-		strbuf_addstr(sb, real_path(path.buf));
+		strbuf_add_real_path(sb, path.buf);
 		ret = 1;
 	} else {
 		strbuf_addstr(sb, gitdir);
@@ -699,7 +699,7 @@
 	/* --work-tree is set without --git-dir; use discovered one */
 	if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 		if (offset != cwd->len && !is_absolute_path(gitdir))
-			gitdir = real_pathdup(gitdir);
+			gitdir = real_pathdup(gitdir, 1);
 		if (chdir(cwd->buf))
 			die_errno("Could not come back to cwd");
 		return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
@@ -809,7 +809,7 @@
 		/* Keep entry but do not canonicalize it */
 		return 1;
 	} else {
-		char *real_path = real_pathdup(ceil);
+		char *real_path = real_pathdup(ceil, 0);
 		if (!real_path) {
 			return 0;
 		}
diff --git a/sha1_file.c b/sha1_file.c
index ec957db..29bbc5f 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -129,8 +129,10 @@
 		*slash = '\0';
 		if (!stat(path, &st)) {
 			/* path exists */
-			if (!S_ISDIR(st.st_mode))
+			if (!S_ISDIR(st.st_mode)) {
+				errno = ENOTDIR;
 				ret = SCLD_EXISTS;
+			}
 		} else if (mkdir(path, 0777)) {
 			if (errno == EEXIST &&
 			    !stat(path, &st) && S_ISDIR(st.st_mode))
@@ -158,13 +160,85 @@
 
 enum scld_error safe_create_leading_directories_const(const char *path)
 {
+	int save_errno;
 	/* path points to cache entries, so xstrdup before messing with it */
 	char *buf = xstrdup(path);
 	enum scld_error result = safe_create_leading_directories(buf);
+
+	save_errno = errno;
 	free(buf);
+	errno = save_errno;
 	return result;
 }
 
+int raceproof_create_file(const char *path, create_file_fn fn, void *cb)
+{
+	/*
+	 * The number of times we will try to remove empty directories
+	 * in the way of path. This is only 1 because if another
+	 * process is racily creating directories that conflict with
+	 * us, we don't want to fight against them.
+	 */
+	int remove_directories_remaining = 1;
+
+	/*
+	 * The number of times that we will try to create the
+	 * directories containing path. We are willing to attempt this
+	 * more than once, because another process could be trying to
+	 * clean up empty directories at the same time as we are
+	 * trying to create them.
+	 */
+	int create_directories_remaining = 3;
+
+	/* A scratch copy of path, filled lazily if we need it: */
+	struct strbuf path_copy = STRBUF_INIT;
+
+	int ret, save_errno;
+
+	/* Sanity check: */
+	assert(*path);
+
+retry_fn:
+	ret = fn(path, cb);
+	save_errno = errno;
+	if (!ret)
+		goto out;
+
+	if (errno == EISDIR && remove_directories_remaining-- > 0) {
+		/*
+		 * A directory is in the way. Maybe it is empty; try
+		 * to remove it:
+		 */
+		if (!path_copy.len)
+			strbuf_addstr(&path_copy, path);
+
+		if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY))
+			goto retry_fn;
+	} else if (errno == ENOENT && create_directories_remaining-- > 0) {
+		/*
+		 * Maybe the containing directory didn't exist, or
+		 * maybe it was just deleted by a process that is
+		 * racing with us to clean up empty directories. Try
+		 * to create it:
+		 */
+		enum scld_error scld_result;
+
+		if (!path_copy.len)
+			strbuf_addstr(&path_copy, path);
+
+		do {
+			scld_result = safe_create_leading_directories(path_copy.buf);
+			if (scld_result == SCLD_OK)
+				goto retry_fn;
+		} while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0);
+	}
+
+out:
+	strbuf_release(&path_copy);
+	errno = save_errno;
+	return ret;
+}
+
 static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1)
 {
 	int i;
@@ -593,7 +667,7 @@
  * either does not exist on disk, or has a stale mtime and may be subject to
  * pruning).
  */
-static int check_and_freshen_file(const char *fn, int freshen)
+int check_and_freshen_file(const char *fn, int freshen)
 {
 	if (access(fn, F_OK))
 		return 0;
@@ -2532,6 +2606,7 @@
 	while (delta_stack_nr) {
 		void *delta_data;
 		void *base = data;
+		void *external_base = NULL;
 		unsigned long delta_size, base_size = size;
 		int i;
 
@@ -2558,6 +2633,7 @@
 				      p->pack_name);
 				mark_bad_packed_object(p, base_sha1);
 				base = read_object(base_sha1, &type, &base_size);
+				external_base = base;
 			}
 		}
 
@@ -2576,6 +2652,7 @@
 			      "at offset %"PRIuMAX" from %s",
 			      (uintmax_t)curpos, p->pack_name);
 			data = NULL;
+			free(external_base);
 			continue;
 		}
 
@@ -2595,6 +2672,7 @@
 			error("failed to apply delta");
 
 		free(delta_data);
+		free(external_base);
 	}
 
 	*final_type = type;
@@ -2628,6 +2706,17 @@
 	}
 }
 
+const struct object_id *nth_packed_object_oid(struct object_id *oid,
+					      struct packed_git *p,
+					      uint32_t n)
+{
+	const unsigned char *hash = nth_packed_object_sha1(p, n);
+	if (!hash)
+		return NULL;
+	hashcpy(oid->hash, hash);
+	return oid;
+}
+
 void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
 {
 	const unsigned char *ptr = vptr;
@@ -3674,15 +3763,15 @@
 		strbuf_setlen(path, baselen);
 		strbuf_addf(path, "/%s", de->d_name);
 
-		if (strlen(de->d_name) == 38)  {
-			char hex[41];
-			unsigned char sha1[20];
+		if (strlen(de->d_name) == GIT_SHA1_HEXSZ - 2)  {
+			char hex[GIT_SHA1_HEXSZ+1];
+			struct object_id oid;
 
 			snprintf(hex, sizeof(hex), "%02x%s",
 				 subdir_nr, de->d_name);
-			if (!get_sha1_hex(hex, sha1)) {
+			if (!get_oid_hex(hex, &oid)) {
 				if (obj_cb) {
-					r = obj_cb(sha1, path->buf, data);
+					r = obj_cb(&oid, path->buf, data);
 					if (r)
 						break;
 				}
@@ -3788,13 +3877,13 @@
 	int r = 0;
 
 	for (i = 0; i < p->num_objects; i++) {
-		const unsigned char *sha1 = nth_packed_object_sha1(p, i);
+		struct object_id oid;
 
-		if (!sha1)
+		if (!nth_packed_object_oid(&oid, p, i))
 			return error("unable to get sha1 of object %u in %s",
 				     i, p->pack_name);
 
-		r = cb(sha1, p, i, data);
+		r = cb(&oid, p, i, data);
 		if (r)
 			break;
 	}
diff --git a/sha1_name.c b/sha1_name.c
index 73a915f..cda9e49 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -1051,7 +1051,7 @@
 	struct strbuf buf;
 };
 
-static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
+static int grab_nth_branch_switch(struct object_id *ooid, struct object_id *noid,
 				  const char *email, unsigned long timestamp, int tz,
 				  const char *message, void *cb_data)
 {
@@ -1176,7 +1176,8 @@
 	return 1;
 }
 
-static int reinterpret(const char *name, int namelen, int len, struct strbuf *buf)
+static int reinterpret(const char *name, int namelen, int len,
+		       struct strbuf *buf, unsigned allowed)
 {
 	/* we have extra data, which might need further processing */
 	struct strbuf tmp = STRBUF_INIT;
@@ -1184,7 +1185,7 @@
 	int ret;
 
 	strbuf_add(buf, name + len, namelen - len);
-	ret = interpret_branch_name(buf->buf, buf->len, &tmp);
+	ret = interpret_branch_name(buf->buf, buf->len, &tmp, allowed);
 	/* that data was not interpreted, remove our cruft */
 	if (ret < 0) {
 		strbuf_setlen(buf, used);
@@ -1205,11 +1206,27 @@
 	free(s);
 }
 
+static int branch_interpret_allowed(const char *refname, unsigned allowed)
+{
+	if (!allowed)
+		return 1;
+
+	if ((allowed & INTERPRET_BRANCH_LOCAL) &&
+	    starts_with(refname, "refs/heads/"))
+		return 1;
+	if ((allowed & INTERPRET_BRANCH_REMOTE) &&
+	    starts_with(refname, "refs/remotes/"))
+		return 1;
+
+	return 0;
+}
+
 static int interpret_branch_mark(const char *name, int namelen,
 				 int at, struct strbuf *buf,
 				 int (*get_mark)(const char *, int),
 				 const char *(*get_data)(struct branch *,
-							 struct strbuf *))
+							 struct strbuf *),
+				 unsigned allowed)
 {
 	int len;
 	struct branch *branch;
@@ -1234,64 +1251,55 @@
 	if (!value)
 		die("%s", err.buf);
 
+	if (!branch_interpret_allowed(value, allowed))
+		return -1;
+
 	set_shortened_ref(buf, value);
 	return len + at;
 }
 
-/*
- * This reads short-hand syntax that not only evaluates to a commit
- * object name, but also can act as if the end user spelled the name
- * of the branch from the command line.
- *
- * - "@{-N}" finds the name of the Nth previous branch we were on, and
- *   places the name of the branch in the given buf and returns the
- *   number of characters parsed if successful.
- *
- * - "<branch>@{upstream}" finds the name of the other ref that
- *   <branch> is configured to merge with (missing <branch> defaults
- *   to the current branch), and places the name of the branch in the
- *   given buf and returns the number of characters parsed if
- *   successful.
- *
- * If the input is not of the accepted format, it returns a negative
- * number to signal an error.
- *
- * If the input was ok but there are not N branch switches in the
- * reflog, it returns 0.
- */
-int interpret_branch_name(const char *name, int namelen, struct strbuf *buf)
+int interpret_branch_name(const char *name, int namelen, struct strbuf *buf,
+			  unsigned allowed)
 {
 	char *at;
 	const char *start;
-	int len = interpret_nth_prior_checkout(name, namelen, buf);
+	int len;
 
 	if (!namelen)
 		namelen = strlen(name);
 
-	if (!len) {
-		return len; /* syntax Ok, not enough switches */
-	} else if (len > 0) {
-		if (len == namelen)
-			return len; /* consumed all */
-		else
-			return reinterpret(name, namelen, len, buf);
+	if (!allowed || (allowed & INTERPRET_BRANCH_LOCAL)) {
+		len = interpret_nth_prior_checkout(name, namelen, buf);
+		if (!len) {
+			return len; /* syntax Ok, not enough switches */
+		} else if (len > 0) {
+			if (len == namelen)
+				return len; /* consumed all */
+			else
+				return reinterpret(name, namelen, len, buf, allowed);
+		}
 	}
 
 	for (start = name;
 	     (at = memchr(start, '@', namelen - (start - name)));
 	     start = at + 1) {
 
-		len = interpret_empty_at(name, namelen, at - name, buf);
-		if (len > 0)
-			return reinterpret(name, namelen, len, buf);
+		if (!allowed || (allowed & INTERPRET_BRANCH_HEAD)) {
+			len = interpret_empty_at(name, namelen, at - name, buf);
+			if (len > 0)
+				return reinterpret(name, namelen, len, buf,
+						   allowed);
+		}
 
 		len = interpret_branch_mark(name, namelen, at - name, buf,
-					    upstream_mark, branch_get_upstream);
+					    upstream_mark, branch_get_upstream,
+					    allowed);
 		if (len > 0)
 			return len;
 
 		len = interpret_branch_mark(name, namelen, at - name, buf,
-					    push_mark, branch_get_push);
+					    push_mark, branch_get_push,
+					    allowed);
 		if (len > 0)
 			return len;
 	}
@@ -1299,22 +1307,19 @@
 	return -1;
 }
 
-int strbuf_branchname(struct strbuf *sb, const char *name)
+void strbuf_branchname(struct strbuf *sb, const char *name, unsigned allowed)
 {
 	int len = strlen(name);
-	int used = interpret_branch_name(name, len, sb);
+	int used = interpret_branch_name(name, len, sb, allowed);
 
-	if (used == len)
-		return 0;
 	if (used < 0)
 		used = 0;
 	strbuf_add(sb, name + used, len - used);
-	return len;
 }
 
 int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
 {
-	strbuf_branchname(sb, name);
+	strbuf_branchname(sb, name, INTERPRET_BRANCH_LOCAL);
 	if (name[0] == '-')
 		return -1;
 	strbuf_splice(sb, 0, 0, "refs/heads/", 11);
diff --git a/split-index.c b/split-index.c
index 615f4ca..f519e60 100644
--- a/split-index.c
+++ b/split-index.c
@@ -317,3 +317,25 @@
 		istate->split_index->base->cache[new->index - 1] = new;
 	}
 }
+
+void add_split_index(struct index_state *istate)
+{
+	if (!istate->split_index) {
+		init_split_index(istate);
+		istate->cache_changed |= SPLIT_INDEX_ORDERED;
+	}
+}
+
+void remove_split_index(struct index_state *istate)
+{
+	if (istate->split_index) {
+		/*
+		 * can't discard_split_index(&the_index); because that
+		 * will destroy split_index->base->cache[], which may
+		 * be shared with the_index.cache[]. So yeah we're
+		 * leaking a bit here.
+		 */
+		istate->split_index = NULL;
+		istate->cache_changed |= SOMETHING_CHANGED;
+	}
+}
diff --git a/split-index.h b/split-index.h
index c1324f5..df91c1b 100644
--- a/split-index.h
+++ b/split-index.h
@@ -31,5 +31,7 @@
 void prepare_to_write_split_index(struct index_state *istate);
 void finish_writing_split_index(struct index_state *istate);
 void discard_split_index(struct index_state *istate);
+void add_split_index(struct index_state *istate);
+void remove_split_index(struct index_state *istate);
 
 #endif
diff --git a/strbuf.c b/strbuf.c
index 8fec657..ace58e7 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -707,6 +707,17 @@
 	strbuf_addstr(sb, path);
 }
 
+void strbuf_add_real_path(struct strbuf *sb, const char *path)
+{
+	if (sb->len) {
+		struct strbuf resolved = STRBUF_INIT;
+		strbuf_realpath(&resolved, path, 1);
+		strbuf_addbuf(sb, &resolved);
+		strbuf_release(&resolved);
+	} else
+		strbuf_realpath(sb, path, 1);
+}
+
 int printf_ln(const char *fmt, ...)
 {
 	int ret;
diff --git a/strbuf.h b/strbuf.h
index cf1b540..80047b1 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -441,6 +441,20 @@
  */
 extern void strbuf_add_absolute_path(struct strbuf *sb, const char *path);
 
+/**
+ * Canonize `path` (make it absolute, resolve symlinks, remove extra
+ * slashes) and append it to `sb`.  Die with an informative error
+ * message if there is a problem.
+ *
+ * The directory part of `path` (i.e., everything up to the last
+ * dir_sep) must denote a valid, existing directory, but the last
+ * component need not exist.
+ *
+ * Callers that don't mind links should use the more lightweight
+ * strbuf_add_absolute_path() instead.
+ */
+extern void strbuf_add_real_path(struct strbuf *sb, const char *path);
+
 
 /**
  * Normalize in-place the path contained in the strbuf. See
@@ -560,7 +574,26 @@
 	strbuf_complete(sb, '\n');
 }
 
-extern int strbuf_branchname(struct strbuf *sb, const char *name);
+/*
+ * Copy "name" to "sb", expanding any special @-marks as handled by
+ * interpret_branch_name(). The result is a non-qualified branch name
+ * (so "foo" or "origin/master" instead of "refs/heads/foo" or
+ * "refs/remotes/origin/master").
+ *
+ * Note that the resulting name may not be a syntactically valid refname.
+ *
+ * If "allowed" is non-zero, restrict the set of allowed expansions. See
+ * interpret_branch_name() for details.
+ */
+extern void strbuf_branchname(struct strbuf *sb, const char *name,
+			      unsigned allowed);
+
+/*
+ * Like strbuf_branchname() above, but confirm that the result is
+ * syntactically valid to be used as a local branch name in refs/heads/.
+ *
+ * The return value is "0" if the result is valid, and "-1" otherwise.
+ */
 extern int strbuf_check_branch_ref(struct strbuf *sb, const char *name);
 
 extern void strbuf_addstr_urlencode(struct strbuf *, const char *,
diff --git a/submodule.c b/submodule.c
index 3b98766..3200b7b 100644
--- a/submodule.c
+++ b/submodule.c
@@ -1403,7 +1403,7 @@
 		/* If it is an actual gitfile, it doesn't need migration. */
 		return;
 
-	real_old_git_dir = real_pathdup(old_git_dir);
+	real_old_git_dir = real_pathdup(old_git_dir, 1);
 
 	sub = submodule_from_path(null_sha1, path);
 	if (!sub)
@@ -1412,7 +1412,7 @@
 	new_git_dir = git_path("modules/%s", sub->name);
 	if (safe_create_leading_directories_const(new_git_dir) < 0)
 		die(_("could not create directory '%s'"), new_git_dir);
-	real_new_git_dir = real_pathdup(new_git_dir);
+	real_new_git_dir = real_pathdup(new_git_dir, 1);
 
 	if (!prefix)
 		prefix = get_super_prefix();
@@ -1472,14 +1472,14 @@
 		new_git_dir = git_path("modules/%s", sub->name);
 		if (safe_create_leading_directories_const(new_git_dir) < 0)
 			die(_("could not create directory '%s'"), new_git_dir);
-		real_new_git_dir = real_pathdup(new_git_dir);
+		real_new_git_dir = real_pathdup(new_git_dir, 1);
 		connect_work_tree_and_git_dir(path, real_new_git_dir);
 
 		free(real_new_git_dir);
 	} else {
 		/* Is it already absorbed into the superprojects git dir? */
-		char *real_sub_git_dir = real_pathdup(sub_git_dir);
-		char *real_common_git_dir = real_pathdup(get_git_common_dir());
+		char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
+		char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
 
 		if (!starts_with(real_sub_git_dir, real_common_git_dir))
 			relocate_single_git_dir_into_superproject(prefix, path);
@@ -1514,3 +1514,85 @@
 		strbuf_release(&sb);
 	}
 }
+
+const char *get_superproject_working_tree(void)
+{
+	struct child_process cp = CHILD_PROCESS_INIT;
+	struct strbuf sb = STRBUF_INIT;
+	const char *one_up = real_path_if_valid("../");
+	const char *cwd = xgetcwd();
+	const char *ret = NULL;
+	const char *subpath;
+	int code;
+	ssize_t len;
+
+	if (!is_inside_work_tree())
+		/*
+		 * FIXME:
+		 * We might have a superproject, but it is harder
+		 * to determine.
+		 */
+		return NULL;
+
+	if (!one_up)
+		return NULL;
+
+	subpath = relative_path(cwd, one_up, &sb);
+
+	prepare_submodule_repo_env(&cp.env_array);
+	argv_array_pop(&cp.env_array);
+
+	argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
+			"ls-files", "-z", "--stage", "--full-name", "--",
+			subpath, NULL);
+	strbuf_reset(&sb);
+
+	cp.no_stdin = 1;
+	cp.no_stderr = 1;
+	cp.out = -1;
+	cp.git_cmd = 1;
+
+	if (start_command(&cp))
+		die(_("could not start ls-files in .."));
+
+	len = strbuf_read(&sb, cp.out, PATH_MAX);
+	close(cp.out);
+
+	if (starts_with(sb.buf, "160000")) {
+		int super_sub_len;
+		int cwd_len = strlen(cwd);
+		char *super_sub, *super_wt;
+
+		/*
+		 * There is a superproject having this repo as a submodule.
+		 * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
+		 * We're only interested in the name after the tab.
+		 */
+		super_sub = strchr(sb.buf, '\t') + 1;
+		super_sub_len = sb.buf + sb.len - super_sub - 1;
+
+		if (super_sub_len > cwd_len ||
+		    strcmp(&cwd[cwd_len - super_sub_len], super_sub))
+			die (_("BUG: returned path string doesn't match cwd?"));
+
+		super_wt = xstrdup(cwd);
+		super_wt[cwd_len - super_sub_len] = '\0';
+
+		ret = real_path(super_wt);
+		free(super_wt);
+	}
+	strbuf_release(&sb);
+
+	code = finish_command(&cp);
+
+	if (code == 128)
+		/* '../' is not a git repository */
+		return NULL;
+	if (code == 0 && len == 0)
+		/* There is an unrelated git repository at '../' */
+		return NULL;
+	if (code)
+		die(_("ls-tree returned unexpected return code %d"), code);
+
+	return ret;
+}
diff --git a/submodule.h b/submodule.h
index 05ab674..c8a0c9c 100644
--- a/submodule.h
+++ b/submodule.h
@@ -93,4 +93,12 @@
 extern void absorb_git_dir_into_superproject(const char *prefix,
 					     const char *path,
 					     unsigned flags);
+
+/*
+ * Return the absolute path of the working tree of the superproject, which this
+ * project is a submodule of. If this repository is not a submodule of
+ * another repository, return NULL.
+ */
+extern const char *get_superproject_working_tree(void);
+
 #endif
diff --git a/t/gitweb-lib.sh b/t/gitweb-lib.sh
index d5dab5a..006d2a8 100644
--- a/t/gitweb-lib.sh
+++ b/t/gitweb-lib.sh
@@ -110,7 +110,12 @@
 }
 
 perl -MCGI -MCGI::Util -MCGI::Carp -e 0 >/dev/null 2>&1 || {
-	skip_all='skipping gitweb tests, CGI module unusable'
+	skip_all='skipping gitweb tests, CGI & CGI::Util & CGI::Carp modules not available'
+	test_done
+}
+
+perl -mTime::HiRes -e 0 >/dev/null 2>&1 || {
+	skip_all='skipping gitweb tests, Time::HiRes module not available'
 	test_done
 }
 
diff --git a/t/interop/.gitignore b/t/interop/.gitignore
new file mode 100644
index 0000000..49c78d3
--- /dev/null
+++ b/t/interop/.gitignore
@@ -0,0 +1,4 @@
+/trash directory*/
+/test-results/
+/.prove/
+/build/
diff --git a/t/interop/Makefile b/t/interop/Makefile
new file mode 100644
index 0000000..31a4bbc
--- /dev/null
+++ b/t/interop/Makefile
@@ -0,0 +1,16 @@
+-include ../../config.mak
+export GIT_TEST_OPTIONS
+
+SHELL_PATH ?= $(SHELL)
+SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
+T = $(sort $(wildcard i[0-9][0-9][0-9][0-9]-*.sh))
+
+all: $(T)
+
+$(T):
+	@echo "*** $@ ***"; '$(SHELL_PATH_SQ)' $@ $(GIT_TEST_OPTS)
+
+clean:
+	rm -rf build "trash directory".* test-results
+
+.PHONY: all clean $(T)
diff --git a/t/interop/README b/t/interop/README
new file mode 100644
index 0000000..72d42bd
--- /dev/null
+++ b/t/interop/README
@@ -0,0 +1,85 @@
+Git version interoperability tests
+==================================
+
+This directory has interoperability tests for git. Each script is
+similar to the normal test scripts found in t/, but with the added twist
+that two special versions of git, "git.a" and "git.b", are available in
+the PATH. Individual tests can then check the interaction between the
+two versions.
+
+When you add a feature that handles backwards compatibility between git
+versions, it's encouraged to add a test here to make sure it behaves as
+you expect.
+
+
+Running Tests
+-------------
+
+The easiest way to run tests is to say "make".  This runs all
+the tests against their default versions.
+
+You can run a single test like:
+
+    $ ./i0000-basic.sh
+    ok 1 - bare git is forbidden
+    ok 2 - git.a version (v1.6.6.3)
+    ok 3 - git.b version (v2.11.1)
+    # passed all 3 test(s)
+    1..3
+
+Each test contains default versions to run against. You may override
+these by setting `GIT_TEST_VERSION_A` and `GIT_TEST_VERSION_B` in the
+environment. Note that not all combinations will give sensible outcomes
+for all tests (e.g., a test checking for a specific old/new interaction
+may want something "old" enough" and something "new" enough; see
+individual tests for details).
+
+Version names should be resolvable as revisions in the current
+repository. They will be exported and built as needed using the
+config.mak files found at the root of your working tree.
+
+The exception is the special version "." which uses the currently-built
+contents of your working tree.
+
+You can set the following variables (in the environment or in your config.mak):
+
+    GIT_INTEROP_MAKE_OPTS
+	Options to pass to `make` when building a git version (e.g.,
+	`-j8`).
+
+You can also pass any command-line options taken by ordinary git tests (e.g.,
+"-v").
+
+
+Naming Tests
+------------
+
+The interop test files are named like:
+
+	iNNNN-short-description.sh
+
+where N is a decimal digit.  The same conventions for choosing NNNN as
+for normal tests apply.
+
+
+Writing Tests
+-------------
+
+An interop test script starts like a normal script, declaring a few
+variables and then including interop-lib.sh (which includes test-lib.sh).
+Besides test_description, you should also set the $VERSION_A and $VERSION_B
+variables to give the default versions to test against. See t0000-basic.sh for
+an example.
+
+You can then use test_expect_success as usual, with a few differences:
+
+  1. The special commands "git.a" and "git.b" correspond to the
+     two versions.
+
+  2. You cannot call a bare "git". This is to prevent accidents where
+     you meant "git.a" or "git.b".
+
+  3. The trash directory is _not_ a git repository by default. You
+     should create one with the appropriate version of git.
+
+At the end of the script, call test_done as usual.
diff --git a/t/interop/i0000-basic.sh b/t/interop/i0000-basic.sh
new file mode 100755
index 0000000..903e919
--- /dev/null
+++ b/t/interop/i0000-basic.sh
@@ -0,0 +1,27 @@
+#!/bin/sh
+
+# Note that this test only works on real version numbers,
+# as it depends on matching the output to "git version".
+VERSION_A=v1.6.6.3
+VERSION_B=v2.11.1
+
+test_description='sanity test interop library'
+. ./interop-lib.sh
+
+test_expect_success 'bare git is forbidden' '
+	test_must_fail git version
+'
+
+test_expect_success "git.a version ($VERSION_A)" '
+	echo git version ${VERSION_A#v} >expect &&
+	git.a version >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success "git.b version ($VERSION_B)" '
+	echo git version ${VERSION_B#v} >expect &&
+	git.b version >actual &&
+	test_cmp expect actual
+'
+
+test_done
diff --git a/t/interop/i5500-git-daemon.sh b/t/interop/i5500-git-daemon.sh
new file mode 100755
index 0000000..1daf694
--- /dev/null
+++ b/t/interop/i5500-git-daemon.sh
@@ -0,0 +1,41 @@
+#!/bin/sh
+
+VERSION_A=.
+VERSION_B=v1.0.0
+
+: ${LIB_GIT_DAEMON_PORT:=5500}
+LIB_GIT_DAEMON_COMMAND='git.a daemon'
+
+test_description='clone and fetch by older client'
+. ./interop-lib.sh
+. "$TEST_DIRECTORY"/lib-git-daemon.sh
+
+start_git_daemon --export-all
+
+repo=$GIT_DAEMON_DOCUMENT_ROOT_PATH/repo
+
+test_expect_success "create repo served by $VERSION_A" '
+	git.a init "$repo" &&
+	git.a -C "$repo" commit --allow-empty -m one
+'
+
+test_expect_success "clone with $VERSION_B" '
+	git.b clone "$GIT_DAEMON_URL/repo" child &&
+	echo one >expect &&
+	git.a -C child log -1 --format=%s >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success "fetch with $VERSION_B" '
+	git.a -C "$repo" commit --allow-empty -m two &&
+	(
+		cd child &&
+		git.b fetch
+	) &&
+	echo two >expect &&
+	git.a -C child log -1 --format=%s FETCH_HEAD >actual &&
+	test_cmp expect actual
+'
+
+stop_git_daemon
+test_done
diff --git a/t/interop/interop-lib.sh b/t/interop/interop-lib.sh
new file mode 100644
index 0000000..3e0a291
--- /dev/null
+++ b/t/interop/interop-lib.sh
@@ -0,0 +1,92 @@
+# Interoperability testing framework. Each script should source
+# this after setting default $VERSION_A and $VERSION_B variables.
+
+. ../../GIT-BUILD-OPTIONS
+INTEROP_ROOT=$(pwd)
+BUILD_ROOT=$INTEROP_ROOT/build
+
+build_version () {
+	if test -z "$1"
+	then
+		echo >&2 "error: test script did not set default versions"
+		return 1
+	fi
+
+	if test "$1" = "."
+	then
+		git rev-parse --show-toplevel
+		return 0
+	fi
+
+	sha1=$(git rev-parse "$1^{tree}") || return 1
+	dir=$BUILD_ROOT/$sha1
+
+	if test -e "$dir/.built"
+	then
+		echo "$dir"
+		return 0
+	fi
+
+	echo >&2 "==> Building $1..."
+
+	mkdir -p "$dir" || return 1
+
+	(cd "$(git rev-parse --show-cdup)" && git archive --format=tar "$sha1") |
+	(cd "$dir" && tar x) ||
+	return 1
+
+	for config in config.mak config.mak.autogen config.status
+	do
+		if test -e "$INTEROP_ROOT/../../$config"
+		then
+			cp "$INTEROP_ROOT/../../$config" "$dir/" || return 1
+		fi
+	done
+
+	(
+		cd "$dir" &&
+		make $GIT_INTEROP_MAKE_OPTS >&2 &&
+		touch .built
+	) || return 1
+
+	echo "$dir"
+}
+
+# Old versions of git don't have bin-wrappers, so let's give a rough emulation.
+wrap_git () {
+	write_script "$1" <<-EOF
+	GIT_EXEC_PATH="$2"
+	export GIT_EXEC_PATH
+	PATH="$2:\$PATH"
+	export GIT_EXEC_PATH
+	exec git "\$@"
+	EOF
+}
+
+generate_wrappers () {
+	mkdir -p .bin &&
+	wrap_git .bin/git.a "$DIR_A" &&
+	wrap_git .bin/git.b "$DIR_B" &&
+	write_script .bin/git <<-\EOF &&
+	echo >&2 fatal: test tried to run generic git
+	exit 1
+	EOF
+	PATH=$(pwd)/.bin:$PATH
+}
+
+VERSION_A=${GIT_TEST_VERSION_A:-$VERSION_A}
+VERSION_B=${GIT_TEST_VERSION_B:-$VERSION_B}
+
+if ! DIR_A=$(build_version "$VERSION_A") ||
+   ! DIR_B=$(build_version "$VERSION_B")
+then
+	echo >&2 "fatal: unable to build git versions"
+	exit 1
+fi
+
+TEST_DIRECTORY=$INTEROP_ROOT/..
+TEST_OUTPUT_DIRECTORY=$INTEROP_ROOT
+TEST_NO_CREATE_REPO=t
+. "$TEST_DIRECTORY"/test-lib.sh
+
+generate_wrappers || die "unable to set up interop test environment"
diff --git a/t/lib-git-daemon.sh b/t/lib-git-daemon.sh
index f9cbd47..987d406 100644
--- a/t/lib-git-daemon.sh
+++ b/t/lib-git-daemon.sh
@@ -46,7 +46,8 @@
 
 	say >&3 "Starting git daemon ..."
 	mkfifo git_daemon_output
-	git daemon --listen=127.0.0.1 --port="$LIB_GIT_DAEMON_PORT" \
+	${LIB_GIT_DAEMON_COMMAND:-git daemon} \
+		--listen=127.0.0.1 --port="$LIB_GIT_DAEMON_PORT" \
 		--reuseaddr --verbose \
 		--base-path="$GIT_DAEMON_DOCUMENT_ROOT_PATH" \
 		"$@" "$GIT_DAEMON_DOCUMENT_ROOT_PATH" \
diff --git a/t/lib-httpd/apache.conf b/t/lib-httpd/apache.conf
index 69174c6..0642ae7 100644
--- a/t/lib-httpd/apache.conf
+++ b/t/lib-httpd/apache.conf
@@ -133,6 +133,15 @@
 RewriteRule ^/loop-redir/x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-(.*) /$1 [R=302]
 RewriteRule ^/loop-redir/(.*)$ /loop-redir/x-$1 [R=302]
 
+# redir-to/502/x?y -> really-redir-to?path=502/x&qs=y which returns 502
+# redir-to/x?y -> really-redir-to?path=x&qs=y -> x?y
+RewriteCond %{QUERY_STRING} ^(.*)$
+RewriteRule ^/redir-to/(.*)$ /really-redir-to?path=$1&qs=%1 [R=302]
+RewriteCond %{QUERY_STRING} ^path=502/(.*)&qs=(.*)$
+RewriteRule ^/really-redir-to$ - [R=502,L]
+RewriteCond %{QUERY_STRING} ^path=(.*)&qs=(.*)$
+RewriteRule ^/really-redir-to$ /%1?%2 [R=302]
+
 # The first rule issues a client-side redirect to something
 # that _doesn't_ look like a git repo. The second rule is a
 # server-side rewrite, so that it turns out the odd-looking
diff --git a/t/perf/p0001-rev-list.sh b/t/perf/p0001-rev-list.sh
index 16359d5..ebf1724 100755
--- a/t/perf/p0001-rev-list.sh
+++ b/t/perf/p0001-rev-list.sh
@@ -15,7 +15,8 @@
 '
 
 test_expect_success 'create new unreferenced commit' '
-	commit=$(git commit-tree HEAD^{tree} -p HEAD)
+	commit=$(git commit-tree HEAD^{tree} -p HEAD) &&
+	test_export commit
 '
 
 test_perf 'rev-list $commit --not --all' '
diff --git a/t/perf/p7000-filter-branch.sh b/t/perf/p7000-filter-branch.sh
index 15ee5d1..b029586 100755
--- a/t/perf/p7000-filter-branch.sh
+++ b/t/perf/p7000-filter-branch.sh
@@ -16,4 +16,9 @@
 	git filter-branch -f base..HEAD
 '
 
+test_perf 'noop prune-empty' '
+	git checkout --detach tip &&
+	git filter-branch -f --prune-empty base..HEAD
+'
+
 test_done
diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
index 46f08ee..ab4b8b0 100644
--- a/t/perf/perf-lib.sh
+++ b/t/perf/perf-lib.sh
@@ -83,7 +83,7 @@
 	error "bug in the test script: not 2 parameters to test-create-repo"
 	repo="$1"
 	source="$2"
-	source_git="$(git -C "$source" rev-parse --git-dir)"
+	source_git="$("$MODERN_GIT" -C "$source" rev-parse --git-dir)"
 	objects_dir="$("$MODERN_GIT" -C "$source" rev-parse --git-path objects)"
 	mkdir -p "$repo/.git"
 	(
@@ -102,7 +102,7 @@
 	) &&
 	(
 		cd "$repo" &&
-		git init -q && {
+		"$MODERN_GIT" init -q && {
 			test_have_prereq SYMLINKS ||
 			git config core.symlinks false
 		} &&
diff --git a/t/perf/run b/t/perf/run
index e8adeda..c788d71 100755
--- a/t/perf/run
+++ b/t/perf/run
@@ -63,6 +63,9 @@
 		unset GIT_TEST_INSTALLED
 	else
 		GIT_TEST_INSTALLED="$mydir/bin-wrappers"
+		# Older versions of git lacked bin-wrappers; fallback to the
+		# files in the root.
+		test -d "$GIT_TEST_INSTALLED" || GIT_TEST_INSTALLED=$mydir
 		export GIT_TEST_INSTALLED
 	fi
 	run_one_dir "$@"
diff --git a/t/t0003-attributes.sh b/t/t0003-attributes.sh
index f0fbb42..f19ae4f 100755
--- a/t/t0003-attributes.sh
+++ b/t/t0003-attributes.sh
@@ -13,10 +13,31 @@
 	test_line_count = 0 err
 }
 
+attr_check_quote () {
+
+	path="$1"
+	quoted_path="$2"
+	expect="$3"
+
+	git check-attr test -- "$path" >actual &&
+	echo "\"$quoted_path\": test: $expect" >expect &&
+	test_cmp expect actual
+
+}
+
+test_expect_success 'open-quoted pathname' '
+	echo "\"a test=a" >.gitattributes &&
+	test_must_fail attr_check a a
+'
+
+
 test_expect_success 'setup' '
 	mkdir -p a/b/d a/c b &&
 	(
 		echo "[attr]notest !test"
+		echo "\" d \"	test=d"
+		echo " e	test=e"
+		echo " e\"	test=e"
 		echo "f	test=f"
 		echo "a/i test=a/i"
 		echo "onoff test -test"
@@ -69,6 +90,11 @@
 '
 
 test_expect_success 'attribute test' '
+
+	attr_check " d " d &&
+	attr_check e e &&
+	attr_check_quote e\" e\\\" e &&
+
 	attr_check f f &&
 	attr_check a/f f &&
 	attr_check a/c/f f &&
diff --git a/t/t0100-previous.sh b/t/t0100-previous.sh
index e0a6940..58c0b7e 100755
--- a/t/t0100-previous.sh
+++ b/t/t0100-previous.sh
@@ -56,5 +56,13 @@
 	test_must_fail git merge @{-100}
 '
 
+test_expect_success 'log -g @{-1}' '
+	git checkout -b last_branch &&
+	git checkout -b new_branch &&
+	echo "last_branch@{0}" >expect &&
+	git log -g --format=%gd @{-1} >actual &&
+	test_cmp expect actual
+'
+
 test_done
 
diff --git a/t/t1300-repo-config.sh b/t/t1300-repo-config.sh
index 923bfc5..afcca0d 100755
--- a/t/t1300-repo-config.sh
+++ b/t/t1300-repo-config.sh
@@ -1097,6 +1097,68 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'last one wins: two level vars' '
+
+	# sec.var and sec.VAR are the same variable, as the first
+	# and the last level of a configuration variable name is
+	# case insensitive.
+
+	echo VAL >expect &&
+
+	git -c sec.var=val -c sec.VAR=VAL config --get sec.var >actual &&
+	test_cmp expect actual &&
+	git -c SEC.var=val -c sec.var=VAL config --get sec.var >actual &&
+	test_cmp expect actual &&
+
+	git -c sec.var=val -c sec.VAR=VAL config --get SEC.var >actual &&
+	test_cmp expect actual &&
+	git -c SEC.var=val -c sec.var=VAL config --get sec.VAR >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'last one wins: three level vars' '
+
+	# v.a.r and v.A.r are not the same variable, as the middle
+	# level of a three-level configuration variable name is
+	# case sensitive.
+
+	echo val >expect &&
+	git -c v.a.r=val -c v.A.r=VAL config --get v.a.r >actual &&
+	test_cmp expect actual &&
+	git -c v.a.r=val -c v.A.r=VAL config --get V.a.R >actual &&
+	test_cmp expect actual &&
+
+	# v.a.r and V.a.R are the same variable, as the first
+	# and the last level of a configuration variable name is
+	# case insensitive.
+
+	echo VAL >expect &&
+	git -c v.a.r=val -c v.a.R=VAL config --get v.a.r >actual &&
+	test_cmp expect actual &&
+	git -c v.a.r=val -c V.a.r=VAL config --get v.a.r >actual &&
+	test_cmp expect actual &&
+	git -c v.a.r=val -c v.a.R=VAL config --get V.a.R >actual &&
+	test_cmp expect actual &&
+	git -c v.a.r=val -c V.a.r=VAL config --get V.a.R >actual &&
+	test_cmp expect actual
+'
+
+for VAR in a .a a. a.0b a."b c". a."b c".0d
+do
+	test_expect_success "git -c $VAR=VAL rejects invalid '$VAR'" '
+		test_must_fail git -c "$VAR=VAL" config -l
+	'
+done
+
+for VAR in a.b a."b c".d
+do
+	test_expect_success "git -c $VAR=VAL works with valid '$VAR'" '
+		echo VAL >expect &&
+		git -c "$VAR=VAL" config --get "$VAR" >actual &&
+		test_cmp expect actual
+	'
+done
+
 test_expect_success 'git -c is not confused by empty environment' '
 	GIT_CONFIG_PARAMETERS="" git -c x.one=1 config --list
 '
@@ -1177,6 +1239,111 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'urlmatch favors more specific URLs' '
+	cat >.git/config <<-\EOF &&
+	[http "https://example.com/"]
+		cookieFile = /tmp/root.txt
+	[http "https://example.com/subdirectory"]
+		cookieFile = /tmp/subdirectory.txt
+	[http "https://user@example.com/"]
+		cookieFile = /tmp/user.txt
+	[http "https://averylonguser@example.com/"]
+		cookieFile = /tmp/averylonguser.txt
+	[http "https://preceding.example.com"]
+		cookieFile = /tmp/preceding.txt
+	[http "https://*.example.com"]
+		cookieFile = /tmp/wildcard.txt
+	[http "https://*.example.com/wildcardwithsubdomain"]
+		cookieFile = /tmp/wildcardwithsubdomain.txt
+	[http "https://trailing.example.com"]
+		cookieFile = /tmp/trailing.txt
+	[http "https://user@*.example.com/"]
+		cookieFile = /tmp/wildcardwithuser.txt
+	[http "https://sub.example.com/"]
+		cookieFile = /tmp/sub.txt
+	EOF
+
+	echo http.cookiefile /tmp/root.txt >expect &&
+	git config --get-urlmatch HTTP https://example.com >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/subdirectory.txt >expect &&
+	git config --get-urlmatch HTTP https://example.com/subdirectory >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/subdirectory.txt >expect &&
+	git config --get-urlmatch HTTP https://example.com/subdirectory/nested >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/user.txt >expect &&
+	git config --get-urlmatch HTTP https://user@example.com/ >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/subdirectory.txt >expect &&
+	git config --get-urlmatch HTTP https://averylonguser@example.com/subdirectory >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/preceding.txt >expect &&
+	git config --get-urlmatch HTTP https://preceding.example.com >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/wildcard.txt >expect &&
+	git config --get-urlmatch HTTP https://wildcard.example.com >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/sub.txt >expect &&
+	git config --get-urlmatch HTTP https://sub.example.com/wildcardwithsubdomain >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/trailing.txt >expect &&
+	git config --get-urlmatch HTTP https://trailing.example.com >actual &&
+	test_cmp expect actual &&
+
+	echo http.cookiefile /tmp/sub.txt >expect &&
+	git config --get-urlmatch HTTP https://user@sub.example.com >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'urlmatch with wildcard' '
+	cat >.git/config <<-\EOF &&
+	[http]
+		sslVerify
+	[http "https://*.example.com"]
+		sslVerify = false
+		cookieFile = /tmp/cookie.txt
+	EOF
+
+	test_expect_code 1 git config --bool --get-urlmatch doesnt.exist https://good.example.com >actual &&
+	test_must_be_empty actual &&
+
+	echo true >expect &&
+	git config --bool --get-urlmatch http.SSLverify https://example.com >actual &&
+	test_cmp expect actual &&
+
+	echo true >expect &&
+	git config --bool --get-urlmatch http.SSLverify https://good-example.com >actual &&
+	test_cmp expect actual &&
+
+	echo true >expect &&
+	git config --bool --get-urlmatch http.sslverify https://deep.nested.example.com >actual &&
+	test_cmp expect actual &&
+
+	echo false >expect &&
+	git config --bool --get-urlmatch http.sslverify https://good.example.com >actual &&
+	test_cmp expect actual &&
+
+	{
+		echo http.cookiefile /tmp/cookie.txt &&
+		echo http.sslverify false
+	} >expect &&
+	git config --get-urlmatch HTTP https://good.example.com >actual &&
+	test_cmp expect actual &&
+
+	echo http.sslverify >expect &&
+	git config --get-urlmatch HTTP https://more.example.com.au >actual &&
+	test_cmp expect actual
+'
+
 # good section hygiene
 test_expect_failure 'unsetting the last key in a section removes header' '
 	cat >.git/config <<-\EOF &&
diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index b0ffc0b..8254223 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -85,6 +85,24 @@
 '
 rm -f .git/$m
 
+test_expect_success "deleting current branch adds message to HEAD's log" '
+	git update-ref $m $A &&
+	git symbolic-ref HEAD $m &&
+	git update-ref -m delete-$m -d $m &&
+	! test -f .git/$m &&
+	grep "delete-$m$" .git/logs/HEAD
+'
+rm -f .git/$m
+
+test_expect_success "deleting by HEAD adds message to HEAD's log" '
+	git update-ref $m $A &&
+	git symbolic-ref HEAD $m &&
+	git update-ref -m delete-by-head -d HEAD &&
+	! test -f .git/$m &&
+	grep "delete-by-head$" .git/logs/HEAD
+'
+rm -f .git/$m
+
 test_expect_success 'update-ref does not create reflogs by default' '
 	test_when_finished "git update-ref -d $outside" &&
 	git update-ref $outside $A &&
@@ -256,6 +274,33 @@
 	 git update-ref HEAD'" $A &&
 	 test $A"' = $(cat .git/'"$m"')'
 
+test_expect_success "empty directory removal" '
+	git branch d1/d2/r1 HEAD &&
+	git branch d1/r2 HEAD &&
+	test -f .git/refs/heads/d1/d2/r1 &&
+	test -f .git/logs/refs/heads/d1/d2/r1 &&
+	git branch -d d1/d2/r1 &&
+	! test -e .git/refs/heads/d1/d2 &&
+	! test -e .git/logs/refs/heads/d1/d2 &&
+	test -f .git/refs/heads/d1/r2 &&
+	test -f .git/logs/refs/heads/d1/r2
+'
+
+test_expect_success "symref empty directory removal" '
+	git branch e1/e2/r1 HEAD &&
+	git branch e1/r2 HEAD &&
+	git checkout e1/e2/r1 &&
+	test_when_finished "git checkout master" &&
+	test -f .git/refs/heads/e1/e2/r1 &&
+	test -f .git/logs/refs/heads/e1/e2/r1 &&
+	git update-ref -d HEAD &&
+	! test -e .git/refs/heads/e1/e2 &&
+	! test -e .git/logs/refs/heads/e1/e2 &&
+	test -f .git/refs/heads/e1/r2 &&
+	test -f .git/logs/refs/heads/e1/r2 &&
+	test -f .git/logs/HEAD
+'
+
 cat >expect <<EOF
 $Z $A $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150200 +0000	Initial Creation
 $A $B $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150260 +0000	Switch
diff --git a/t/t1500-rev-parse.sh b/t/t1500-rev-parse.sh
index 038e24c..03d3c7f 100755
--- a/t/t1500-rev-parse.sh
+++ b/t/t1500-rev-parse.sh
@@ -3,7 +3,7 @@
 test_description='test git rev-parse'
 . ./test-lib.sh
 
-# usage: [options] label is-bare is-inside-git is-inside-work prefix git-dir
+# usage: [options] label is-bare is-inside-git is-inside-work prefix git-dir absolute-git-dir
 test_rev_parse () {
 	d=
 	bare=
@@ -29,7 +29,8 @@
 		 --is-inside-git-dir \
 		 --is-inside-work-tree \
 		 --show-prefix \
-		 --git-dir
+		 --git-dir \
+		 --absolute-git-dir
 	do
 		test $# -eq 0 && break
 		expect="$1"
@@ -62,29 +63,71 @@
 	cp -R .git repo.git
 '
 
-test_rev_parse toplevel false false true '' .git
+test_rev_parse toplevel false false true '' .git "$ROOT/.git"
 
-test_rev_parse -C .git .git/ false true false '' .
-test_rev_parse -C .git/objects .git/objects/ false true false '' "$ROOT/.git"
+test_rev_parse -C .git .git/ false true false '' . "$ROOT/.git"
+test_rev_parse -C .git/objects .git/objects/ false true false '' "$ROOT/.git" "$ROOT/.git"
 
-test_rev_parse -C sub/dir subdirectory false false true sub/dir/ "$ROOT/.git"
+test_rev_parse -C sub/dir subdirectory false false true sub/dir/ "$ROOT/.git" "$ROOT/.git"
 
 test_rev_parse -b t 'core.bare = true' true false false
 
 test_rev_parse -b u 'core.bare undefined' false false true
 
 
-test_rev_parse -C work -g ../.git -b f 'GIT_DIR=../.git, core.bare = false' false false true ''
+test_rev_parse -C work -g ../.git -b f 'GIT_DIR=../.git, core.bare = false' false false true '' "../.git" "$ROOT/.git"
 
 test_rev_parse -C work -g ../.git -b t 'GIT_DIR=../.git, core.bare = true' true false false ''
 
 test_rev_parse -C work -g ../.git -b u 'GIT_DIR=../.git, core.bare undefined' false false true ''
 
 
-test_rev_parse -C work -g ../repo.git -b f 'GIT_DIR=../repo.git, core.bare = false' false false true ''
+test_rev_parse -C work -g ../repo.git -b f 'GIT_DIR=../repo.git, core.bare = false' false false true '' "../repo.git" "$ROOT/repo.git"
 
 test_rev_parse -C work -g ../repo.git -b t 'GIT_DIR=../repo.git, core.bare = true' true false false ''
 
 test_rev_parse -C work -g ../repo.git -b u 'GIT_DIR=../repo.git, core.bare undefined' false false true ''
 
+test_expect_success 'git-common-dir from worktree root' '
+	echo .git >expect &&
+	git rev-parse --git-common-dir >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git-common-dir inside sub-dir' '
+	mkdir -p path/to/child &&
+	test_when_finished "rm -rf path" &&
+	echo "$(git -C path/to/child rev-parse --show-cdup).git" >expect &&
+	git -C path/to/child rev-parse --git-common-dir >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git-path from worktree root' '
+	echo .git/objects >expect &&
+	git rev-parse --git-path objects >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git-path inside sub-dir' '
+	mkdir -p path/to/child &&
+	test_when_finished "rm -rf path" &&
+	echo "$(git -C path/to/child rev-parse --show-cdup).git/objects" >expect &&
+	git -C path/to/child rev-parse --git-path objects >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'showing the superproject correctly' '
+	git rev-parse --show-superproject-working-tree >out &&
+	test_must_be_empty out &&
+
+	test_create_repo super &&
+	test_commit -C super test_commit &&
+	test_create_repo sub &&
+	test_commit -C sub test_commit &&
+	git -C super submodule add ../sub dir/sub &&
+	echo $(pwd)/super >expect  &&
+	git -C super/dir/sub rev-parse --show-superproject-working-tree >out &&
+	test_cmp expect out
+'
+
 test_done
diff --git a/t/t1501-work-tree.sh b/t/t1501-work-tree.sh
index cc5b870..b06210e 100755
--- a/t/t1501-work-tree.sh
+++ b/t/t1501-work-tree.sh
@@ -423,4 +423,12 @@
 	)
 '
 
+test_expect_success 'error out gracefully on invalid $GIT_WORK_TREE' '
+	(
+		GIT_WORK_TREE=/.invalid/work/tree &&
+		export GIT_WORK_TREE &&
+		test_expect_code 128 git rev-parse
+	)
+'
+
 test_done
diff --git a/t/t1700-split-index.sh b/t/t1700-split-index.sh
index 292a072..af3ec0d 100755
--- a/t/t1700-split-index.sh
+++ b/t/t1700-split-index.sh
@@ -8,6 +8,7 @@
 sane_unset GIT_TEST_SPLIT_INDEX
 
 test_expect_success 'enable split index' '
+	git config splitIndex.maxPercentChange 100 &&
 	git update-index --split-index &&
 	test-dump-split-index .git/index >actual &&
 	indexversion=$(test-index-version <.git/index) &&
@@ -19,12 +20,12 @@
 		own=8299b0bcd1ac364e5f1d7768efb62fa2da79a339
 		base=39d890139ee5356c7ef572216cebcd27aa41f9df
 	fi &&
-	cat >expect <<EOF &&
-own $own
-base $base
-replacements:
-deletions:
-EOF
+	cat >expect <<-EOF &&
+	own $own
+	base $base
+	replacements:
+	deletions:
+	EOF
 	test_cmp expect actual
 '
 
@@ -32,51 +33,51 @@
 	: >one &&
 	git update-index --add one &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 $EMPTY_BLOB 0	one
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 $EMPTY_BLOB 0	one
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	cat >expect <<EOF &&
-base $base
-100644 $EMPTY_BLOB 0	one
-replacements:
-deletions:
-EOF
+	cat >expect <<-EOF &&
+	base $base
+	100644 $EMPTY_BLOB 0	one
+	replacements:
+	deletions:
+	EOF
 	test_cmp expect actual
 '
 
 test_expect_success 'disable split index' '
 	git update-index --no-split-index &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 $EMPTY_BLOB 0	one
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 $EMPTY_BLOB 0	one
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	BASE=$(test-dump-split-index .git/index | grep "^own" | sed "s/own/base/") &&
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	cat >expect <<EOF &&
-not a split index
-EOF
+	cat >expect <<-EOF &&
+	not a split index
+	EOF
 	test_cmp expect actual
 '
 
 test_expect_success 'enable split index again, "one" now belongs to base index"' '
 	git update-index --split-index &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 $EMPTY_BLOB 0	one
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 $EMPTY_BLOB 0	one
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	cat >expect <<EOF &&
-$BASE
-replacements:
-deletions:
-EOF
+	cat >expect <<-EOF &&
+	$BASE
+	replacements:
+	deletions:
+	EOF
 	test_cmp expect actual
 '
 
@@ -84,18 +85,18 @@
 	echo modified >one &&
 	git update-index one &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0	one
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0	one
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	q_to_tab >expect <<EOF &&
-$BASE
-100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0Q
-replacements: 0
-deletions:
-EOF
+	q_to_tab >expect <<-EOF &&
+	$BASE
+	100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0Q
+	replacements: 0
+	deletions:
+	EOF
 	test_cmp expect actual
 '
 
@@ -103,54 +104,54 @@
 	: >two &&
 	git update-index --add two &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0	one
-100644 $EMPTY_BLOB 0	two
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0	one
+	100644 $EMPTY_BLOB 0	two
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	q_to_tab >expect <<EOF &&
-$BASE
-100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0Q
-100644 $EMPTY_BLOB 0	two
-replacements: 0
-deletions:
-EOF
+	q_to_tab >expect <<-EOF &&
+	$BASE
+	100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0Q
+	100644 $EMPTY_BLOB 0	two
+	replacements: 0
+	deletions:
+	EOF
 	test_cmp expect actual
 '
 
 test_expect_success 'remove file not in base index' '
 	git update-index --force-remove two &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0	one
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0	one
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	q_to_tab >expect <<EOF &&
-$BASE
-100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0Q
-replacements: 0
-deletions:
-EOF
+	q_to_tab >expect <<-EOF &&
+	$BASE
+	100644 2e0996000b7e9019eabcad29391bf0f5c7702f0b 0Q
+	replacements: 0
+	deletions:
+	EOF
 	test_cmp expect actual
 '
 
 test_expect_success 'remove file in base index' '
 	git update-index --force-remove one &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-EOF
+	cat >ls-files.expect <<-EOF &&
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	cat >expect <<EOF &&
-$BASE
-replacements:
-deletions: 0
-EOF
+	cat >expect <<-EOF &&
+	$BASE
+	replacements:
+	deletions: 0
+	EOF
 	test_cmp expect actual
 '
 
@@ -158,18 +159,18 @@
 	: >one &&
 	git update-index --add one &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 $EMPTY_BLOB 0	one
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 $EMPTY_BLOB 0	one
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	cat >expect <<EOF &&
-$BASE
-100644 $EMPTY_BLOB 0	one
-replacements:
-deletions: 0
-EOF
+	cat >expect <<-EOF &&
+	$BASE
+	100644 $EMPTY_BLOB 0	one
+	replacements:
+	deletions: 0
+	EOF
 	test_cmp expect actual
 '
 
@@ -177,27 +178,196 @@
 	: >two &&
 	git update-index --add two &&
 	git ls-files --stage >actual &&
-	cat >expect <<EOF &&
-100644 $EMPTY_BLOB 0	one
-100644 $EMPTY_BLOB 0	two
-EOF
+	cat >expect <<-EOF &&
+	100644 $EMPTY_BLOB 0	one
+	100644 $EMPTY_BLOB 0	two
+	EOF
 	test_cmp expect actual
 '
 
 test_expect_success 'unify index, two files remain' '
 	git update-index --no-split-index &&
 	git ls-files --stage >ls-files.actual &&
-	cat >ls-files.expect <<EOF &&
-100644 $EMPTY_BLOB 0	one
-100644 $EMPTY_BLOB 0	two
-EOF
+	cat >ls-files.expect <<-EOF &&
+	100644 $EMPTY_BLOB 0	one
+	100644 $EMPTY_BLOB 0	two
+	EOF
 	test_cmp ls-files.expect ls-files.actual &&
 
 	test-dump-split-index .git/index | sed "/^own/d" >actual &&
-	cat >expect <<EOF &&
-not a split index
-EOF
+	cat >expect <<-EOF &&
+	not a split index
+	EOF
 	test_cmp expect actual
 '
 
+test_expect_success 'rev-parse --shared-index-path' '
+	test_create_repo split-index &&
+	(
+		cd split-index &&
+		git update-index --split-index &&
+		echo .git/sharedindex* >expect &&
+		git rev-parse --shared-index-path >actual &&
+		test_cmp expect actual &&
+		mkdir subdirectory &&
+		cd subdirectory &&
+		echo ../.git/sharedindex* >expect &&
+		git rev-parse --shared-index-path >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'set core.splitIndex config variable to true' '
+	git config core.splitIndex true &&
+	: >three &&
+	git update-index --add three &&
+	git ls-files --stage >ls-files.actual &&
+	cat >ls-files.expect <<-EOF &&
+	100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0	one
+	100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0	three
+	100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0	two
+	EOF
+	test_cmp ls-files.expect ls-files.actual &&
+	BASE=$(test-dump-split-index .git/index | grep "^base") &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	$BASE
+	replacements:
+	deletions:
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'set core.splitIndex config variable to false' '
+	git config core.splitIndex false &&
+	git update-index --force-remove three &&
+	git ls-files --stage >ls-files.actual &&
+	cat >ls-files.expect <<-EOF &&
+	100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0	one
+	100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0	two
+	EOF
+	test_cmp ls-files.expect ls-files.actual &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	not a split index
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'set core.splitIndex config variable to true' '
+	git config core.splitIndex true &&
+	: >three &&
+	git update-index --add three &&
+	BASE=$(test-dump-split-index .git/index | grep "^base") &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	$BASE
+	replacements:
+	deletions:
+	EOF
+	test_cmp expect actual &&
+	: >four &&
+	git update-index --add four &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	$BASE
+	100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0	four
+	replacements:
+	deletions:
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'check behavior with splitIndex.maxPercentChange unset' '
+	git config --unset splitIndex.maxPercentChange &&
+	: >five &&
+	git update-index --add five &&
+	BASE=$(test-dump-split-index .git/index | grep "^base") &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	$BASE
+	replacements:
+	deletions:
+	EOF
+	test_cmp expect actual &&
+	: >six &&
+	git update-index --add six &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	$BASE
+	100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0	six
+	replacements:
+	deletions:
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'check splitIndex.maxPercentChange set to 0' '
+	git config splitIndex.maxPercentChange 0 &&
+	: >seven &&
+	git update-index --add seven &&
+	BASE=$(test-dump-split-index .git/index | grep "^base") &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	$BASE
+	replacements:
+	deletions:
+	EOF
+	test_cmp expect actual &&
+	: >eight &&
+	git update-index --add eight &&
+	BASE=$(test-dump-split-index .git/index | grep "^base") &&
+	test-dump-split-index .git/index | sed "/^own/d" >actual &&
+	cat >expect <<-EOF &&
+	$BASE
+	replacements:
+	deletions:
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'shared index files expire after 2 weeks by default' '
+	: >ten &&
+	git update-index --add ten &&
+	test $(ls .git/sharedindex.* | wc -l) -gt 2 &&
+	just_under_2_weeks_ago=$((5-14*86400)) &&
+	test-chmtime =$just_under_2_weeks_ago .git/sharedindex.* &&
+	: >eleven &&
+	git update-index --add eleven &&
+	test $(ls .git/sharedindex.* | wc -l) -gt 2 &&
+	just_over_2_weeks_ago=$((-1-14*86400)) &&
+	test-chmtime =$just_over_2_weeks_ago .git/sharedindex.* &&
+	: >twelve &&
+	git update-index --add twelve &&
+	test $(ls .git/sharedindex.* | wc -l) -le 2
+'
+
+test_expect_success 'check splitIndex.sharedIndexExpire set to 16 days' '
+	git config splitIndex.sharedIndexExpire "16.days.ago" &&
+	test-chmtime =$just_over_2_weeks_ago .git/sharedindex.* &&
+	: >thirteen &&
+	git update-index --add thirteen &&
+	test $(ls .git/sharedindex.* | wc -l) -gt 2 &&
+	just_over_16_days_ago=$((-1-16*86400)) &&
+	test-chmtime =$just_over_16_days_ago .git/sharedindex.* &&
+	: >fourteen &&
+	git update-index --add fourteen &&
+	test $(ls .git/sharedindex.* | wc -l) -le 2
+'
+
+test_expect_success 'check splitIndex.sharedIndexExpire set to "never" and "now"' '
+	git config splitIndex.sharedIndexExpire never &&
+	just_10_years_ago=$((-365*10*86400)) &&
+	test-chmtime =$just_10_years_ago .git/sharedindex.* &&
+	: >fifteen &&
+	git update-index --add fifteen &&
+	test $(ls .git/sharedindex.* | wc -l) -gt 2 &&
+	git config splitIndex.sharedIndexExpire now &&
+	just_1_second_ago=-1 &&
+	test-chmtime =$just_1_second_ago .git/sharedindex.* &&
+	: >sixteen &&
+	git update-index --add sixteen &&
+	test $(ls .git/sharedindex.* | wc -l) -le 2
+'
+
 test_done
diff --git a/t/t2027-worktree-list.sh b/t/t2027-worktree-list.sh
index 465eeea..848da5f 100755
--- a/t/t2027-worktree-list.sh
+++ b/t/t2027-worktree-list.sh
@@ -14,10 +14,18 @@
 	test_cmp expected actual &&
 	mkdir sub &&
 	git -C sub rev-parse --git-common-dir >actual2 &&
-	echo sub/.git >expected2 &&
+	echo ../.git >expected2 &&
 	test_cmp expected2 actual2
 '
 
+test_expect_success 'rev-parse --git-path objects linked worktree' '
+	echo "$(git rev-parse --show-toplevel)/.git/objects" >expect &&
+	test_when_finished "rm -rf linked-tree && git worktree prune" &&
+	git worktree add --detach linked-tree master &&
+	git -C linked-tree rev-parse --git-path objects >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success '"list" all worktrees from main' '
 	echo "$(git rev-parse --show-toplevel) $(git rev-parse --short HEAD) [$(git symbolic-ref --short HEAD)]" >expect &&
 	test_when_finished "rm -rf here && git worktree prune" &&
diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index 8a833f3..9f353c0 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -139,6 +139,12 @@
 	test $(git rev-parse --abbrev-ref HEAD) = bam
 '
 
+test_expect_success 'git branch -M baz bam should add entries to .git/logs/HEAD' '
+	msg="Branch: renamed refs/heads/baz to refs/heads/bam" &&
+	grep " 0\{40\}.*$msg$" .git/logs/HEAD &&
+	grep "^0\{40\}.*$msg$" .git/logs/HEAD
+'
+
 test_expect_success 'git branch -M baz bam should succeed when baz is checked out as linked working tree' '
 	git checkout master &&
 	git worktree add -b baz bazdir &&
@@ -207,6 +213,31 @@
 	test_path_is_missing .git/refs/heads/t
 '
 
+test_expect_success 'git branch --list -v with --abbrev' '
+	test_when_finished "git branch -D t" &&
+	git branch t &&
+	git branch -v --list t >actual.default &&
+	git branch -v --list --abbrev t >actual.abbrev &&
+	test_cmp actual.default actual.abbrev &&
+
+	git branch -v --list --no-abbrev t >actual.noabbrev &&
+	git branch -v --list --abbrev=0 t >actual.0abbrev &&
+	test_cmp actual.noabbrev actual.0abbrev &&
+
+	git branch -v --list --abbrev=36 t >actual.36abbrev &&
+	# how many hexdigits are used?
+	read name objdefault rest <actual.abbrev &&
+	read name obj36 rest <actual.36abbrev &&
+	objfull=$(git rev-parse --verify t) &&
+
+	# are we really getting abbreviations?
+	test "$obj36" != "$objdefault" &&
+	expr "$obj36" : "$objdefault" >/dev/null &&
+	test "$objfull" != "$obj36" &&
+	expr "$objfull" : "$obj36" >/dev/null
+
+'
+
 test_expect_success 'git branch --column' '
 	COLUMNS=81 git branch --column=column >actual &&
 	cat >expected <<\EOF &&
diff --git a/t/t3203-branch-output.sh b/t/t3203-branch-output.sh
index 52283df..5778c0a 100755
--- a/t/t3203-branch-output.sh
+++ b/t/t3203-branch-output.sh
@@ -194,7 +194,7 @@
 	git symbolic-ref refs/heads/ref-to-remote refs/remotes/origin/branch-one &&
 	cat >expect <<-\EOF &&
 	  ref-to-branch -> branch-one
-	  ref-to-remote -> refs/remotes/origin/branch-one
+	  ref-to-remote -> origin/branch-one
 	EOF
 	git branch >actual.raw &&
 	grep ref-to <actual.raw >actual &&
@@ -225,4 +225,18 @@
 	)
 '
 
+test_expect_success 'git branch --format option' '
+	cat >expect <<-\EOF &&
+	Refname is (HEAD detached from fromtag)
+	Refname is refs/heads/ambiguous
+	Refname is refs/heads/branch-one
+	Refname is refs/heads/branch-two
+	Refname is refs/heads/master
+	Refname is refs/heads/ref-to-branch
+	Refname is refs/heads/ref-to-remote
+	EOF
+	git branch --format="Refname is %(refname)" >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t3204-branch-name-interpretation.sh b/t/t3204-branch-name-interpretation.sh
new file mode 100755
index 0000000..698d9cc
--- /dev/null
+++ b/t/t3204-branch-name-interpretation.sh
@@ -0,0 +1,133 @@
+#!/bin/sh
+
+test_description='interpreting exotic branch name arguments
+
+Branch name arguments are usually names which are taken to be inside of
+refs/heads/, but we interpret some magic syntax like @{-1}, @{upstream}, etc.
+This script aims to check the behavior of those corner cases.
+'
+. ./test-lib.sh
+
+expect_branch() {
+	git log -1 --format=%s "$1" >actual &&
+	echo "$2" >expect &&
+	test_cmp expect actual
+}
+
+expect_deleted() {
+	test_must_fail git rev-parse --verify "$1"
+}
+
+test_expect_success 'set up repo' '
+	test_commit one &&
+	test_commit two &&
+	git remote add origin foo.git
+'
+
+test_expect_success 'update branch via @{-1}' '
+	git branch previous one &&
+
+	git checkout previous &&
+	git checkout master &&
+
+	git branch -f @{-1} two &&
+	expect_branch previous two
+'
+
+test_expect_success 'update branch via local @{upstream}' '
+	git branch local one &&
+	git branch --set-upstream-to=local &&
+
+	git branch -f @{upstream} two &&
+	expect_branch local two
+'
+
+test_expect_success 'disallow updating branch via remote @{upstream}' '
+	git update-ref refs/remotes/origin/remote one &&
+	git branch --set-upstream-to=origin/remote &&
+
+	test_must_fail git branch -f @{upstream} two
+'
+
+test_expect_success 'create branch with pseudo-qualified name' '
+	git branch refs/heads/qualified two &&
+	expect_branch refs/heads/refs/heads/qualified two
+'
+
+test_expect_success 'delete branch via @{-1}' '
+	git branch previous-del &&
+
+	git checkout previous-del &&
+	git checkout master &&
+
+	git branch -D @{-1} &&
+	expect_deleted previous-del
+'
+
+test_expect_success 'delete branch via local @{upstream}' '
+	git branch local-del &&
+	git branch --set-upstream-to=local-del &&
+
+	git branch -D @{upstream} &&
+	expect_deleted local-del
+'
+
+test_expect_success 'delete branch via remote @{upstream}' '
+	git update-ref refs/remotes/origin/remote-del two &&
+	git branch --set-upstream-to=origin/remote-del &&
+
+	git branch -r -D @{upstream} &&
+	expect_deleted origin/remote-del
+'
+
+# Note that we create two oddly named local branches here. We want to make
+# sure that we do not accidentally delete either of them, even if
+# shorten_unambiguous_ref() tweaks the name to avoid ambiguity.
+test_expect_success 'delete @{upstream} expansion matches -r option' '
+	git update-ref refs/remotes/origin/remote-del two &&
+	git branch --set-upstream-to=origin/remote-del &&
+	git update-ref refs/heads/origin/remote-del two &&
+	git update-ref refs/heads/remotes/origin/remote-del two &&
+
+	test_must_fail git branch -D @{upstream} &&
+	expect_branch refs/heads/origin/remote-del two &&
+	expect_branch refs/heads/remotes/origin/remote-del two
+'
+
+test_expect_success 'disallow deleting remote branch via @{-1}' '
+	git update-ref refs/remotes/origin/previous one &&
+
+	git checkout -b origin/previous two &&
+	git checkout master &&
+
+	test_must_fail git branch -r -D @{-1} &&
+	expect_branch refs/remotes/origin/previous one &&
+	expect_branch refs/heads/origin/previous two
+'
+
+# The thing we are testing here is that "@" is the real branch refs/heads/@,
+# and not refs/heads/HEAD. These tests should not imply that refs/heads/@ is a
+# sane thing, but it _is_ technically allowed for now. If we disallow it, these
+# can be switched to test_must_fail.
+test_expect_success 'create branch named "@"' '
+	git branch -f @ one &&
+	expect_branch refs/heads/@ one
+'
+
+test_expect_success 'delete branch named "@"' '
+	git update-ref refs/heads/@ two &&
+	git branch -D @ &&
+	expect_deleted refs/heads/@
+'
+
+test_expect_success 'checkout does not treat remote @{upstream} as a branch' '
+	git update-ref refs/remotes/origin/checkout one &&
+	git branch --set-upstream-to=origin/checkout &&
+	git update-ref refs/heads/origin/checkout two &&
+	git update-ref refs/heads/remotes/origin/checkout two &&
+
+	git checkout @{upstream} &&
+	expect_branch HEAD one
+'
+
+test_done
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index e2f18d1..33d392b 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -556,7 +556,7 @@
 	echo "edited again" > file7 &&
 	git add file7 &&
 	test_must_fail git rebase --continue 2>error &&
-	test_i18ngrep "You have staged changes in your working tree." error
+	test_i18ngrep "you have staged changes in your working tree" error
 '
 
 test_expect_success 'rebase a detached HEAD' '
diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
index 5ffe78e..f9528fa 100755
--- a/t/t3701-add-interactive.sh
+++ b/t/t3701-add-interactive.sh
@@ -394,4 +394,65 @@
 	grep "$(printf "\\033")" output
 '
 
+test_expect_success 'patch-mode via -i prompts for files' '
+	git reset --hard &&
+
+	echo one >file &&
+	echo two >test &&
+	git add -i <<-\EOF &&
+	patch
+	test
+
+	y
+	quit
+	EOF
+
+	echo test >expect &&
+	git diff --cached --name-only >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'add -p handles globs' '
+	git reset --hard &&
+
+	mkdir -p subdir &&
+	echo base >one.c &&
+	echo base >subdir/two.c &&
+	git add "*.c" &&
+	git commit -m base &&
+
+	echo change >one.c &&
+	echo change >subdir/two.c &&
+	git add -p "*.c" <<-\EOF &&
+	y
+	y
+	EOF
+
+	cat >expect <<-\EOF &&
+	one.c
+	subdir/two.c
+	EOF
+	git diff --cached --name-only >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'add -p does not expand argument lists' '
+	git reset --hard &&
+
+	echo content >not-changed &&
+	git add not-changed &&
+	git commit -m "add not-changed file" &&
+
+	echo change >file &&
+	GIT_TRACE=$(pwd)/trace.out git add -p . <<-\EOF &&
+	y
+	EOF
+
+	# we know that "file" must be mentioned since we actually
+	# update it, but we want to be sure that our "." pathspec
+	# was not expanded into the argument list of any command.
+	# So look only for "not-changed".
+	! grep not-changed trace.out
+'
+
 test_done
diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh
index 2de3e18..89877e4 100755
--- a/t/t3903-stash.sh
+++ b/t/t3903-stash.sh
@@ -274,9 +274,7 @@
 	git add file2 &&
 	test_must_fail git stash --invalid-option &&
 	test_must_fail git stash save --invalid-option &&
-	test bar5,bar6 = $(cat file),$(cat file2) &&
-	git stash -- -message-starting-with-dash &&
-	test bar,bar2 = $(cat file),$(cat file2)
+	test bar5,bar6 = $(cat file),$(cat file2)
 '
 
 test_expect_success 'stash an added file' '
@@ -775,4 +773,138 @@
 	test_path_is_missing file
 '
 
+test_expect_success 'push -m shows right message' '
+	>foo &&
+	git add foo &&
+	git stash push -m "test message" &&
+	echo "stash@{0}: On master: test message" >expect &&
+	git stash list -1 >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'create stores correct message' '
+	>foo &&
+	git add foo &&
+	STASH_ID=$(git stash create "create test message") &&
+	echo "On master: create test message" >expect &&
+	git show --pretty=%s -s ${STASH_ID} >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'create with multiple arguments for the message' '
+	>foo &&
+	git add foo &&
+	STASH_ID=$(git stash create test untracked) &&
+	echo "On master: test untracked" >expect &&
+	git show --pretty=%s -s ${STASH_ID} >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'stash -- <pathspec> stashes and restores the file' '
+	>foo &&
+	>bar &&
+	git add foo bar &&
+	git stash push -- foo &&
+	test_path_is_file bar &&
+	test_path_is_missing foo &&
+	git stash pop &&
+	test_path_is_file foo &&
+	test_path_is_file bar
+'
+
+test_expect_success 'stash with multiple pathspec arguments' '
+	>foo &&
+	>bar &&
+	>extra &&
+	git add foo bar extra &&
+	git stash push -- foo bar &&
+	test_path_is_missing bar &&
+	test_path_is_missing foo &&
+	test_path_is_file extra &&
+	git stash pop &&
+	test_path_is_file foo &&
+	test_path_is_file bar &&
+	test_path_is_file extra
+'
+
+test_expect_success 'stash with file including $IFS character' '
+	>"foo bar" &&
+	>foo &&
+	>bar &&
+	git add foo* &&
+	git stash push -- "foo b*" &&
+	test_path_is_missing "foo bar" &&
+	test_path_is_file foo &&
+	test_path_is_file bar &&
+	git stash pop &&
+	test_path_is_file "foo bar" &&
+	test_path_is_file foo &&
+	test_path_is_file bar
+'
+
+test_expect_success 'stash with pathspec matching multiple paths' '
+       echo original >file &&
+       echo original >other-file &&
+       git commit -m "two" file other-file &&
+       echo modified >file &&
+       echo modified >other-file &&
+       git stash push -- "*file" &&
+       echo original >expect &&
+       test_cmp expect file &&
+       test_cmp expect other-file &&
+       git stash pop &&
+       echo modified >expect &&
+       test_cmp expect file &&
+       test_cmp expect other-file
+'
+
+test_expect_success 'stash push -p with pathspec shows no changes only once' '
+	>foo &&
+	git add foo &&
+	git commit -m "tmp" &&
+	git stash push -p foo >actual &&
+	echo "No local changes to save" >expect &&
+	git reset --hard HEAD~ &&
+	test_cmp expect actual
+'
+
+test_expect_success 'stash push with pathspec shows no changes when there are none' '
+	>foo &&
+	git add foo &&
+	git commit -m "tmp" &&
+	git stash push foo >actual &&
+	echo "No local changes to save" >expect &&
+	git reset --hard HEAD~ &&
+	test_cmp expect actual
+'
+
+test_expect_success 'stash push with pathspec not in the repository errors out' '
+	>untracked &&
+	test_must_fail git stash push untracked &&
+	test_path_is_file untracked
+'
+
+test_expect_success 'untracked files are left in place when -u is not given' '
+	>file &&
+	git add file &&
+	>untracked &&
+	git stash push file &&
+	test_path_is_file untracked
+'
+
+test_expect_success 'stash without verb with pathspec' '
+	>"foo bar" &&
+	>foo &&
+	>bar &&
+	git add foo* &&
+	git stash -- "foo b*" &&
+	test_path_is_missing "foo bar" &&
+	test_path_is_file foo &&
+	test_path_is_file bar &&
+	git stash pop &&
+	test_path_is_file "foo bar" &&
+	test_path_is_file foo &&
+	test_path_is_file bar
+'
+
 test_done
diff --git a/t/t3905-stash-include-untracked.sh b/t/t3905-stash-include-untracked.sh
index f372fc8..193adc7 100755
--- a/t/t3905-stash-include-untracked.sh
+++ b/t/t3905-stash-include-untracked.sh
@@ -185,4 +185,30 @@
 	test -s .gitignore
 '
 
+test_expect_success 'stash push --include-untracked with pathspec' '
+	>foo &&
+	>bar &&
+	git stash push --include-untracked -- foo &&
+	test_path_is_file bar &&
+	test_path_is_missing foo &&
+	git stash pop &&
+	test_path_is_file bar &&
+	test_path_is_file foo
+'
+
+test_expect_success 'stash push with $IFS character' '
+	>"foo bar" &&
+	>foo &&
+	>bar &&
+	git add foo* &&
+	git stash push --include-untracked -- "foo b*" &&
+	test_path_is_missing "foo bar" &&
+	test_path_is_file foo &&
+	test_path_is_file bar &&
+	git stash pop &&
+	test_path_is_file "foo bar" &&
+	test_path_is_file foo &&
+	test_path_is_file bar
+'
+
 test_done
diff --git a/t/t4035-diff-quiet.sh b/t/t4035-diff-quiet.sh
index 461f4bb..2f1737f 100755
--- a/t/t4035-diff-quiet.sh
+++ b/t/t4035-diff-quiet.sh
@@ -152,4 +152,13 @@
 	test_expect_code 1 git diff --quiet
 '
 
+test_expect_success 'git diff --quiet on a path that need conversion' '
+	echo "crlf.txt text=auto" >.gitattributes &&
+	printf "Hello\r\nWorld\r\n" >crlf.txt &&
+	git add .gitattributes crlf.txt &&
+
+	printf "Hello\r\nWorld\n" >crlf.txt &&
+	git diff --quiet crlf.txt
+'
+
 test_done
diff --git a/t/t4211-line-log.sh b/t/t4211-line-log.sh
index 9d87777..d0377fa 100755
--- a/t/t4211-line-log.sh
+++ b/t/t4211-line-log.sh
@@ -106,4 +106,14 @@
 	test_line_count = 70 log
 '
 
+test_expect_success 'range_set_union' '
+	test_seq 500 > c.c &&
+	git add c.c &&
+	git commit -m "many lines" &&
+	test_seq 1000 > c.c &&
+	git add c.c &&
+	git commit -m "modify many lines" &&
+	git log $(for x in $(test_seq 200); do echo -L $((2*x)),+1:c.c; done)
+'
+
 test_done
diff --git a/t/t5316-pack-delta-depth.sh b/t/t5316-pack-delta-depth.sh
new file mode 100755
index 0000000..37143ea
--- /dev/null
+++ b/t/t5316-pack-delta-depth.sh
@@ -0,0 +1,93 @@
+#!/bin/sh
+
+test_description='pack-objects breaks long cross-pack delta chains'
+. ./test-lib.sh
+
+# This mirrors a repeated push setup:
+#
+# 1. A client repeatedly modifies some files, makes a
+#      commit, and pushes the result. It does this N times
+#      before we get around to repacking.
+#
+# 2. Each push generates a thin pack with the new version of
+#    various objects. Let's consider some file in the root tree
+#    which is updated in each commit.
+#
+#    When generating push number X, we feed commit X-1 (and
+#    thus blob X-1) as a preferred base. The resulting pack has
+#    blob X as a thin delta against blob X-1.
+#
+#    On the receiving end, "index-pack --fix-thin" will
+#    complete the pack with a base copy of blob X-1.
+#
+# 3. In older versions of git, if we used the delta from
+#    pack X, then we'd always find blob X-1 as a base in the
+#    same pack (and generate a fresh delta).
+#
+#    But with the pack mru, we jump from delta to delta
+#    following the traversal order:
+#
+#      a. We grab blob X from pack X as a delta, putting it at
+#         the tip of our mru list.
+#
+#      b. Eventually we move onto commit X-1. We need other
+#         objects which are only in pack X-1 (in the test code
+#         below, it's the containing tree). That puts pack X-1
+#         at the tip of our mru list.
+#
+#      c. Eventually we look for blob X-1, and we find the
+#         version in pack X-1 (because it's the mru tip).
+#
+# Now we have blob X as a delta against X-1, which is a delta
+# against X-2, and so forth.
+#
+# In the real world, these small pushes would get exploded by
+# unpack-objects rather than "index-pack --fix-thin", but the
+# same principle applies to larger pushes (they only need one
+# repeatedly-modified file to generate the delta chain).
+
+test_expect_success 'create series of packs' '
+	test-genrandom foo 4096 >content &&
+	prev= &&
+	for i in $(test_seq 1 10)
+	do
+		cat content >file &&
+		echo $i >>file &&
+		git add file &&
+		git commit -m $i &&
+		cur=$(git rev-parse HEAD^{tree}) &&
+		{
+			test -n "$prev" && echo "-$prev"
+			echo $cur
+			echo "$(git rev-parse :file) file"
+		} | git pack-objects --stdout >tmp &&
+		git index-pack --stdin --fix-thin <tmp || return 1
+		prev=$cur
+	done
+'
+
+max_chain() {
+	git index-pack --verify-stat-only "$1" >output &&
+	perl -lne '
+	  /chain length = (\d+)/ and $len = $1;
+	  END { print $len }
+	' output
+}
+
+# Note that this whole setup is pretty reliant on the current
+# packing heuristics. We double-check that our test case
+# actually produces a long chain. If it doesn't, it should be
+# adjusted (or scrapped if the heuristics have become too unreliable)
+test_expect_success 'packing produces a long delta' '
+	# Use --window=0 to make sure we are seeing reused deltas,
+	# not computing a new long chain.
+	pack=$(git pack-objects --all --window=0 </dev/null pack) &&
+	test 9 = "$(max_chain pack-$pack.pack)"
+'
+
+test_expect_success '--depth limits depth' '
+	pack=$(git pack-objects --all --depth=5 </dev/null pack) &&
+	test 5 = "$(max_chain pack-$pack.pack)"
+'
+
+test_done
diff --git a/t/t5400-send-pack.sh b/t/t5400-send-pack.sh
index 305ca7a..3331e0f 100755
--- a/t/t5400-send-pack.sh
+++ b/t/t5400-send-pack.sh
@@ -255,4 +255,42 @@
 	)
 '
 
+extract_ref_advertisement () {
+	perl -lne '
+		# \\ is there to skip capabilities after \0
+		/push< ([^\\]+)/ or next;
+		exit 0 if $1 eq "0000";
+		print $1;
+	'
+}
+
+test_expect_success 'receive-pack de-dupes .have lines' '
+	git init shared &&
+	git -C shared commit --allow-empty -m both &&
+	git clone -s shared fork &&
+	(
+		cd shared &&
+		git checkout -b only-shared &&
+		git commit --allow-empty -m only-shared &&
+		git update-ref refs/heads/foo HEAD
+	) &&
+
+	# Notable things in this expectation:
+	#  - local refs are not de-duped
+	#  - .have does not duplicate locals
+	#  - .have does not duplicate itself
+	local=$(git -C fork rev-parse HEAD) &&
+	shared=$(git -C shared rev-parse only-shared) &&
+	cat >expect <<-EOF &&
+	$local refs/heads/master
+	$local refs/remotes/origin/HEAD
+	$local refs/remotes/origin/master
+	$shared .have
+	EOF
+
+	GIT_TRACE_PACKET=$(pwd)/trace git push fork HEAD:foo &&
+	extract_ref_advertisement <trace >refs &&
+	test_cmp expect refs
+'
+
 test_done
diff --git a/t/t5500-fetch-pack.sh b/t/t5500-fetch-pack.sh
index 505e1b4..b5865b3 100755
--- a/t/t5500-fetch-pack.sh
+++ b/t/t5500-fetch-pack.sh
@@ -484,7 +484,7 @@
 		cd client &&
 		test_must_fail git fetch-pack --no-progress .. refs/heads/xyzzy
 	) >/dev/null 2>error-m &&
-	test_cmp expect-error error-m
+	test_i18ncmp expect-error error-m
 '
 
 test_expect_success 'test missing ref after existing' '
@@ -492,7 +492,7 @@
 		cd client &&
 		test_must_fail git fetch-pack --no-progress .. refs/heads/A refs/heads/xyzzy
 	) >/dev/null 2>error-em &&
-	test_cmp expect-error error-em
+	test_i18ncmp expect-error error-em
 '
 
 test_expect_success 'test missing ref before existing' '
@@ -500,7 +500,7 @@
 		cd client &&
 		test_must_fail git fetch-pack --no-progress .. refs/heads/xyzzy refs/heads/A
 	) >/dev/null 2>error-me &&
-	test_cmp expect-error error-me
+	test_i18ncmp expect-error error-me
 '
 
 test_expect_success 'test --all, --depth, and explicit head' '
diff --git a/t/t5505-remote.sh b/t/t5505-remote.sh
index ba46e86..a6c0178 100755
--- a/t/t5505-remote.sh
+++ b/t/t5505-remote.sh
@@ -153,6 +153,25 @@
 	)
 '
 
+test_expect_success 'remove remote with a branch without configured merge' '
+	test_when_finished "(
+		git -C test checkout master;
+		git -C test branch -D two;
+		git -C test config --remove-section remote.two;
+		git -C test config --remove-section branch.second;
+		true
+	)" &&
+	(
+		cd test &&
+		git remote add two ../two &&
+		git fetch two &&
+		git checkout -b second two/master^0 &&
+		git config branch.second.remote two &&
+		git checkout master &&
+		git remote rm two
+	)
+'
+
 test_expect_success 'rename errors out early when deleting non-existent branch' '
 	(
 		cd test &&
@@ -725,7 +744,7 @@
 	(
 		cd four &&
 		git remote rename origin upstream &&
-		rmdir .git/refs/remotes/origin &&
+		test -z "$(git for-each-ref refs/remotes/origin)" &&
 		test "$(git symbolic-ref refs/remotes/upstream/HEAD)" = "refs/remotes/upstream/master" &&
 		test "$(git rev-parse upstream/master)" = "$(git rev-parse master)" &&
 		test "$(git config remote.upstream.fetch)" = "+refs/heads/*:refs/remotes/upstream/*" &&
diff --git a/t/t5512-ls-remote.sh b/t/t5512-ls-remote.sh
index 55fc83f..94fc9be 100755
--- a/t/t5512-ls-remote.sh
+++ b/t/t5512-ls-remote.sh
@@ -248,4 +248,13 @@
 	test_expect_code 2 git ls-remote --exit-code git://localhost:$JGIT_DAEMON_PORT/empty.git
 '
 
+test_expect_success 'ls-remote works outside repository' '
+	# It is important for this repo to be inside the nongit
+	# area, as we want a repo name that does not include
+	# slashes (because those inhibit some of our configuration
+	# lookups).
+	nongit git init --bare dst.git &&
+	nongit git ls-remote dst.git
+'
+
 test_done
diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index 0fc5a7c..177897e 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -1098,7 +1098,8 @@
 		test_must_fail git cat-file -t $the_commit &&
 
 		# fetching the hidden object should fail by default
-		test_must_fail git fetch -v ../testrepo $the_commit:refs/heads/copy &&
+		test_must_fail git fetch -v ../testrepo $the_commit:refs/heads/copy 2>err &&
+		test_i18ngrep "Server does not allow request for unadvertised object" err &&
 		test_must_fail git rev-parse --verify refs/heads/copy &&
 
 		# the server side can allow it to succeed
diff --git a/t/t5550-http-fetch-dumb.sh b/t/t5550-http-fetch-dumb.sh
index aeb3a63..87308cd 100755
--- a/t/t5550-http-fetch-dumb.sh
+++ b/t/t5550-http-fetch-dumb.sh
@@ -34,6 +34,15 @@
 	test_cmp file clone/file
 '
 
+test_expect_success 'list refs from outside any repository' '
+	cat >expect <<-EOF &&
+	$(git rev-parse master)	HEAD
+	$(git rev-parse master)	refs/heads/master
+	EOF
+	nongit git ls-remote "$HTTPD_URL/dumb/repo.git" >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'create password-protected repository' '
 	mkdir -p "$HTTPD_DOCUMENT_ROOT_PATH/auth/dumb/" &&
 	cp -Rf "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" \
@@ -378,5 +387,14 @@
 		clone $HTTPD_URL/dumb/evil.git evil-user
 '
 
+test_expect_success 'can redirect through non-"info/refs?service=git-upload-pack" URL' '
+	git clone "$HTTPD_URL/redir-to/dumb/repo.git"
+'
+
+test_expect_success 'print HTTP error when any intermediate redirect throws error' '
+	test_must_fail git clone "$HTTPD_URL/redir-to/502" 2> stderr &&
+	test_i18ngrep "unable to access.*/redir-to/502" stderr
+'
+
 stop_httpd
 test_done
diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index 4241ea5..b52b8ac 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -386,6 +386,47 @@
 	expect_ssh "-batch -P 123" myhost src
 '
 
+test_expect_success 'double quoted plink.exe in GIT_SSH_COMMAND' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink.exe" &&
+	GIT_SSH_COMMAND="\"$TRASH_DIRECTORY/plink.exe\" -v" \
+		git clone "[myhost:123]:src" ssh-bracket-clone-plink-3 &&
+	expect_ssh "-v -P 123" myhost src
+'
+
+SQ="'"
+test_expect_success 'single quoted plink.exe in GIT_SSH_COMMAND' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink.exe" &&
+	GIT_SSH_COMMAND="$SQ$TRASH_DIRECTORY/plink.exe$SQ -v" \
+		git clone "[myhost:123]:src" ssh-bracket-clone-plink-4 &&
+	expect_ssh "-v -P 123" myhost src
+'
+
+test_expect_success 'GIT_SSH_VARIANT overrides plink detection' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink" &&
+	GIT_SSH_VARIANT=ssh \
+	git clone "[myhost:123]:src" ssh-bracket-clone-variant-1 &&
+	expect_ssh "-p 123" myhost src
+'
+
+test_expect_success 'ssh.variant overrides plink detection' '
+	copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink" &&
+	git -c ssh.variant=ssh \
+		clone "[myhost:123]:src" ssh-bracket-clone-variant-2 &&
+	expect_ssh "-p 123" myhost src
+'
+
+test_expect_success 'GIT_SSH_VARIANT overrides plink detection to plink' '
+	GIT_SSH_VARIANT=plink \
+	git clone "[myhost:123]:src" ssh-bracket-clone-variant-3 &&
+	expect_ssh "-P 123" myhost src
+'
+
+test_expect_success 'GIT_SSH_VARIANT overrides plink to tortoiseplink' '
+	GIT_SSH_VARIANT=tortoiseplink \
+	git clone "[myhost:123]:src" ssh-bracket-clone-variant-4 &&
+	expect_ssh "-batch -P 123" myhost src
+'
+
 # Reset the GIT_SSH environment variable for clone tests.
 setup_ssh_wrapper
 
diff --git a/t/t6007-rev-list-cherry-pick-file.sh b/t/t6007-rev-list-cherry-pick-file.sh
index 1408b60..2959745 100755
--- a/t/t6007-rev-list-cherry-pick-file.sh
+++ b/t/t6007-rev-list-cherry-pick-file.sh
@@ -99,6 +99,44 @@
 	test_cmp actual.named expect
 '
 
+test_expect_success 'name-rev multiple --refs combine inclusive' '
+	git rev-list --left-right --cherry-pick F...E -- bar >actual &&
+	git name-rev --stdin --name-only --refs="*tags/F" --refs="*tags/E" \
+		<actual >actual.named &&
+	test_cmp actual.named expect
+'
+
+cat >expect <<EOF
+<tags/F
+EOF
+
+test_expect_success 'name-rev --refs excludes non-matched patterns' '
+	git rev-list --left-right --right-only --cherry-pick F...E -- bar >>expect &&
+	git rev-list --left-right --cherry-pick F...E -- bar >actual &&
+	git name-rev --stdin --name-only --refs="*tags/F" \
+		<actual >actual.named &&
+	test_cmp actual.named expect
+'
+
+cat >expect <<EOF
+<tags/F
+EOF
+
+test_expect_success 'name-rev --exclude excludes matched patterns' '
+	git rev-list --left-right --right-only --cherry-pick F...E -- bar >>expect &&
+	git rev-list --left-right --cherry-pick F...E -- bar >actual &&
+	git name-rev --stdin --name-only --refs="*tags/*" --exclude="*E" \
+		<actual >actual.named &&
+	test_cmp actual.named expect
+'
+
+test_expect_success 'name-rev --no-refs clears the refs list' '
+	git rev-list --left-right --cherry-pick F...E -- bar >expect &&
+	git name-rev --stdin --name-only --refs="*tags/F" --refs="*tags/E" --no-refs --refs="*tags/G" \
+		<expect >actual &&
+	test_cmp actual expect
+'
+
 cat >expect <<EOF
 +tags/F
 =tags/D
diff --git a/t/t6040-tracking-info.sh b/t/t6040-tracking-info.sh
index 3d5c238..97a0765 100755
--- a/t/t6040-tracking-info.sh
+++ b/t/t6040-tracking-info.sh
@@ -44,7 +44,7 @@
 b2 [ahead 1, behind 1] d
 b3 [behind 1] b
 b4 [ahead 2] f
-b5 g
+b5 [gone] g
 b6 c
 EOF
 
diff --git a/t/t6045-merge-rename-delete.sh b/t/t6045-merge-rename-delete.sh
new file mode 100755
index 0000000..5d33577
--- /dev/null
+++ b/t/t6045-merge-rename-delete.sh
@@ -0,0 +1,23 @@
+#!/bin/sh
+
+test_description='Merge-recursive rename/delete conflict message'
+. ./test-lib.sh
+
+test_expect_success 'rename/delete' '
+	echo foo >A &&
+	git add A &&
+	git commit -m "initial" &&
+
+	git checkout -b rename &&
+	git mv A B &&
+	git commit -m "rename" &&
+
+	git checkout master &&
+	git rm A &&
+	git commit -m "delete" &&
+
+	test_must_fail git merge --strategy=recursive rename >output &&
+	test_i18ngrep "CONFLICT (rename/delete): A deleted in HEAD and renamed to B in rename. Version rename of B left in tree." output
+'
+
+test_done
diff --git a/t/t6120-describe.sh b/t/t6120-describe.sh
index 85f2694..167491f 100755
--- a/t/t6120-describe.sh
+++ b/t/t6120-describe.sh
@@ -182,6 +182,10 @@
 
 check_describe "test2-lightweight-*" --long --tags --match="test2-*" HEAD^
 
+check_describe "test1-lightweight-*" --long --tags --match="test1-*" --match="test2-*" HEAD^
+
+check_describe "test2-lightweight-*" --long --tags --match="test1-*" --no-match --match="test2-*" HEAD^
+
 test_expect_success 'name-rev with exact tags' '
 	echo A >expect &&
 	tag_object=$(git rev-parse refs/tags/A) &&
@@ -206,4 +210,27 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'describe --contains and --match' '
+	echo "A^0" >expect &&
+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
+	test_must_fail git describe --contains --match="B" $tagged_commit &&
+	git describe --contains --match="B" --match="A" $tagged_commit >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'describe --exclude' '
+	echo "c~1" >expect &&
+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
+	test_must_fail git describe --contains --match="B" $tagged_commit &&
+	git describe --contains --match="?" --exclude="A" $tagged_commit >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'describe --contains and --no-match' '
+	echo "A^0" >expect &&
+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
+	git describe --contains --match="B" --no-match $tagged_commit >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t6132-pathspec-exclude.sh b/t/t6132-pathspec-exclude.sh
index d51595c..9dd5cde 100755
--- a/t/t6132-pathspec-exclude.sh
+++ b/t/t6132-pathspec-exclude.sh
@@ -25,8 +25,10 @@
 	test_cmp expect actual
 '
 
-test_expect_success 'exclude only should error out' '
-	test_must_fail git log --oneline --format=%s -- ":(exclude)sub"
+test_expect_success 'exclude only no longer errors out' '
+	git log --oneline --format=%s -- . ":(exclude)sub" >expect &&
+	git log --oneline --format=%s -- ":(exclude)sub" >actual &&
+	test_cmp expect actual
 '
 
 test_expect_success 't_e_i() exclude sub' '
diff --git a/t/t6135-pathspec-with-attrs.sh b/t/t6135-pathspec-with-attrs.sh
new file mode 100755
index 0000000..77b8cef
--- /dev/null
+++ b/t/t6135-pathspec-with-attrs.sh
@@ -0,0 +1,200 @@
+#!/bin/sh
+
+test_description='test labels in pathspecs'
+. ./test-lib.sh
+
+test_expect_success 'setup a tree' '
+	cat <<-\EOF >expect &&
+	fileA
+	fileAB
+	fileAC
+	fileB
+	fileBC
+	fileC
+	fileNoLabel
+	fileSetLabel
+	fileUnsetLabel
+	fileValue
+	fileWrongLabel
+	sub/fileA
+	sub/fileAB
+	sub/fileAC
+	sub/fileB
+	sub/fileBC
+	sub/fileC
+	sub/fileNoLabel
+	sub/fileSetLabel
+	sub/fileUnsetLabel
+	sub/fileValue
+	sub/fileWrongLabel
+	EOF
+	mkdir sub &&
+	while read path
+	do
+		: >$path &&
+		git add $path || return 1
+	done <expect &&
+	git commit -m "initial commit" &&
+	git ls-files >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'pathspec with no attr' '
+	test_must_fail git ls-files ":(attr:)"
+'
+
+test_expect_success 'pathspec with labels and non existent .gitattributes' '
+	git ls-files ":(attr:label)" >actual &&
+	test_must_be_empty actual
+'
+
+test_expect_success 'setup .gitattributes' '
+	cat <<-\EOF >.gitattributes &&
+	fileA labelA
+	fileB labelB
+	fileC labelC
+	fileAB labelA labelB
+	fileAC labelA labelC
+	fileBC labelB labelC
+	fileUnsetLabel -label
+	fileSetLabel label
+	fileValue label=foo
+	fileWrongLabel label☺
+	EOF
+	git add .gitattributes &&
+	git commit -m "add attributes"
+'
+
+test_expect_success 'check specific set attr' '
+	cat <<-\EOF >expect &&
+	fileSetLabel
+	sub/fileSetLabel
+	EOF
+	git ls-files ":(attr:label)" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'check specific unset attr' '
+	cat <<-\EOF >expect &&
+	fileUnsetLabel
+	sub/fileUnsetLabel
+	EOF
+	git ls-files ":(attr:-label)" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'check specific value attr' '
+	cat <<-\EOF >expect &&
+	fileValue
+	sub/fileValue
+	EOF
+	git ls-files ":(attr:label=foo)" >actual &&
+	test_cmp expect actual &&
+	git ls-files ":(attr:label=bar)" >actual &&
+	test_must_be_empty actual
+'
+
+test_expect_success 'check unspecified attr' '
+	cat <<-\EOF >expect &&
+	.gitattributes
+	fileA
+	fileAB
+	fileAC
+	fileB
+	fileBC
+	fileC
+	fileNoLabel
+	fileWrongLabel
+	sub/fileA
+	sub/fileAB
+	sub/fileAC
+	sub/fileB
+	sub/fileBC
+	sub/fileC
+	sub/fileNoLabel
+	sub/fileWrongLabel
+	EOF
+	git ls-files ":(attr:!label)" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'check multiple unspecified attr' '
+	cat <<-\EOF >expect &&
+	.gitattributes
+	fileC
+	fileNoLabel
+	fileWrongLabel
+	sub/fileC
+	sub/fileNoLabel
+	sub/fileWrongLabel
+	EOF
+	git ls-files ":(attr:!labelB !labelA !label)" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'check label with more labels but excluded path' '
+	cat <<-\EOF >expect &&
+	fileAB
+	fileB
+	fileBC
+	EOF
+	git ls-files ":(attr:labelB)" ":(exclude)sub/" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'check label excluding other labels' '
+	cat <<-\EOF >expect &&
+	fileAB
+	fileB
+	fileBC
+	sub/fileAB
+	sub/fileB
+	EOF
+	git ls-files ":(attr:labelB)" ":(exclude,attr:labelC)sub/" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'fail on multiple attr specifiers in one pathspec item' '
+	test_must_fail git ls-files . ":(attr:labelB,attr:labelC)" 2>actual &&
+	test_i18ngrep "Only one" actual
+'
+
+test_expect_success 'fail if attr magic is used places not implemented' '
+	# The main purpose of this test is to check that we actually fail
+	# when you attempt to use attr magic in commands that do not implement
+	# attr magic. This test does not advocate git-add to stay that way,
+	# though, but git-add is convenient as it has its own internal pathspec
+	# parsing.
+	test_must_fail git add ":(attr:labelB)" 2>actual &&
+	test_i18ngrep "unsupported magic" actual
+'
+
+test_expect_success 'abort on giving invalid label on the command line' '
+	test_must_fail git ls-files . ":(attr:☺)"
+'
+
+test_expect_success 'abort on asking for wrong magic' '
+	test_must_fail git ls-files . ":(attr:-label=foo)" &&
+	test_must_fail git ls-files . ":(attr:!label=foo)"
+'
+
+test_expect_success 'check attribute list' '
+	cat <<-EOF >>.gitattributes &&
+	* whitespace=indent,trail,space
+	EOF
+	git ls-files ":(attr:whitespace=indent\,trail\,space)" >actual &&
+	git ls-files >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'backslash cannot be the last character' '
+	test_must_fail git ls-files ":(attr:label=foo\\ labelA=bar)" 2>actual &&
+	test_i18ngrep "not allowed as last character in attr value" actual
+'
+
+test_expect_success 'backslash cannot be used as a value' '
+	test_must_fail git ls-files ":(attr:label=f\\\oo)" 2>actual &&
+	test_i18ngrep "for value matching" actual
+'
+
+test_done
diff --git a/t/t6300-for-each-ref.sh b/t/t6300-for-each-ref.sh
index aea1dfc..834a9ed 100755
--- a/t/t6300-for-each-ref.sh
+++ b/t/t6300-for-each-ref.sh
@@ -38,6 +38,7 @@
 	case "$1" in
 		head) ref=refs/heads/master ;;
 		 tag) ref=refs/tags/testtag ;;
+		 sym) ref=refs/heads/sym ;;
 		   *) ref=$1 ;;
 	esac
 	printf '%s\n' "$3" >expected
@@ -50,16 +51,40 @@
 
 test_atom head refname refs/heads/master
 test_atom head refname:short master
+test_atom head refname:lstrip=1 heads/master
+test_atom head refname:lstrip=2 master
+test_atom head refname:lstrip=-1 master
+test_atom head refname:lstrip=-2 heads/master
+test_atom head refname:rstrip=1 refs/heads
+test_atom head refname:rstrip=2 refs
+test_atom head refname:rstrip=-1 refs
+test_atom head refname:rstrip=-2 refs/heads
 test_atom head refname:strip=1 heads/master
 test_atom head refname:strip=2 master
+test_atom head refname:strip=-1 master
+test_atom head refname:strip=-2 heads/master
 test_atom head upstream refs/remotes/origin/master
 test_atom head upstream:short origin/master
+test_atom head upstream:lstrip=2 origin/master
+test_atom head upstream:lstrip=-2 origin/master
+test_atom head upstream:rstrip=2 refs/remotes
+test_atom head upstream:rstrip=-2 refs/remotes
+test_atom head upstream:strip=2 origin/master
+test_atom head upstream:strip=-2 origin/master
 test_atom head push refs/remotes/myfork/master
 test_atom head push:short myfork/master
+test_atom head push:lstrip=1 remotes/myfork/master
+test_atom head push:lstrip=-1 master
+test_atom head push:rstrip=1 refs/remotes/myfork
+test_atom head push:rstrip=-1 refs
+test_atom head push:strip=1 remotes/myfork/master
+test_atom head push:strip=-1 master
 test_atom head objecttype commit
 test_atom head objectsize 171
 test_atom head objectname $(git rev-parse refs/heads/master)
 test_atom head objectname:short $(git rev-parse --short refs/heads/master)
+test_atom head objectname:short=1 $(git rev-parse --short=1 refs/heads/master)
+test_atom head objectname:short=10 $(git rev-parse --short=10 refs/heads/master)
 test_atom head tree $(git rev-parse refs/heads/master^{tree})
 test_atom head parent ''
 test_atom head numparent 0
@@ -99,6 +124,8 @@
 test_atom tag objectsize 154
 test_atom tag objectname $(git rev-parse refs/tags/testtag)
 test_atom tag objectname:short $(git rev-parse --short refs/tags/testtag)
+test_atom head objectname:short=1 $(git rev-parse --short=1 refs/heads/master)
+test_atom head objectname:short=10 $(git rev-parse --short=10 refs/heads/master)
 test_atom tag tree ''
 test_atom tag parent ''
 test_atom tag numparent ''
@@ -134,16 +161,6 @@
 	test_must_fail git for-each-ref --format="%(INVALID)" refs/heads
 '
 
-test_expect_success 'arguments to :strip must be positive integers' '
-	test_must_fail git for-each-ref --format="%(refname:strip=0)" &&
-	test_must_fail git for-each-ref --format="%(refname:strip=-1)" &&
-	test_must_fail git for-each-ref --format="%(refname:strip=foo)"
-'
-
-test_expect_success 'stripping refnames too far gives an error' '
-	test_must_fail git for-each-ref --format="%(refname:strip=3)"
-'
-
 test_expect_success 'Check format specifiers are ignored in naming date atoms' '
 	git for-each-ref --format="%(authordate)" refs/heads &&
 	git for-each-ref --format="%(authordate:default) %(authordate)" refs/heads &&
@@ -164,6 +181,12 @@
 	test_must_fail git for-each-ref --format="%(authordate:INVALID)" refs/heads
 '
 
+test_expect_success 'arguments to %(objectname:short=) must be positive integers' '
+	test_must_fail git for-each-ref --format="%(objectname:short=0)" &&
+	test_must_fail git for-each-ref --format="%(objectname:short=-1)" &&
+	test_must_fail git for-each-ref --format="%(objectname:short=foo)"
+'
+
 test_date () {
 	f=$1 &&
 	committer_date=$2 &&
@@ -362,6 +385,8 @@
 
 test_atom head upstream:track '[ahead 1]'
 test_atom head upstream:trackshort '>'
+test_atom head upstream:track,nobracket 'ahead 1'
+test_atom head upstream:nobracket,track 'ahead 1'
 test_atom head push:track '[ahead 1]'
 test_atom head push:trackshort '>'
 
@@ -372,7 +397,7 @@
 
 test_expect_success 'Check that :track[short] works when upstream is invalid' '
 	cat >expected <<-\EOF &&
-
+	[gone]
 
 	EOF
 	test_when_finished "git config branch.master.merge refs/heads/master" &&
@@ -554,11 +579,12 @@
 	test_cmp expected actual
 '
 
+
 test_expect_success 'do not dereference NULL upon %(HEAD) on unborn branch' '
 	test_when_finished "git checkout master" &&
 	git for-each-ref --format="%(HEAD) %(refname:short)" refs/heads/ >actual &&
 	sed -e "s/^\* /  /" actual >expect &&
-	git checkout --orphan HEAD &&
+	git checkout --orphan orphaned-branch &&
 	git for-each-ref --format="%(HEAD) %(refname:short)" refs/heads/ >actual &&
 	test_cmp expect actual
 '
@@ -588,4 +614,52 @@
 	test_cmp expect actual.clean
 '
 
+test_expect_success 'Add symbolic ref for the following tests' '
+	git symbolic-ref refs/heads/sym refs/heads/master
+'
+
+cat >expected <<EOF
+refs/heads/master
+EOF
+
+test_expect_success 'Verify usage of %(symref) atom' '
+	git for-each-ref --format="%(symref)" refs/heads/sym >actual &&
+	test_cmp expected actual
+'
+
+cat >expected <<EOF
+heads/master
+EOF
+
+test_expect_success 'Verify usage of %(symref:short) atom' '
+	git for-each-ref --format="%(symref:short)" refs/heads/sym >actual &&
+	test_cmp expected actual
+'
+
+cat >expected <<EOF
+master
+heads/master
+EOF
+
+test_expect_success 'Verify usage of %(symref:lstrip) atom' '
+	git for-each-ref --format="%(symref:lstrip=2)" refs/heads/sym > actual &&
+	git for-each-ref --format="%(symref:lstrip=-2)" refs/heads/sym >> actual &&
+	test_cmp expected actual &&
+
+	git for-each-ref --format="%(symref:strip=2)" refs/heads/sym > actual &&
+	git for-each-ref --format="%(symref:strip=-2)" refs/heads/sym >> actual &&
+	test_cmp expected actual
+'
+
+cat >expected <<EOF
+refs
+refs/heads
+EOF
+
+test_expect_success 'Verify usage of %(symref:rstrip) atom' '
+	git for-each-ref --format="%(symref:rstrip=2)" refs/heads/sym > actual &&
+	git for-each-ref --format="%(symref:rstrip=-2)" refs/heads/sym >> actual &&
+	test_cmp expected actual
+'
+
 test_done
diff --git a/t/t6302-for-each-ref-filter.sh b/t/t6302-for-each-ref-filter.sh
index d0ab09f..a09a1a4 100755
--- a/t/t6302-for-each-ref-filter.sh
+++ b/t/t6302-for-each-ref-filter.sh
@@ -327,4 +327,98 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'improper usage of %(if), %(then), %(else) and %(end) atoms' '
+	test_must_fail git for-each-ref --format="%(if)" &&
+	test_must_fail git for-each-ref --format="%(then) %(end)" &&
+	test_must_fail git for-each-ref --format="%(else) %(end)" &&
+	test_must_fail git for-each-ref --format="%(if) %(else) %(end)" &&
+	test_must_fail git for-each-ref --format="%(if) %(then) %(then) %(end)" &&
+	test_must_fail git for-each-ref --format="%(then) %(else) %(end)" &&
+	test_must_fail git for-each-ref --format="%(if) %(else) %(end)" &&
+	test_must_fail git for-each-ref --format="%(if) %(then) %(else)" &&
+	test_must_fail git for-each-ref --format="%(if) %(else) %(then) %(end)" &&
+	test_must_fail git for-each-ref --format="%(if) %(then) %(else) %(else) %(end)" &&
+	test_must_fail git for-each-ref --format="%(if) %(end)"
+'
+
+test_expect_success 'check %(if)...%(then)...%(end) atoms' '
+	git for-each-ref --format="%(refname)%(if)%(authorname)%(then) Author: %(authorname)%(end)" >actual &&
+	cat >expect <<-\EOF &&
+	refs/heads/master Author: A U Thor
+	refs/heads/side Author: A U Thor
+	refs/odd/spot Author: A U Thor
+	refs/tags/annotated-tag
+	refs/tags/doubly-annotated-tag
+	refs/tags/doubly-signed-tag
+	refs/tags/foo1.10 Author: A U Thor
+	refs/tags/foo1.3 Author: A U Thor
+	refs/tags/foo1.6 Author: A U Thor
+	refs/tags/four Author: A U Thor
+	refs/tags/one Author: A U Thor
+	refs/tags/signed-tag
+	refs/tags/three Author: A U Thor
+	refs/tags/two Author: A U Thor
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'check %(if)...%(then)...%(else)...%(end) atoms' '
+	git for-each-ref --format="%(if)%(authorname)%(then)%(authorname)%(else)No author%(end): %(refname)" >actual &&
+	cat >expect <<-\EOF &&
+	A U Thor: refs/heads/master
+	A U Thor: refs/heads/side
+	A U Thor: refs/odd/spot
+	No author: refs/tags/annotated-tag
+	No author: refs/tags/doubly-annotated-tag
+	No author: refs/tags/doubly-signed-tag
+	A U Thor: refs/tags/foo1.10
+	A U Thor: refs/tags/foo1.3
+	A U Thor: refs/tags/foo1.6
+	A U Thor: refs/tags/four
+	A U Thor: refs/tags/one
+	No author: refs/tags/signed-tag
+	A U Thor: refs/tags/three
+	A U Thor: refs/tags/two
+	EOF
+	test_cmp expect actual
+'
+test_expect_success 'ignore spaces in %(if) atom usage' '
+	git for-each-ref --format="%(refname:short): %(if)%(HEAD)%(then)Head ref%(else)Not Head ref%(end)" >actual &&
+	cat >expect <<-\EOF &&
+	master: Head ref
+	side: Not Head ref
+	odd/spot: Not Head ref
+	annotated-tag: Not Head ref
+	doubly-annotated-tag: Not Head ref
+	doubly-signed-tag: Not Head ref
+	foo1.10: Not Head ref
+	foo1.3: Not Head ref
+	foo1.6: Not Head ref
+	four: Not Head ref
+	one: Not Head ref
+	signed-tag: Not Head ref
+	three: Not Head ref
+	two: Not Head ref
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'check %(if:equals=<string>)' '
+	git for-each-ref --format="%(if:equals=master)%(refname:short)%(then)Found master%(else)Not master%(end)" refs/heads/ >actual &&
+	cat >expect <<-\EOF &&
+	Found master
+	Not master
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'check %(if:notequals=<string>)' '
+	git for-each-ref --format="%(if:notequals=master)%(refname:short)%(then)Not master%(else)Found master%(end)" refs/heads/ >actual &&
+	cat >expect <<-\EOF &&
+	Found master
+	Not master
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t6500-gc.sh b/t/t6500-gc.sh
index 1762dfa..08de2e8 100755
--- a/t/t6500-gc.sh
+++ b/t/t6500-gc.sh
@@ -67,5 +67,20 @@
 	test_line_count = 2 new # There is one new pack and its .idx
 '
 
+test_expect_success 'background auto gc does not run if gc.log is present and recent but does if it is old' '
+	test_commit foo &&
+	test_commit bar &&
+	git repack &&
+	test_config gc.autopacklimit 1 &&
+	test_config gc.autodetach true &&
+	echo fleem >.git/gc.log &&
+	test_must_fail git gc --auto 2>err &&
+	test_i18ngrep "^error:" err &&
+	test_config gc.logexpiry 5.days &&
+	test-chmtime =-345600 .git/gc.log &&
+	test_must_fail git gc --auto &&
+	test_config gc.logexpiry 2.days &&
+	git gc --auto
+'
 
 test_done
diff --git a/t/t7003-filter-branch.sh b/t/t7003-filter-branch.sh
index cb8fbd8..7cb6079 100755
--- a/t/t7003-filter-branch.sh
+++ b/t/t7003-filter-branch.sh
@@ -313,6 +313,27 @@
 	git cat-file tag X/2 > actual &&
 	test_cmp expect actual
 '
+test_expect_success 'setup --prune-empty comparisons' '
+	git checkout --orphan master-no-a &&
+	git rm -rf . &&
+	unset test_tick &&
+	test_tick &&
+	GIT_COMMITTER_DATE="@0 +0000" GIT_AUTHOR_DATE="@0 +0000" &&
+	test_commit --notick B B.t B Bx &&
+	git checkout -b branch-no-a Bx &&
+	test_commit D D.t D Dx &&
+	mkdir dir &&
+	test_commit dir/D dir/D.t dir/D dir/Dx &&
+	test_commit E E.t E Ex &&
+	git checkout master-no-a &&
+	test_commit C C.t C Cx &&
+	git checkout branch-no-a &&
+	git merge Cx -m "Merge tag '\''C'\'' into branch" &&
+	git tag Fx &&
+	test_commit G G.t G Gx &&
+	test_commit H H.t H Hx &&
+	git checkout branch
+'
 
 test_expect_success 'Prune empty commits' '
 	git rev-list HEAD > expect &&
@@ -341,6 +362,22 @@
 	test_cmp expect actual
 '
 
+test_expect_success '--prune-empty is able to prune root commit' '
+	git rev-list branch-no-a >expect &&
+	git branch testing H &&
+	git filter-branch -f --prune-empty --index-filter "git update-index --remove A.t" testing &&
+	git rev-list testing >actual &&
+	git branch -D testing &&
+	test_cmp expect actual
+'
+
+test_expect_success '--prune-empty is able to prune entire branch' '
+	git branch prune-entire B &&
+	git filter-branch -f --prune-empty --index-filter "git update-index --remove A.t B.t" prune-entire &&
+	test_path_is_missing .git/refs/heads/prune-entire &&
+	test_must_fail git reflog exists refs/heads/prune-entire
+'
+
 test_expect_success '--remap-to-ancestor with filename filters' '
 	git checkout master &&
 	git reset --hard A &&
diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index 072e6c6..b4698ab 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -81,9 +81,25 @@
 '
 
 test_expect_success 'creating a tag with --create-reflog should create reflog' '
+	git log -1 \
+		--format="format:tag: tagging %h (%s, %cd)%n" \
+		--date=format:%Y-%m-%d >expected &&
 	test_when_finished "git tag -d tag_with_reflog" &&
 	git tag --create-reflog tag_with_reflog &&
-	git reflog exists refs/tags/tag_with_reflog
+	git reflog exists refs/tags/tag_with_reflog &&
+	sed -e "s/^.*	//" .git/logs/refs/tags/tag_with_reflog >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'annotated tag with --create-reflog has correct message' '
+	git log -1 \
+		--format="format:tag: tagging %h (%s, %cd)%n" \
+		--date=format:%Y-%m-%d >expected &&
+	test_when_finished "git tag -d tag_with_reflog" &&
+	git tag -m "annotated tag" --create-reflog tag_with_reflog &&
+	git reflog exists refs/tags/tag_with_reflog &&
+	sed -e "s/^.*	//" .git/logs/refs/tags/tag_with_reflog >actual &&
+	test_cmp expected actual
 '
 
 test_expect_success '--create-reflog does not create reflog on failure' '
diff --git a/t/t7518-ident-corner-cases.sh b/t/t7518-ident-corner-cases.sh
new file mode 100755
index 0000000..b22f631
--- /dev/null
+++ b/t/t7518-ident-corner-cases.sh
@@ -0,0 +1,36 @@
+#!/bin/sh
+
+test_description='corner cases in ident strings'
+. ./test-lib.sh
+
+# confirm that we do not segfault _and_ that we do not say "(null)", as
+# glibc systems will quietly handle our NULL pointer
+#
+# Note also that we can't use "env" here because we need to unset a variable,
+# and "-u" is not portable.
+test_expect_success 'empty name and missing email' '
+	(
+		sane_unset GIT_AUTHOR_EMAIL &&
+		GIT_AUTHOR_NAME= &&
+		test_must_fail git commit --allow-empty -m foo 2>err &&
+		test_i18ngrep ! null err
+	)
+'
+
+test_expect_success 'commit rejects all-crud name' '
+	test_must_fail env GIT_AUTHOR_NAME=" .;<>" \
+		git commit --allow-empty -m foo
+'
+
+# We must test the actual error message here, as an unwanted
+# auto-detection could fail for other reasons.
+test_expect_success 'empty configured name does not auto-detect' '
+	(
+		sane_unset GIT_AUTHOR_NAME &&
+		test_must_fail \
+			git -c user.name= commit --allow-empty -m foo 2>err &&
+		test_i18ngrep "empty ident name" err
+	)
+'
+
+test_done
diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index 19f0108..cee4209 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh
@@ -982,6 +982,72 @@
 	test_cmp expected actual
 '
 
+test_expect_success 'dashdash disambiguates rev as rev' '
+	test_when_finished "rm -f master" &&
+	echo content >master &&
+	echo master:hello.c >expect &&
+	git grep -l o master -- hello.c >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'dashdash disambiguates pathspec as pathspec' '
+	test_when_finished "git rm -f master" &&
+	echo content >master &&
+	git add master &&
+	echo master:content >expect &&
+	git grep o -- master >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'report bogus arg without dashdash' '
+	test_must_fail git grep o does-not-exist
+'
+
+test_expect_success 'report bogus rev with dashdash' '
+	test_must_fail git grep o hello.c --
+'
+
+test_expect_success 'allow non-existent path with dashdash' '
+	# We need a real match so grep exits with success.
+	tree=$(git ls-tree HEAD |
+	       sed s/hello.c/not-in-working-tree/ |
+	       git mktree) &&
+	git grep o "$tree" -- not-in-working-tree
+'
+
+test_expect_success 'grep --no-index pattern -- path' '
+	rm -fr non &&
+	mkdir -p non/git &&
+	(
+		GIT_CEILING_DIRECTORIES="$(pwd)/non" &&
+		export GIT_CEILING_DIRECTORIES &&
+		cd non/git &&
+		echo hello >hello &&
+		echo goodbye >goodbye &&
+		echo hello:hello >expect &&
+		git grep --no-index o -- hello >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'grep --no-index complains of revs' '
+	test_must_fail git grep --no-index o master -- 2>err &&
+	test_i18ngrep "cannot be used with revs" err
+'
+
+test_expect_success 'grep --no-index prefers paths to revs' '
+	test_when_finished "rm -f master" &&
+	echo content >master &&
+	echo master:content >expect &&
+	git grep --no-index o master >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'grep --no-index does not "diagnose" revs' '
+	test_must_fail git grep --no-index o :1:hello.c 2>err &&
+	test_i18ngrep ! -i "did you mean" err
+'
+
 cat >expected <<EOF
 hello.c:int main(int argc, const char **argv)
 hello.c:	printf("Hello world.\n");
diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
index 0f398dd..60a80f6 100755
--- a/t/t9001-send-email.sh
+++ b/t/t9001-send-email.sh
@@ -148,7 +148,6 @@
 !two@example.com!
 !three@example.com!
 !four@example.com!
-!five@example.com!
 EOF
 "
 
@@ -159,9 +158,9 @@
 	Test Cc: trailers.
 
 	Cc: one@example.com
-	Cc: <two@example.com> # this is part of the name
-	Cc: <three@example.com>, <four@example.com> # not.five@example.com
-	Cc: "Some # Body" <five@example.com> [part.of.name.too]
+	Cc: <two@example.com> # trailing comments are ignored
+	Cc: <three@example.com>, <not.four@example.com> one address per line
+	Cc: "Some # Body" <four@example.com> [ <also.a.comment> ]
 	EOF
 	clean_fake_sendmail &&
 	git send-email -1 --to=recipient@example.com \
diff --git a/t/t9200-git-cvsexportcommit.sh b/t/t9200-git-cvsexportcommit.sh
index bb879a5..1319415 100755
--- a/t/t9200-git-cvsexportcommit.sh
+++ b/t/t9200-git-cvsexportcommit.sh
@@ -18,6 +18,11 @@
     test_done
 fi
 
+if ! test_have_prereq NOT_ROOT; then
+	skip_all='When cvs is compiled with CVS_BADROOT commits as root fail'
+	test_done
+fi
+
 CVSROOT=$PWD/tmpcvsroot
 CVSWORK=$PWD/cvswork
 GIT_DIR=$PWD/.git
diff --git a/t/t9600-cvsimport.sh b/t/t9600-cvsimport.sh
index 4c384ff..804ce38 100755
--- a/t/t9600-cvsimport.sh
+++ b/t/t9600-cvsimport.sh
@@ -3,6 +3,11 @@
 test_description='git cvsimport basic tests'
 . ./lib-cvs.sh
 
+if ! test_have_prereq NOT_ROOT; then
+	skip_all='When cvs is compiled with CVS_BADROOT commits as root fail'
+	test_done
+fi
+
 test_expect_success PERL 'setup cvsroot environment' '
 	CVSROOT=$(pwd)/cvsroot &&
 	export CVSROOT
diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
index a34e55f..d711bef 100755
--- a/t/t9902-completion.sh
+++ b/t/t9902-completion.sh
@@ -98,7 +98,7 @@
 {
 	local -a COMPREPLY &&
 	sed -e 's/Z$//' >expected &&
-	cur="$1" &&
+	local cur="$1" &&
 	shift &&
 	__gitcomp "$@" &&
 	print_comp &&
@@ -113,7 +113,7 @@
 {
 	local -a COMPREPLY &&
 	sed -e 's/Z$//' >expected &&
-	cur="$1" &&
+	local cur="$1" &&
 	shift &&
 	__gitcomp_nl "$@" &&
 	print_comp &&
@@ -124,140 +124,280 @@
 
 actual="$TRASH_DIRECTORY/actual"
 
-test_expect_success 'setup for __gitdir tests' '
+if test_have_prereq MINGW
+then
+	ROOT="$(pwd -W)"
+else
+	ROOT="$(pwd)"
+fi
+
+test_expect_success 'setup for __git_find_repo_path/__gitdir tests' '
 	mkdir -p subdir/subsubdir &&
+	mkdir -p non-repo &&
 	git init otherrepo
 '
 
-test_expect_success '__gitdir - from command line (through $__git_dir)' '
-	echo "$TRASH_DIRECTORY/otherrepo/.git" >expected &&
+test_expect_success '__git_find_repo_path - from command line (through $__git_dir)' '
+	echo "$ROOT/otherrepo/.git" >expected &&
 	(
-		__git_dir="$TRASH_DIRECTORY/otherrepo/.git" &&
-		__gitdir >"$actual"
+		__git_dir="$ROOT/otherrepo/.git" &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - repo as argument' '
-	echo "otherrepo/.git" >expected &&
-	__gitdir "otherrepo" >"$actual" &&
-	test_cmp expected "$actual"
-'
-
-test_expect_success '__gitdir - remote as argument' '
-	echo "remote" >expected &&
-	__gitdir "remote" >"$actual" &&
-	test_cmp expected "$actual"
-'
-
-test_expect_success '__gitdir - .git directory in cwd' '
+test_expect_success '__git_find_repo_path - .git directory in cwd' '
 	echo ".git" >expected &&
-	__gitdir >"$actual" &&
+	(
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - .git directory in parent' '
-	echo "$(pwd -P)/.git" >expected &&
+test_expect_success '__git_find_repo_path - .git directory in parent' '
+	echo "$ROOT/.git" >expected &&
 	(
 		cd subdir/subsubdir &&
-		__gitdir >"$actual"
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - cwd is a .git directory' '
+test_expect_success '__git_find_repo_path - cwd is a .git directory' '
 	echo "." >expected &&
 	(
 		cd .git &&
-		__gitdir >"$actual"
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - parent is a .git directory' '
-	echo "$(pwd -P)/.git" >expected &&
+test_expect_success '__git_find_repo_path - parent is a .git directory' '
+	echo "$ROOT/.git" >expected &&
 	(
 		cd .git/refs/heads &&
-		__gitdir >"$actual"
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - $GIT_DIR set while .git directory in cwd' '
-	echo "$TRASH_DIRECTORY/otherrepo/.git" >expected &&
+test_expect_success '__git_find_repo_path - $GIT_DIR set while .git directory in cwd' '
+	echo "$ROOT/otherrepo/.git" >expected &&
 	(
-		GIT_DIR="$TRASH_DIRECTORY/otherrepo/.git" &&
+		GIT_DIR="$ROOT/otherrepo/.git" &&
 		export GIT_DIR &&
-		__gitdir >"$actual"
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - $GIT_DIR set while .git directory in parent' '
-	echo "$TRASH_DIRECTORY/otherrepo/.git" >expected &&
+test_expect_success '__git_find_repo_path - $GIT_DIR set while .git directory in parent' '
+	echo "$ROOT/otherrepo/.git" >expected &&
 	(
-		GIT_DIR="$TRASH_DIRECTORY/otherrepo/.git" &&
+		GIT_DIR="$ROOT/otherrepo/.git" &&
 		export GIT_DIR &&
 		cd subdir &&
-		__gitdir >"$actual"
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - non-existing $GIT_DIR' '
+test_expect_success '__git_find_repo_path - from command line while "git -C"' '
+	echo "$ROOT/.git" >expected &&
 	(
-		GIT_DIR="$TRASH_DIRECTORY/non-existing" &&
-		export GIT_DIR &&
-		test_must_fail __gitdir
-	)
+		__git_dir="$ROOT/.git" &&
+		__git_C_args=(-C otherrepo) &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
 '
 
-function pwd_P_W () {
-	if test_have_prereq MINGW
-	then
-		pwd -W
-	else
-		pwd -P
-	fi
-}
+test_expect_success '__git_find_repo_path - relative dir from command line and "git -C"' '
+	echo "$ROOT/otherrepo/.git" >expected &&
+	(
+		cd subdir &&
+		__git_dir="otherrepo/.git" &&
+		__git_C_args=(-C ..) &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
 
-test_expect_success '__gitdir - gitfile in cwd' '
-	echo "$(pwd_P_W)/otherrepo/.git" >expected &&
-	echo "gitdir: $(pwd_P_W)/otherrepo/.git" >subdir/.git &&
+test_expect_success '__git_find_repo_path - $GIT_DIR set while "git -C"' '
+	echo "$ROOT/.git" >expected &&
+	(
+		GIT_DIR="$ROOT/.git" &&
+		export GIT_DIR &&
+		__git_C_args=(-C otherrepo) &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_find_repo_path - relative dir in $GIT_DIR and "git -C"' '
+	echo "$ROOT/otherrepo/.git" >expected &&
+	(
+		cd subdir &&
+		GIT_DIR="otherrepo/.git" &&
+		export GIT_DIR &&
+		__git_C_args=(-C ..) &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_find_repo_path - "git -C" while .git directory in cwd' '
+	echo "$ROOT/otherrepo/.git" >expected &&
+	(
+		__git_C_args=(-C otherrepo) &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_find_repo_path - "git -C" while cwd is a .git directory' '
+	echo "$ROOT/otherrepo/.git" >expected &&
+	(
+		cd .git &&
+		__git_C_args=(-C .. -C otherrepo) &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_find_repo_path - "git -C" while .git directory in parent' '
+	echo "$ROOT/otherrepo/.git" >expected &&
+	(
+		cd subdir &&
+		__git_C_args=(-C .. -C otherrepo) &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_find_repo_path - non-existing path in "git -C"' '
+	(
+		__git_C_args=(-C non-existing) &&
+		test_must_fail __git_find_repo_path &&
+		printf "$__git_repo_path" >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_find_repo_path - non-existing path in $__git_dir' '
+	(
+		__git_dir="non-existing" &&
+		test_must_fail __git_find_repo_path &&
+		printf "$__git_repo_path" >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_find_repo_path - non-existing $GIT_DIR' '
+	(
+		GIT_DIR="$ROOT/non-existing" &&
+		export GIT_DIR &&
+		test_must_fail __git_find_repo_path &&
+		printf "$__git_repo_path" >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_find_repo_path - gitfile in cwd' '
+	echo "$ROOT/otherrepo/.git" >expected &&
+	echo "gitdir: $ROOT/otherrepo/.git" >subdir/.git &&
 	test_when_finished "rm -f subdir/.git" &&
 	(
 		cd subdir &&
-		__gitdir >"$actual"
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - gitfile in parent' '
-	echo "$(pwd_P_W)/otherrepo/.git" >expected &&
-	echo "gitdir: $(pwd_P_W)/otherrepo/.git" >subdir/.git &&
+test_expect_success '__git_find_repo_path - gitfile in parent' '
+	echo "$ROOT/otherrepo/.git" >expected &&
+	echo "gitdir: $ROOT/otherrepo/.git" >subdir/.git &&
 	test_when_finished "rm -f subdir/.git" &&
 	(
 		cd subdir/subsubdir &&
-		__gitdir >"$actual"
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success SYMLINKS '__gitdir - resulting path avoids symlinks' '
-	echo "$(pwd -P)/otherrepo/.git" >expected &&
+test_expect_success SYMLINKS '__git_find_repo_path - resulting path avoids symlinks' '
+	echo "$ROOT/otherrepo/.git" >expected &&
 	mkdir otherrepo/dir &&
 	test_when_finished "rm -rf otherrepo/dir" &&
 	ln -s otherrepo/dir link &&
 	test_when_finished "rm -f link" &&
 	(
 		cd link &&
+		__git_find_repo_path &&
+		echo "$__git_repo_path" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_find_repo_path - not a git repository' '
+	(
+		cd non-repo &&
+		GIT_CEILING_DIRECTORIES="$ROOT" &&
+		export GIT_CEILING_DIRECTORIES &&
+		test_must_fail __git_find_repo_path &&
+		printf "$__git_repo_path" >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__gitdir - finds repo' '
+	echo "$ROOT/.git" >expected &&
+	(
+		cd subdir/subsubdir &&
 		__gitdir >"$actual"
 	) &&
 	test_cmp expected "$actual"
 '
 
-test_expect_success '__gitdir - not a git repository' '
-	nongit test_must_fail __gitdir
+
+test_expect_success '__gitdir - returns error when cant find repo' '
+	(
+		__git_dir="non-existing" &&
+		test_must_fail __gitdir >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__gitdir - repo as argument' '
+	echo "otherrepo/.git" >expected &&
+	(
+		__gitdir "otherrepo" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__gitdir - remote as argument' '
+	echo "remote" >expected &&
+	(
+		__gitdir "remote" >"$actual"
+	) &&
+	test_cmp expected "$actual"
 '
 
 test_expect_success '__gitcomp - trailing space - options' '
@@ -361,10 +501,286 @@
 	git remote add remote_in_config_1 git://remote_1 &&
 	test_when_finished "git remote remove remote_in_config_2" &&
 	git remote add remote_in_config_2 git://remote_2 &&
-	__git_remotes >actual &&
+	(
+		__git_remotes >actual
+	) &&
 	test_cmp expect actual
 '
 
+test_expect_success '__git_is_configured_remote' '
+	test_when_finished "git remote remove remote_1" &&
+	git remote add remote_1 git://remote_1 &&
+	test_when_finished "git remote remove remote_2" &&
+	git remote add remote_2 git://remote_2 &&
+	(
+		verbose __git_is_configured_remote remote_2 &&
+		test_must_fail __git_is_configured_remote non-existent
+	)
+'
+
+test_expect_success 'setup for ref completion' '
+	git commit --allow-empty -m initial &&
+	git branch matching-branch &&
+	git tag matching-tag &&
+	(
+		cd otherrepo &&
+		git commit --allow-empty -m initial &&
+		git branch -m master master-in-other &&
+		git branch branch-in-other &&
+		git tag tag-in-other
+	) &&
+	git remote add other "$ROOT/otherrepo/.git" &&
+	git fetch --no-tags other &&
+	rm -f .git/FETCH_HEAD &&
+	git init thirdrepo
+'
+
+test_expect_success '__git_refs - simple' '
+	cat >expected <<-EOF &&
+	HEAD
+	master
+	matching-branch
+	other/branch-in-other
+	other/master-in-other
+	matching-tag
+	EOF
+	(
+		cur= &&
+		__git_refs >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - full refs' '
+	cat >expected <<-EOF &&
+	refs/heads/master
+	refs/heads/matching-branch
+	EOF
+	(
+		cur=refs/heads/ &&
+		__git_refs >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - repo given on the command line' '
+	cat >expected <<-EOF &&
+	HEAD
+	branch-in-other
+	master-in-other
+	tag-in-other
+	EOF
+	(
+		__git_dir="$ROOT/otherrepo/.git" &&
+		cur= &&
+		__git_refs >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - remote on local file system' '
+	cat >expected <<-EOF &&
+	HEAD
+	branch-in-other
+	master-in-other
+	tag-in-other
+	EOF
+	(
+		cur= &&
+		__git_refs otherrepo >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - remote on local file system - full refs' '
+	cat >expected <<-EOF &&
+	refs/heads/branch-in-other
+	refs/heads/master-in-other
+	refs/tags/tag-in-other
+	EOF
+	(
+		cur=refs/ &&
+		__git_refs otherrepo >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - configured remote' '
+	cat >expected <<-EOF &&
+	HEAD
+	branch-in-other
+	master-in-other
+	EOF
+	(
+		cur= &&
+		__git_refs other >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - configured remote - full refs' '
+	cat >expected <<-EOF &&
+	refs/heads/branch-in-other
+	refs/heads/master-in-other
+	refs/tags/tag-in-other
+	EOF
+	(
+		cur=refs/ &&
+		__git_refs other >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - configured remote - repo given on the command line' '
+	cat >expected <<-EOF &&
+	HEAD
+	branch-in-other
+	master-in-other
+	EOF
+	(
+		cd thirdrepo &&
+		__git_dir="$ROOT/.git" &&
+		cur= &&
+		__git_refs other >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - configured remote - full refs - repo given on the command line' '
+	cat >expected <<-EOF &&
+	refs/heads/branch-in-other
+	refs/heads/master-in-other
+	refs/tags/tag-in-other
+	EOF
+	(
+		cd thirdrepo &&
+		__git_dir="$ROOT/.git" &&
+		cur=refs/ &&
+		__git_refs other >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - configured remote - remote name matches a directory' '
+	cat >expected <<-EOF &&
+	HEAD
+	branch-in-other
+	master-in-other
+	EOF
+	mkdir other &&
+	test_when_finished "rm -rf other" &&
+	(
+		cur= &&
+		__git_refs other >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - URL remote' '
+	cat >expected <<-EOF &&
+	HEAD
+	branch-in-other
+	master-in-other
+	tag-in-other
+	EOF
+	(
+		cur= &&
+		__git_refs "file://$ROOT/otherrepo/.git" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - URL remote - full refs' '
+	cat >expected <<-EOF &&
+	refs/heads/branch-in-other
+	refs/heads/master-in-other
+	refs/tags/tag-in-other
+	EOF
+	(
+		cur=refs/ &&
+		__git_refs "file://$ROOT/otherrepo/.git" >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success '__git_refs - non-existing remote' '
+	(
+		cur= &&
+		__git_refs non-existing >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_refs - non-existing remote - full refs' '
+	(
+		cur=refs/ &&
+		__git_refs non-existing >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_refs - non-existing URL remote' '
+	(
+		cur= &&
+		__git_refs "file://$ROOT/non-existing" >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_refs - non-existing URL remote - full refs' '
+	(
+		cur=refs/ &&
+		__git_refs "file://$ROOT/non-existing" >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_refs - not in a git repository' '
+	(
+		GIT_CEILING_DIRECTORIES="$ROOT" &&
+		export GIT_CEILING_DIRECTORIES &&
+		cd subdir &&
+		cur= &&
+		__git_refs >"$actual"
+	) &&
+	test_must_be_empty "$actual"
+'
+
+test_expect_success '__git_refs - unique remote branches for git checkout DWIMery' '
+	cat >expected <<-EOF &&
+	HEAD
+	master
+	matching-branch
+	other/ambiguous
+	other/branch-in-other
+	other/master-in-other
+	remote/ambiguous
+	remote/branch-in-remote
+	matching-tag
+	branch-in-other
+	branch-in-remote
+	master-in-other
+	EOF
+	for remote_ref in refs/remotes/other/ambiguous \
+		refs/remotes/remote/ambiguous \
+		refs/remotes/remote/branch-in-remote
+	do
+		git update-ref $remote_ref master &&
+		test_when_finished "git update-ref -d $remote_ref"
+	done &&
+	(
+		cur= &&
+		__git_refs "" 1 >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success 'teardown after ref completion' '
+	git branch -d matching-branch &&
+	git tag -d matching-tag &&
+	git remote remove other
+'
+
 test_expect_success '__git_get_config_variables' '
 	cat >expect <<-EOF &&
 	name-1
@@ -475,7 +891,12 @@
 	test_completion "git --namespace=foo check" "checkout " &&
 	test_completion "git --paginate check" "checkout " &&
 	test_completion "git --info-path check" "checkout " &&
-	test_completion "git --no-replace-objects check" "checkout "
+	test_completion "git --no-replace-objects check" "checkout " &&
+	test_completion "git --git-dir some/path check" "checkout " &&
+	test_completion "git -c conf.var=value check" "checkout " &&
+	test_completion "git -C some/path check" "checkout " &&
+	test_completion "git --work-tree some/path check" "checkout " &&
+	test_completion "git --namespace name/space check" "checkout "
 '
 
 test_expect_success 'git --help completion' '
@@ -483,10 +904,10 @@
 	test_completion "git --help core" "core-tutorial "
 '
 
-test_expect_success 'setup for ref completion' '
+test_expect_success 'setup for integration tests' '
 	echo content >file1 &&
 	echo more >file2 &&
-	git add . &&
+	git add file1 file2 &&
 	git commit -m one &&
 	git branch mybranch &&
 	git tag mytag
@@ -500,6 +921,12 @@
 	EOF
 '
 
+test_expect_success 'git -C <path> checkout uses the right repo' '
+	test_completion "git -C subdir -C subsubdir -C .. -C ../otherrepo checkout b" <<-\EOF
+	branch-in-other Z
+	EOF
+'
+
 test_expect_success 'show completes all refs' '
 	test_completion "git show m" <<-\EOF
 	master Z
@@ -517,7 +944,7 @@
 
 test_expect_success 'complete tree filename with spaces' '
 	echo content >"name with spaces" &&
-	git add . &&
+	git add "name with spaces" &&
 	git commit -m spaces &&
 	test_completion "git show HEAD:nam" <<-\EOF
 	name with spaces Z
@@ -526,7 +953,7 @@
 
 test_expect_success 'complete tree filename with metacharacters' '
 	echo content >"name with \${meta}" &&
-	git add . &&
+	git add "name with \${meta}" &&
 	git commit -m meta &&
 	test_completion "git show HEAD:nam" <<-\EOF
 	name with ${meta} Z
diff --git a/tempfile.c b/tempfile.c
index ffcc272..6843710 100644
--- a/tempfile.c
+++ b/tempfile.c
@@ -247,8 +247,13 @@
 	tempfile->fd = -1;
 	if (fp) {
 		tempfile->fp = NULL;
-		err = ferror(fp);
-		err |= fclose(fp);
+		if (ferror(fp)) {
+			err = -1;
+			if (!fclose(fp))
+				errno = EIO;
+		} else {
+			err = fclose(fp);
+		}
 	} else {
 		err = close(fd);
 	}
diff --git a/transport-helper.c b/transport-helper.c
index 1258d6a..dc90a1f 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -124,8 +124,9 @@
 	helper->git_cmd = 0;
 	helper->silent_exec_failure = 1;
 
-	argv_array_pushf(&helper->env_array, "%s=%s", GIT_DIR_ENVIRONMENT,
-			 get_git_dir());
+	if (have_git_dir())
+		argv_array_pushf(&helper->env_array, "%s=%s",
+				 GIT_DIR_ENVIRONMENT, get_git_dir());
 
 	code = start_command(helper);
 	if (code < 0 && errno == ENOENT)
diff --git a/transport.c b/transport.c
index d72e089..417ed7f 100644
--- a/transport.c
+++ b/transport.c
@@ -204,6 +204,7 @@
 static int fetch_refs_via_pack(struct transport *transport,
 			       int nr_heads, struct ref **to_fetch)
 {
+	int ret = 0;
 	struct git_transport_data *data = transport->data;
 	struct ref *refs;
 	char *dest = xstrdup(transport->url);
@@ -241,19 +242,22 @@
 			  &transport->pack_lockfile);
 	close(data->fd[0]);
 	close(data->fd[1]);
-	if (finish_connect(data->conn)) {
-		free_refs(refs);
-		refs = NULL;
-	}
+	if (finish_connect(data->conn))
+		ret = -1;
 	data->conn = NULL;
 	data->got_remote_heads = 0;
 	data->options.self_contained_and_connected =
 		args.self_contained_and_connected;
 
+	if (refs == NULL)
+		ret = -1;
+	if (report_unmatched_refs(to_fetch, nr_heads))
+		ret = -1;
+
 	free_refs(refs_tmp);
 	free_refs(refs);
 	free(dest);
-	return (refs ? 0 : -1);
+	return ret;
 }
 
 static int push_had_errors(struct ref *ref)
@@ -299,7 +303,7 @@
 		if (verbose)
 			fprintf(stderr, "updating local tracking ref '%s'\n", rs.dst);
 		if (ref->deletion) {
-			delete_ref(rs.dst, NULL, 0);
+			delete_ref(NULL, rs.dst, NULL, 0);
 		} else
 			update_ref("update by push", rs.dst,
 					ref->new_oid.hash, NULL, 0, 0);
@@ -467,11 +471,11 @@
 {
 	struct ref *ref;
 	int n = 0;
-	unsigned char head_sha1[20];
+	struct object_id head_oid;
 	char *head;
 	int summary_width = transport_summary_width(refs);
 
-	head = resolve_refdup("HEAD", RESOLVE_REF_READING, head_sha1, NULL);
+	head = resolve_refdup("HEAD", RESOLVE_REF_READING, head_oid.hash, NULL);
 
 	if (verbose) {
 		for (ref = refs; ref; ref = ref->next)
@@ -1206,6 +1210,42 @@
 	return xstrdup(url);
 }
 
+static void read_alternate_refs(const char *path,
+				alternate_ref_fn *cb,
+				void *data)
+{
+	struct child_process cmd = CHILD_PROCESS_INIT;
+	struct strbuf line = STRBUF_INIT;
+	FILE *fh;
+
+	cmd.git_cmd = 1;
+	argv_array_pushf(&cmd.args, "--git-dir=%s", path);
+	argv_array_push(&cmd.args, "for-each-ref");
+	argv_array_push(&cmd.args, "--format=%(objectname) %(refname)");
+	cmd.env = local_repo_env;
+	cmd.out = -1;
+
+	if (start_command(&cmd))
+		return;
+
+	fh = xfdopen(cmd.out, "r");
+	while (strbuf_getline_lf(&line, fh) != EOF) {
+		struct object_id oid;
+
+		if (get_oid_hex(line.buf, &oid) ||
+		    line.buf[GIT_SHA1_HEXSZ] != ' ') {
+			warning("invalid line while parsing alternate refs: %s",
+				line.buf);
+			break;
+		}
+
+		cb(line.buf + GIT_SHA1_HEXSZ + 1, &oid, data);
+	}
+
+	fclose(fh);
+	finish_command(&cmd);
+}
+
 struct alternate_refs_data {
 	alternate_ref_fn *fn;
 	void *data;
@@ -1214,34 +1254,26 @@
 static int refs_from_alternate_cb(struct alternate_object_database *e,
 				  void *data)
 {
-	char *other;
-	size_t len;
-	struct remote *remote;
-	struct transport *transport;
-	const struct ref *extra;
+	struct strbuf path = STRBUF_INIT;
+	size_t base_len;
 	struct alternate_refs_data *cb = data;
 
-	other = real_pathdup(e->path);
-	len = strlen(other);
+	if (!strbuf_realpath(&path, e->path, 0))
+		goto out;
+	if (!strbuf_strip_suffix(&path, "/objects"))
+		goto out;
+	base_len = path.len;
 
-	while (other[len-1] == '/')
-		other[--len] = '\0';
-	if (len < 8 || memcmp(other + len - 8, "/objects", 8))
-		goto out;
 	/* Is this a git repository with refs? */
-	memcpy(other + len - 8, "/refs", 6);
-	if (!is_directory(other))
+	strbuf_addstr(&path, "/refs");
+	if (!is_directory(path.buf))
 		goto out;
-	other[len - 8] = '\0';
-	remote = remote_get(other);
-	transport = transport_get(remote, other);
-	for (extra = transport_get_remote_refs(transport);
-	     extra;
-	     extra = extra->next)
-		cb->fn(extra, cb->data);
-	transport_disconnect(transport);
+	strbuf_setlen(&path, base_len);
+
+	read_alternate_refs(path.buf, cb->fn, cb->data);
+
 out:
-	free(other);
+	strbuf_release(&path);
 	return 0;
 }
 
diff --git a/transport.h b/transport.h
index e597b31..bc55715 100644
--- a/transport.h
+++ b/transport.h
@@ -255,6 +255,6 @@
 void transport_print_push_status(const char *dest, struct ref *refs,
 		  int verbose, int porcelain, unsigned int *reject_reasons);
 
-typedef void alternate_ref_fn(const struct ref *, void *);
+typedef void alternate_ref_fn(const char *refname, const struct object_id *oid, void *);
 extern void for_each_alternate_ref(alternate_ref_fn, void *);
 #endif
diff --git a/upload-pack.c b/upload-pack.c
index 7597ba3..ffb028d 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -822,9 +822,13 @@
 			use_include_tag = 1;
 
 		o = parse_object(sha1_buf);
-		if (!o)
+		if (!o) {
+			packet_write_fmt(1,
+					 "ERR upload-pack: not our ref %s",
+					 sha1_to_hex(sha1_buf));
 			die("git upload-pack: not our ref %s",
 			    sha1_to_hex(sha1_buf));
+		}
 		if (!(o->flags & WANTED)) {
 			o->flags |= WANTED;
 			if (!((allow_unadvertised_object_request & ALLOW_ANY_SHA1) == ALLOW_ANY_SHA1
diff --git a/urlmatch.c b/urlmatch.c
index 132d342..4bbde92 100644
--- a/urlmatch.c
+++ b/urlmatch.c
@@ -63,7 +63,50 @@
 	return 1;
 }
 
-char *url_normalize(const char *url, struct url_info *out_info)
+static const char *end_of_token(const char *s, int c, size_t n)
+{
+	const char *next = memchr(s, c, n);
+	if (!next)
+		next = s + n;
+	return next;
+}
+
+static int match_host(const struct url_info *url_info,
+		      const struct url_info *pattern_info)
+{
+	const char *url = url_info->url + url_info->host_off;
+	const char *pat = pattern_info->url + pattern_info->host_off;
+	int url_len = url_info->host_len;
+	int pat_len = pattern_info->host_len;
+
+	while (url_len && pat_len) {
+		const char *url_next = end_of_token(url, '.', url_len);
+		const char *pat_next = end_of_token(pat, '.', pat_len);
+
+		if (pat_next == pat + 1 && pat[0] == '*')
+			/* wildcard matches anything */
+			;
+		else if ((pat_next - pat) == (url_next - url) &&
+			 !memcmp(url, pat, url_next - url))
+			/* the components are the same */
+			;
+		else
+			return 0; /* found an unmatch */
+
+		if (url_next < url + url_len)
+			url_next++;
+		url_len -= url_next - url;
+		url = url_next;
+		if (pat_next < pat + pat_len)
+			pat_next++;
+		pat_len -= pat_next - pat;
+		pat = pat_next;
+	}
+
+	return (!url_len && !pat_len);
+}
+
+static char *url_normalize_1(const char *url, struct url_info *out_info, char allow_globs)
 {
 	/*
 	 * Normalize NUL-terminated url using the following rules:
@@ -104,7 +147,7 @@
 	struct strbuf norm;
 	size_t spanned;
 	size_t scheme_len, user_off=0, user_len=0, passwd_off=0, passwd_len=0;
-	size_t host_off=0, host_len=0, port_len=0, path_off, path_len, result_len;
+	size_t host_off=0, host_len=0, port_off=0, port_len=0, path_off, path_len, result_len;
 	const char *slash_ptr, *at_ptr, *colon_ptr, *path_start;
 	char *result;
 
@@ -191,7 +234,12 @@
 		strbuf_release(&norm);
 		return NULL;
 	}
-	spanned = strspn(url, URL_HOST_CHARS);
+
+	if (allow_globs)
+		spanned = strspn(url, URL_HOST_CHARS "*");
+	else
+		spanned = strspn(url, URL_HOST_CHARS);
+
 	if (spanned < colon_ptr - url) {
 		/* Host name has invalid characters */
 		if (out_info) {
@@ -258,6 +306,7 @@
 				return NULL;
 			}
 			strbuf_addch(&norm, ':');
+			port_off = norm.len;
 			strbuf_add(&norm, url, slash_ptr - url);
 			port_len = slash_ptr - url;
 		}
@@ -265,7 +314,7 @@
 		url = slash_ptr;
 	}
 	if (host_off)
-		host_len = norm.len - host_off;
+		host_len = norm.len - host_off - (port_len ? port_len + 1 : 0);
 
 
 	/*
@@ -373,6 +422,7 @@
 		out_info->passwd_len = passwd_len;
 		out_info->host_off = host_off;
 		out_info->host_len = host_len;
+		out_info->port_off = port_off;
 		out_info->port_len = port_len;
 		out_info->path_off = path_off;
 		out_info->path_len = path_len;
@@ -380,6 +430,11 @@
 	return result;
 }
 
+char *url_normalize(const char *url, struct url_info *out_info)
+{
+	return url_normalize_1(url, out_info, 0);
+}
+
 static size_t url_match_prefix(const char *url,
 			       const char *url_prefix,
 			       size_t url_prefix_len)
@@ -414,7 +469,7 @@
 
 static int match_urls(const struct url_info *url,
 		      const struct url_info *url_prefix,
-		      int *exactusermatch)
+		      struct urlmatch_item *match)
 {
 	/*
 	 * url_prefix matches url if the scheme, host and port of url_prefix
@@ -433,8 +488,8 @@
 	 * contained a user name or false if url_prefix did not have a
 	 * user name.  If there is no match *exactusermatch is left untouched.
 	 */
-	int usermatched = 0;
-	int pathmatchlen;
+	char usermatched = 0;
+	size_t pathmatchlen;
 
 	if (!url || !url_prefix || !url->url || !url_prefix->url)
 		return 0;
@@ -454,33 +509,53 @@
 		usermatched = 1;
 	}
 
-	/* check the host and port */
-	if (url_prefix->host_len != url->host_len ||
-	    strncmp(url->url + url->host_off,
-		    url_prefix->url + url_prefix->host_off, url->host_len))
-		return 0; /* host names and/or ports do not match */
+	/* check the host */
+	if (!match_host(url, url_prefix))
+		return 0; /* host names do not match */
+
+	/* check the port */
+	if (url_prefix->port_len != url->port_len ||
+	    strncmp(url->url + url->port_off,
+		    url_prefix->url + url_prefix->port_off, url->port_len))
+		return 0; /* ports do not match */
 
 	/* check the path */
 	pathmatchlen = url_match_prefix(
 		url->url + url->path_off,
 		url_prefix->url + url_prefix->path_off,
 		url_prefix->url_len - url_prefix->path_off);
+	if (!pathmatchlen)
+		return 0; /* paths do not match */
 
-	if (pathmatchlen && exactusermatch)
-		*exactusermatch = usermatched;
-	return pathmatchlen;
+	if (match) {
+		match->hostmatch_len = url_prefix->host_len;
+		match->pathmatch_len = pathmatchlen;
+		match->user_matched = usermatched;
+	}
+
+	return 1;
+}
+
+static int cmp_matches(const struct urlmatch_item *a,
+		       const struct urlmatch_item *b)
+{
+	if (a->hostmatch_len != b->hostmatch_len)
+		return a->hostmatch_len < b->hostmatch_len ? -1 : 1;
+	if (a->pathmatch_len != b->pathmatch_len)
+		return a->pathmatch_len < b->pathmatch_len ? -1 : 1;
+	if (a->user_matched != b->user_matched)
+		return b->user_matched ? -1 : 1;
+	return 0;
 }
 
 int urlmatch_config_entry(const char *var, const char *value, void *cb)
 {
 	struct string_list_item *item;
 	struct urlmatch_config *collect = cb;
-	struct urlmatch_item *matched;
+	struct urlmatch_item matched = {0};
 	struct url_info *url = &collect->url;
 	const char *key, *dot;
 	struct strbuf synthkey = STRBUF_INIT;
-	size_t matched_len = 0;
-	int user_matched = 0;
 	int retval;
 
 	if (!skip_prefix(var, collect->section, &key) || *(key++) != '.') {
@@ -494,13 +569,13 @@
 		struct url_info norm_info;
 
 		config_url = xmemdupz(key, dot - key);
-		norm_url = url_normalize(config_url, &norm_info);
+		norm_url = url_normalize_1(config_url, &norm_info, 1);
 		free(config_url);
 		if (!norm_url)
 			return 0;
-		matched_len = match_urls(url, &norm_info, &user_matched);
+		retval = match_urls(url, &norm_info, &matched);
 		free(norm_url);
-		if (!matched_len)
+		if (!retval)
 			return 0;
 		key = dot + 1;
 	}
@@ -510,24 +585,18 @@
 
 	item = string_list_insert(&collect->vars, key);
 	if (!item->util) {
-		matched = xcalloc(1, sizeof(*matched));
-		item->util = matched;
+		item->util = xcalloc(1, sizeof(matched));
 	} else {
-		matched = item->util;
-		/*
-		 * Is our match shorter?  Is our match the same
-		 * length, and without user while the current
-		 * candidate is with user?  Then we cannot use it.
-		 */
-		if (matched_len < matched->matched_len ||
-		    ((matched_len == matched->matched_len) &&
-		     (!user_matched && matched->user_matched)))
+		if (cmp_matches(&matched, item->util) < 0)
+			 /*
+			  * Our match is worse than the old one,
+			  * we cannot use it.
+			  */
 			return 0;
 		/* Otherwise, replace it with this one. */
 	}
 
-	matched->matched_len = matched_len;
-	matched->user_matched = user_matched;
+	memcpy(item->util, &matched, sizeof(matched));
 	strbuf_addstr(&synthkey, collect->section);
 	strbuf_addch(&synthkey, '.');
 	strbuf_addstr(&synthkey, key);
diff --git a/urlmatch.h b/urlmatch.h
index 528862a..37ee5da 100644
--- a/urlmatch.h
+++ b/urlmatch.h
@@ -18,11 +18,12 @@
 	size_t passwd_len;	/* length of passwd; if passwd_off != 0 but
 				   passwd_len == 0, an empty passwd was given */
 	size_t host_off;	/* offset into url to start of host name (0 => none) */
-	size_t host_len;	/* length of host name; this INCLUDES any ':portnum';
+	size_t host_len;	/* length of host name;
 				 * file urls may have host_len == 0 */
-	size_t port_len;	/* if a portnum is present (port_len != 0), it has
-				 * this length (excluding the leading ':') at the
-				 * end of the host name (always 0 for file urls) */
+	size_t port_off;	/* offset into url to start of port number (0 => none) */
+	size_t port_len;	/* if a portnum is present (port_off != 0), it has
+				 * this length (excluding the leading ':') starting
+				 * from port_off (always 0 for file urls) */
 	size_t path_off;	/* offset into url to the start of the url path;
 				 * this will always point to a '/' character
 				 * after the url has been normalized */
@@ -33,7 +34,8 @@
 extern char *url_normalize(const char *, struct url_info *);
 
 struct urlmatch_item {
-	size_t matched_len;
+	size_t hostmatch_len;
+	size_t pathmatch_len;
 	char user_matched;
 };
 
diff --git a/userdiff.c b/userdiff.c
index 2125d6d..8b732e4 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -262,25 +262,22 @@
 
 struct userdiff_driver *userdiff_find_by_path(const char *path)
 {
-	static struct git_attr *attr;
-	struct git_attr_check check;
+	static struct attr_check *check;
 
-	if (!attr)
-		attr = git_attr("diff");
-	check.attr = attr;
-
+	if (!check)
+		check = attr_check_initl("diff", NULL);
 	if (!path)
 		return NULL;
-	if (git_check_attr(path, 1, &check))
+	if (git_check_attr(path, check))
 		return NULL;
 
-	if (ATTR_TRUE(check.value))
+	if (ATTR_TRUE(check->items[0].value))
 		return &driver_true;
-	if (ATTR_FALSE(check.value))
+	if (ATTR_FALSE(check->items[0].value))
 		return &driver_false;
-	if (ATTR_UNSET(check.value))
+	if (ATTR_UNSET(check->items[0].value))
 		return NULL;
-	return userdiff_find_by_name(check.value);
+	return userdiff_find_by_name(check->items[0].value);
 }
 
 struct userdiff_driver *userdiff_get_textconv(struct userdiff_driver *driver)
diff --git a/worktree.c b/worktree.c
index d633761..fa7bc67 100644
--- a/worktree.c
+++ b/worktree.c
@@ -175,7 +175,7 @@
 	struct dirent *d;
 	int counter = 0, alloc = 2;
 
-	list = xmalloc(alloc * sizeof(struct worktree *));
+	ALLOC_ARRAY(list, alloc);
 
 	list[counter++] = get_main_worktree();
 
@@ -255,7 +255,7 @@
 		return wt;
 
 	arg = prefix_filename(prefix, strlen(prefix), arg);
-	path = real_pathdup(arg);
+	path = real_pathdup(arg, 1);
 	for (; *list; list++)
 		if (!fspathcmp(path, real_path((*list)->path)))
 			break;
diff --git a/wrapper.c b/wrapper.c
index e7f1979..0542fc7 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -440,23 +440,6 @@
 	return fd;
 }
 
-/* git_mkstemp() - create tmp file honoring TMPDIR variable */
-int git_mkstemp(char *path, size_t len, const char *template)
-{
-	const char *tmp;
-	size_t n;
-
-	tmp = getenv("TMPDIR");
-	if (!tmp)
-		tmp = "/tmp";
-	n = snprintf(path, len, "%s/%s", tmp, template);
-	if (len <= n) {
-		errno = ENAMETOOLONG;
-		return -1;
-	}
-	return mkstemp(path);
-}
-
 /* Adapted from libiberty's mkstemp.c. */
 
 #undef TMP_MAX
@@ -531,13 +514,6 @@
 	return git_mkstemps_mode(pattern, 0, mode);
 }
 
-#ifdef NO_MKSTEMPS
-int gitmkstemps(char *pattern, int suffix_len)
-{
-	return git_mkstemps_mode(pattern, suffix_len, 0600);
-}
-#endif
-
 int xmkstemp_mode(char *template, int mode)
 {
 	int fd;
diff --git a/ws.c b/ws.c
index ea4b2b1..a07caed 100644
--- a/ws.c
+++ b/ws.c
@@ -71,24 +71,17 @@
 	return rule;
 }
 
-static void setup_whitespace_attr_check(struct git_attr_check *check)
-{
-	static struct git_attr *attr_whitespace;
-
-	if (!attr_whitespace)
-		attr_whitespace = git_attr("whitespace");
-	check[0].attr = attr_whitespace;
-}
-
 unsigned whitespace_rule(const char *pathname)
 {
-	struct git_attr_check attr_whitespace_rule;
+	static struct attr_check *attr_whitespace_rule;
 
-	setup_whitespace_attr_check(&attr_whitespace_rule);
-	if (!git_check_attr(pathname, 1, &attr_whitespace_rule)) {
+	if (!attr_whitespace_rule)
+		attr_whitespace_rule = attr_check_initl("whitespace", NULL);
+
+	if (!git_check_attr(pathname, attr_whitespace_rule)) {
 		const char *value;
 
-		value = attr_whitespace_rule.value;
+		value = attr_whitespace_rule->items[0].value;
 		if (ATTR_TRUE(value)) {
 			/* true (whitespace) */
 			unsigned all_rule = ws_tab_width(whitespace_rule_cfg);
diff --git a/wt-status.c b/wt-status.c
index d470120..cc446f2 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -121,7 +121,7 @@
 
 void wt_status_prepare(struct wt_status *s)
 {
-	unsigned char sha1[20];
+	struct object_id oid;
 
 	memset(s, 0, sizeof(*s));
 	memcpy(s->color_palette, default_wt_status_colors,
@@ -129,7 +129,7 @@
 	s->show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
 	s->use_color = -1;
 	s->relative_paths = 1;
-	s->branch = resolve_refdup("HEAD", 0, sha1, NULL);
+	s->branch = resolve_refdup("HEAD", 0, oid.hash, NULL);
 	s->reference = "HEAD";
 	s->fp = stdout;
 	s->index_file = get_index_file();
@@ -1115,16 +1115,16 @@
 
 	split = strbuf_split_max(line, ' ', 3);
 	if (split[0] && split[1]) {
-		unsigned char sha1[20];
+		struct object_id oid;
 
 		/*
 		 * strbuf_split_max left a space. Trim it and re-add
 		 * it after abbreviation.
 		 */
 		strbuf_trim(split[1]);
-		if (!get_sha1(split[1]->buf, sha1)) {
+		if (!get_oid(split[1]->buf, &oid)) {
 			strbuf_reset(split[1]);
-			strbuf_add_unique_abbrev(split[1], sha1,
+			strbuf_add_unique_abbrev(split[1], oid.hash,
 						 DEFAULT_ABBREV);
 			strbuf_addch(split[1], ' ');
 			strbuf_reset(line);
@@ -1340,7 +1340,7 @@
 static char *get_branch(const struct worktree *wt, const char *path)
 {
 	struct strbuf sb = STRBUF_INIT;
-	unsigned char sha1[20];
+	struct object_id oid;
 	const char *branch_name;
 
 	if (strbuf_read_file(&sb, worktree_git_path(wt, "%s", path), 0) <= 0)
@@ -1354,9 +1354,9 @@
 		strbuf_remove(&sb, 0, branch_name - sb.buf);
 	else if (starts_with(sb.buf, "refs/"))
 		;
-	else if (!get_sha1_hex(sb.buf, sha1)) {
+	else if (!get_oid_hex(sb.buf, &oid)) {
 		strbuf_reset(&sb);
-		strbuf_add_unique_abbrev(&sb, sha1, DEFAULT_ABBREV);
+		strbuf_add_unique_abbrev(&sb, oid.hash, DEFAULT_ABBREV);
 	} else if (!strcmp(sb.buf, "detached HEAD")) /* rebase */
 		goto got_nothing;
 	else			/* bisect */
@@ -1370,10 +1370,10 @@
 
 struct grab_1st_switch_cbdata {
 	struct strbuf buf;
-	unsigned char nsha1[20];
+	struct object_id noid;
 };
 
-static int grab_1st_switch(unsigned char *osha1, unsigned char *nsha1,
+static int grab_1st_switch(struct object_id *ooid, struct object_id *noid,
 			   const char *email, unsigned long timestamp, int tz,
 			   const char *message, void *cb_data)
 {
@@ -1387,13 +1387,13 @@
 		return 0;
 	target += strlen(" to ");
 	strbuf_reset(&cb->buf);
-	hashcpy(cb->nsha1, nsha1);
+	oidcpy(&cb->noid, noid);
 	end = strchrnul(target, '\n');
 	strbuf_add(&cb->buf, target, end - target);
 	if (!strcmp(cb->buf.buf, "HEAD")) {
 		/* HEAD is relative. Resolve it to the right reflog entry. */
 		strbuf_reset(&cb->buf);
-		strbuf_add_unique_abbrev(&cb->buf, nsha1, DEFAULT_ABBREV);
+		strbuf_add_unique_abbrev(&cb->buf, noid->hash, DEFAULT_ABBREV);
 	}
 	return 1;
 }
@@ -1402,7 +1402,7 @@
 {
 	struct grab_1st_switch_cbdata cb;
 	struct commit *commit;
-	unsigned char sha1[20];
+	struct object_id oid;
 	char *ref = NULL;
 
 	strbuf_init(&cb.buf, 0);
@@ -1411,22 +1411,22 @@
 		return;
 	}
 
-	if (dwim_ref(cb.buf.buf, cb.buf.len, sha1, &ref) == 1 &&
+	if (dwim_ref(cb.buf.buf, cb.buf.len, oid.hash, &ref) == 1 &&
 	    /* sha1 is a commit? match without further lookup */
-	    (!hashcmp(cb.nsha1, sha1) ||
+	    (!oidcmp(&cb.noid, &oid) ||
 	     /* perhaps sha1 is a tag, try to dereference to a commit */
-	     ((commit = lookup_commit_reference_gently(sha1, 1)) != NULL &&
-	      !hashcmp(cb.nsha1, commit->object.oid.hash)))) {
+	     ((commit = lookup_commit_reference_gently(oid.hash, 1)) != NULL &&
+	      !oidcmp(&cb.noid, &commit->object.oid)))) {
 		const char *from = ref;
 		if (!skip_prefix(from, "refs/tags/", &from))
 			skip_prefix(from, "refs/remotes/", &from);
 		state->detached_from = xstrdup(from);
 	} else
 		state->detached_from =
-			xstrdup(find_unique_abbrev(cb.nsha1, DEFAULT_ABBREV));
-	hashcpy(state->detached_sha1, cb.nsha1);
-	state->detached_at = !get_sha1("HEAD", sha1) &&
-			     !hashcmp(sha1, state->detached_sha1);
+			xstrdup(find_unique_abbrev(cb.noid.hash, DEFAULT_ABBREV));
+	hashcpy(state->detached_sha1, cb.noid.hash);
+	state->detached_at = !get_oid("HEAD", &oid) &&
+			     !hashcmp(oid.hash, state->detached_sha1);
 
 	free(ref);
 	strbuf_release(&cb.buf);
@@ -1476,22 +1476,22 @@
 			 int get_detached_from)
 {
 	struct stat st;
-	unsigned char sha1[20];
+	struct object_id oid;
 
 	if (!stat(git_path_merge_head(), &st)) {
 		state->merge_in_progress = 1;
 	} else if (wt_status_check_rebase(NULL, state)) {
 		;		/* all set */
 	} else if (!stat(git_path_cherry_pick_head(), &st) &&
-			!get_sha1("CHERRY_PICK_HEAD", sha1)) {
+			!get_oid("CHERRY_PICK_HEAD", &oid)) {
 		state->cherry_pick_in_progress = 1;
-		hashcpy(state->cherry_pick_head_sha1, sha1);
+		hashcpy(state->cherry_pick_head_sha1, oid.hash);
 	}
 	wt_status_check_bisect(NULL, state);
 	if (!stat(git_path_revert_head(), &st) &&
-	    !get_sha1("REVERT_HEAD", sha1)) {
+	    !get_oid("REVERT_HEAD", &oid)) {
 		state->revert_in_progress = 1;
-		hashcpy(state->revert_head_sha1, sha1);
+		hashcpy(state->revert_head_sha1, oid.hash);
 	}
 
 	if (get_detached_from)
@@ -1730,12 +1730,14 @@
 		return;
 	branch_name = s->branch;
 
+#define LABEL(string) (s->no_gettext ? (string) : _(string))
+
 	if (s->is_initial)
-		color_fprintf(s->fp, header_color, _("Initial commit on "));
+		color_fprintf(s->fp, header_color, LABEL(N_("Initial commit on ")));
 
 	if (!strcmp(s->branch, "HEAD")) {
 		color_fprintf(s->fp, color(WT_STATUS_NOBRANCH, s), "%s",
-			      _("HEAD (no branch)"));
+			      LABEL(N_("HEAD (no branch)")));
 		goto conclude;
 	}
 
@@ -1760,8 +1762,6 @@
 	if (!upstream_is_gone && !num_ours && !num_theirs)
 		goto conclude;
 
-#define LABEL(string) (s->no_gettext ? (string) : _(string))
-
 	color_fprintf(s->fp, header_color, " [");
 	if (upstream_is_gone) {
 		color_fprintf(s->fp, header_color, LABEL(N_("gone")));
diff --git a/xdiff/xemit.c b/xdiff/xemit.c
index 7389ce4..8c88dbd 100644
--- a/xdiff/xemit.c
+++ b/xdiff/xemit.c
@@ -183,16 +183,14 @@
 
 				/*
 				 * We don't need additional context if
-				 * a whole function was added, possibly
-				 * starting with empty lines.
+				 * a whole function was added.
 				 */
-				while (i2 < xe->xdf2.nrec &&
-				       is_empty_rec(&xe->xdf2, i2))
+				while (i2 < xe->xdf2.nrec) {
+					if (match_func_rec(&xe->xdf2, xecfg, i2,
+						dummy, sizeof(dummy)) >= 0)
+						goto post_context_calculation;
 					i2++;
-				if (i2 < xe->xdf2.nrec &&
-				    match_func_rec(&xe->xdf2, xecfg, i2,
-						   dummy, sizeof(dummy)) >= 0)
-					goto post_context_calculation;
+				}
 
 				/*
 				 * Otherwise get more context from the