uuid: source re-organization

Move source to uuid subdirectory.
Add in coderviewability.

R=rsc
CC=borman
http://codereview.appspot.com/4838053
diff --git a/CONTRIBUTORS b/CONTRIBUTORS
new file mode 100644
index 0000000..b382a04
--- /dev/null
+++ b/CONTRIBUTORS
@@ -0,0 +1 @@
+Paul Borman <borman@google.com>
diff --git a/lib/codereview/codereview.cfg b/lib/codereview/codereview.cfg
new file mode 100644
index 0000000..112c1c3
--- /dev/null
+++ b/lib/codereview/codereview.cfg
@@ -0,0 +1 @@
+defaultcc: borman@google.com
diff --git a/lib/codereview/codereview.py b/lib/codereview/codereview.py
new file mode 100644
index 0000000..adaff32
--- /dev/null
+++ b/lib/codereview/codereview.py
@@ -0,0 +1,3291 @@
+# coding=utf-8
+# (The line above is necessary so that I can use 世界 in the
+# *comment* below without Python getting all bent out of shape.)
+
+# Copyright 2007-2009 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#	http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+'''Mercurial interface to codereview.appspot.com.
+
+To configure, set the following options in
+your repository's .hg/hgrc file.
+
+	[extensions]
+	codereview = path/to/codereview.py
+
+	[codereview]
+	server = codereview.appspot.com
+
+The server should be running Rietveld; see http://code.google.com/p/rietveld/.
+
+In addition to the new commands, this extension introduces
+the file pattern syntax @nnnnnn, where nnnnnn is a change list
+number, to mean the files included in that change list, which
+must be associated with the current client.
+
+For example, if change 123456 contains the files x.go and y.go,
+"hg diff @123456" is equivalent to"hg diff x.go y.go".
+'''
+
+from mercurial import cmdutil, commands, hg, util, error, match
+from mercurial.node import nullrev, hex, nullid, short
+import os, re, time
+import stat
+import subprocess
+import threading
+from HTMLParser import HTMLParser
+
+# The standard 'json' package is new in Python 2.6.
+# Before that it was an external package named simplejson.
+try:
+	# Standard location in 2.6 and beyond.
+	import json
+except Exception, e:
+	try:
+		# Conventional name for earlier package.
+		import simplejson as json
+	except:
+		try:
+			# Was also bundled with django, which is commonly installed.
+			from django.utils import simplejson as json
+		except:
+			# We give up.
+			raise e
+
+try:
+	hgversion = util.version()
+except:
+	from mercurial.version import version as v
+	hgversion = v.get_version()
+
+try:
+	from mercurial.discovery import findcommonincoming
+except:
+	def findcommonincoming(repo, remote):
+		return repo.findcommonincoming(remote)
+
+# in Mercurial 1.9 the cmdutil.match and cmdutil.revpair moved to scmutil
+if hgversion >= '1.9':
+    from mercurial import scmutil
+else:
+    scmutil = cmdutil
+
+oldMessage = """
+The code review extension requires Mercurial 1.3 or newer.
+
+To install a new Mercurial,
+
+	sudo easy_install mercurial
+
+works on most systems.
+"""
+
+linuxMessage = """
+You may need to clear your current Mercurial installation by running:
+
+	sudo apt-get remove mercurial mercurial-common
+	sudo rm -rf /etc/mercurial
+"""
+
+if hgversion < '1.3':
+	msg = oldMessage
+	if os.access("/etc/mercurial", 0):
+		msg += linuxMessage
+	raise util.Abort(msg)
+
+def promptyesno(ui, msg):
+	# Arguments to ui.prompt changed between 1.3 and 1.3.1.
+	# Even so, some 1.3.1 distributions seem to have the old prompt!?!?
+	# What a terrible way to maintain software.
+	try:
+		return ui.promptchoice(msg, ["&yes", "&no"], 0) == 0
+	except AttributeError:
+		return ui.prompt(msg, ["&yes", "&no"], "y") != "n"
+
+# To experiment with Mercurial in the python interpreter:
+#    >>> repo = hg.repository(ui.ui(), path = ".")
+
+#######################################################################
+# Normally I would split this into multiple files, but it simplifies
+# import path headaches to keep it all in one file.  Sorry.
+
+import sys
+if __name__ == "__main__":
+	print >>sys.stderr, "This is a Mercurial extension and should not be invoked directly."
+	sys.exit(2)
+
+server = "codereview.appspot.com"
+server_url_base = None
+defaultcc = None
+contributors = {}
+missing_codereview = None
+real_rollback = None
+releaseBranch = None
+
+#######################################################################
+# RE: UNICODE STRING HANDLING
+#
+# Python distinguishes between the str (string of bytes)
+# and unicode (string of code points) types.  Most operations
+# work on either one just fine, but some (like regexp matching)
+# require unicode, and others (like write) require str.
+#
+# As befits the language, Python hides the distinction between
+# unicode and str by converting between them silently, but
+# *only* if all the bytes/code points involved are 7-bit ASCII.
+# This means that if you're not careful, your program works
+# fine on "hello, world" and fails on "hello, 世界".  And of course,
+# the obvious way to be careful - use static types - is unavailable.
+# So the only way is trial and error to find where to put explicit
+# conversions.
+#
+# Because more functions do implicit conversion to str (string of bytes)
+# than do implicit conversion to unicode (string of code points),
+# the convention in this module is to represent all text as str,
+# converting to unicode only when calling a unicode-only function
+# and then converting back to str as soon as possible.
+
+def typecheck(s, t):
+	if type(s) != t:
+		raise util.Abort("type check failed: %s has type %s != %s" % (repr(s), type(s), t))
+
+# If we have to pass unicode instead of str, ustr does that conversion clearly.
+def ustr(s):
+	typecheck(s, str)
+	return s.decode("utf-8")
+
+# Even with those, Mercurial still sometimes turns unicode into str
+# and then tries to use it as ascii.  Change Mercurial's default.
+def set_mercurial_encoding_to_utf8():
+	from mercurial import encoding
+	encoding.encoding = 'utf-8'
+
+set_mercurial_encoding_to_utf8()
+
+# Even with those we still run into problems.
+# I tried to do things by the book but could not convince
+# Mercurial to let me check in a change with UTF-8 in the
+# CL description or author field, no matter how many conversions
+# between str and unicode I inserted and despite changing the
+# default encoding.  I'm tired of this game, so set the default
+# encoding for all of Python to 'utf-8', not 'ascii'.
+def default_to_utf8():
+	import sys
+	reload(sys)  # site.py deleted setdefaultencoding; get it back
+	sys.setdefaultencoding('utf-8')
+
+default_to_utf8()
+
+#######################################################################
+# Change list parsing.
+#
+# Change lists are stored in .hg/codereview/cl.nnnnnn
+# where nnnnnn is the number assigned by the code review server.
+# Most data about a change list is stored on the code review server
+# too: the description, reviewer, and cc list are all stored there.
+# The only thing in the cl.nnnnnn file is the list of relevant files.
+# Also, the existence of the cl.nnnnnn file marks this repository
+# as the one where the change list lives.
+
+emptydiff = """Index: ~rietveld~placeholder~
+===================================================================
+diff --git a/~rietveld~placeholder~ b/~rietveld~placeholder~
+new file mode 100644
+"""
+
+class CL(object):
+	def __init__(self, name):
+		typecheck(name, str)
+		self.name = name
+		self.desc = ''
+		self.files = []
+		self.reviewer = []
+		self.cc = []
+		self.url = ''
+		self.local = False
+		self.web = False
+		self.copied_from = None	# None means current user
+		self.mailed = False
+		self.private = False
+
+	def DiskText(self):
+		cl = self
+		s = ""
+		if cl.copied_from:
+			s += "Author: " + cl.copied_from + "\n\n"
+		if cl.private:
+			s += "Private: " + str(self.private) + "\n"
+		s += "Mailed: " + str(self.mailed) + "\n"
+		s += "Description:\n"
+		s += Indent(cl.desc, "\t")
+		s += "Files:\n"
+		for f in cl.files:
+			s += "\t" + f + "\n"
+		typecheck(s, str)
+		return s
+
+	def EditorText(self):
+		cl = self
+		s = _change_prolog
+		s += "\n"
+		if cl.copied_from:
+			s += "Author: " + cl.copied_from + "\n"
+		if cl.url != '':
+			s += 'URL: ' + cl.url + '	# cannot edit\n\n'
+		if cl.private:
+			s += "Private: True\n"
+		s += "Reviewer: " + JoinComma(cl.reviewer) + "\n"
+		s += "CC: " + JoinComma(cl.cc) + "\n"
+		s += "\n"
+		s += "Description:\n"
+		if cl.desc == '':
+			s += "\t<enter description here>\n"
+		else:
+			s += Indent(cl.desc, "\t")
+		s += "\n"
+		if cl.local or cl.name == "new":
+			s += "Files:\n"
+			for f in cl.files:
+				s += "\t" + f + "\n"
+			s += "\n"
+		typecheck(s, str)
+		return s
+
+	def PendingText(self):
+		cl = self
+		s = cl.name + ":" + "\n"
+		s += Indent(cl.desc, "\t")
+		s += "\n"
+		if cl.copied_from:
+			s += "\tAuthor: " + cl.copied_from + "\n"
+		s += "\tReviewer: " + JoinComma(cl.reviewer) + "\n"
+		s += "\tCC: " + JoinComma(cl.cc) + "\n"
+		s += "\tFiles:\n"
+		for f in cl.files:
+			s += "\t\t" + f + "\n"
+		typecheck(s, str)
+		return s
+
+	def Flush(self, ui, repo):
+		if self.name == "new":
+			self.Upload(ui, repo, gofmt_just_warn=True, creating=True)
+		dir = CodeReviewDir(ui, repo)
+		path = dir + '/cl.' + self.name
+		f = open(path+'!', "w")
+		f.write(self.DiskText())
+		f.close()
+		if sys.platform == "win32" and os.path.isfile(path):
+			os.remove(path)
+		os.rename(path+'!', path)
+		if self.web and not self.copied_from:
+			EditDesc(self.name, desc=self.desc,
+				reviewers=JoinComma(self.reviewer), cc=JoinComma(self.cc),
+				private=self.private)
+
+	def Delete(self, ui, repo):
+		dir = CodeReviewDir(ui, repo)
+		os.unlink(dir + "/cl." + self.name)
+
+	def Subject(self):
+		s = line1(self.desc)
+		if len(s) > 60:
+			s = s[0:55] + "..."
+		if self.name != "new":
+			s = "code review %s: %s" % (self.name, s)
+		typecheck(s, str)
+		return s
+
+	def Upload(self, ui, repo, send_mail=False, gofmt=True, gofmt_just_warn=False, creating=False, quiet=False):
+		if not self.files and not creating:
+			ui.warn("no files in change list\n")
+		if ui.configbool("codereview", "force_gofmt", True) and gofmt:
+			CheckFormat(ui, repo, self.files, just_warn=gofmt_just_warn)
+		set_status("uploading CL metadata + diffs")
+		os.chdir(repo.root)
+		form_fields = [
+			("content_upload", "1"),
+			("reviewers", JoinComma(self.reviewer)),
+			("cc", JoinComma(self.cc)),
+			("description", self.desc),
+			("base_hashes", ""),
+		]
+
+		if self.name != "new":
+			form_fields.append(("issue", self.name))
+		vcs = None
+		# We do not include files when creating the issue,
+		# because we want the patch sets to record the repository
+		# and base revision they are diffs against.  We use the patch
+		# set message for that purpose, but there is no message with
+		# the first patch set.  Instead the message gets used as the
+		# new CL's overall subject.  So omit the diffs when creating
+		# and then we'll run an immediate upload.
+		# This has the effect that every CL begins with an empty "Patch set 1".
+		if self.files and not creating:
+			vcs = MercurialVCS(upload_options, ui, repo)
+			data = vcs.GenerateDiff(self.files)
+			files = vcs.GetBaseFiles(data)
+			if len(data) > MAX_UPLOAD_SIZE:
+				uploaded_diff_file = []
+				form_fields.append(("separate_patches", "1"))
+			else:
+				uploaded_diff_file = [("data", "data.diff", data)]
+		else:
+			uploaded_diff_file = [("data", "data.diff", emptydiff)]
+		
+		if vcs and self.name != "new":
+			form_fields.append(("subject", "diff -r " + vcs.base_rev + " " + getremote(ui, repo, {}).path))
+		else:
+			# First upload sets the subject for the CL itself.
+			form_fields.append(("subject", self.Subject()))
+		ctype, body = EncodeMultipartFormData(form_fields, uploaded_diff_file)
+		response_body = MySend("/upload", body, content_type=ctype)
+		patchset = None
+		msg = response_body
+		lines = msg.splitlines()
+		if len(lines) >= 2:
+			msg = lines[0]
+			patchset = lines[1].strip()
+			patches = [x.split(" ", 1) for x in lines[2:]]
+		if response_body.startswith("Issue updated.") and quiet:
+			pass
+		else:
+			ui.status(msg + "\n")
+		set_status("uploaded CL metadata + diffs")
+		if not response_body.startswith("Issue created.") and not response_body.startswith("Issue updated."):
+			raise util.Abort("failed to update issue: " + response_body)
+		issue = msg[msg.rfind("/")+1:]
+		self.name = issue
+		if not self.url:
+			self.url = server_url_base + self.name
+		if not uploaded_diff_file:
+			set_status("uploading patches")
+			patches = UploadSeparatePatches(issue, rpc, patchset, data, upload_options)
+		if vcs:
+			set_status("uploading base files")
+			vcs.UploadBaseFiles(issue, rpc, patches, patchset, upload_options, files)
+		if send_mail:
+			set_status("sending mail")
+			MySend("/" + issue + "/mail", payload="")
+		self.web = True
+		set_status("flushing changes to disk")
+		self.Flush(ui, repo)
+		return
+
+	def Mail(self, ui, repo):
+		pmsg = "Hello " + JoinComma(self.reviewer)
+		if self.cc:
+			pmsg += " (cc: %s)" % (', '.join(self.cc),)
+		pmsg += ",\n"
+		pmsg += "\n"
+		repourl = getremote(ui, repo, {}).path
+		if not self.mailed:
+			pmsg += "I'd like you to review this change to\n" + repourl + "\n"
+		else:
+			pmsg += "Please take another look.\n"
+		typecheck(pmsg, str)
+		PostMessage(ui, self.name, pmsg, subject=self.Subject())
+		self.mailed = True
+		self.Flush(ui, repo)
+
+def GoodCLName(name):
+	typecheck(name, str)
+	return re.match("^[0-9]+$", name)
+
+def ParseCL(text, name):
+	typecheck(text, str)
+	typecheck(name, str)
+	sname = None
+	lineno = 0
+	sections = {
+		'Author': '',
+		'Description': '',
+		'Files': '',
+		'URL': '',
+		'Reviewer': '',
+		'CC': '',
+		'Mailed': '',
+		'Private': '',
+	}
+	for line in text.split('\n'):
+		lineno += 1
+		line = line.rstrip()
+		if line != '' and line[0] == '#':
+			continue
+		if line == '' or line[0] == ' ' or line[0] == '\t':
+			if sname == None and line != '':
+				return None, lineno, 'text outside section'
+			if sname != None:
+				sections[sname] += line + '\n'
+			continue
+		p = line.find(':')
+		if p >= 0:
+			s, val = line[:p].strip(), line[p+1:].strip()
+			if s in sections:
+				sname = s
+				if val != '':
+					sections[sname] += val + '\n'
+				continue
+		return None, lineno, 'malformed section header'
+
+	for k in sections:
+		sections[k] = StripCommon(sections[k]).rstrip()
+
+	cl = CL(name)
+	if sections['Author']:
+		cl.copied_from = sections['Author']
+	cl.desc = sections['Description']
+	for line in sections['Files'].split('\n'):
+		i = line.find('#')
+		if i >= 0:
+			line = line[0:i].rstrip()
+		line = line.strip()
+		if line == '':
+			continue
+		cl.files.append(line)
+	cl.reviewer = SplitCommaSpace(sections['Reviewer'])
+	cl.cc = SplitCommaSpace(sections['CC'])
+	cl.url = sections['URL']
+	if sections['Mailed'] != 'False':
+		# Odd default, but avoids spurious mailings when
+		# reading old CLs that do not have a Mailed: line.
+		# CLs created with this update will always have 
+		# Mailed: False on disk.
+		cl.mailed = True
+	if sections['Private'] in ('True', 'true', 'Yes', 'yes'):
+		cl.private = True
+	if cl.desc == '<enter description here>':
+		cl.desc = ''
+	return cl, 0, ''
+
+def SplitCommaSpace(s):
+	typecheck(s, str)
+	s = s.strip()
+	if s == "":
+		return []
+	return re.split(", *", s)
+
+def CutDomain(s):
+	typecheck(s, str)
+	i = s.find('@')
+	if i >= 0:
+		s = s[0:i]
+	return s
+
+def JoinComma(l):
+	for s in l:
+		typecheck(s, str)
+	return ", ".join(l)
+
+def ExceptionDetail():
+	s = str(sys.exc_info()[0])
+	if s.startswith("<type '") and s.endswith("'>"):
+		s = s[7:-2]
+	elif s.startswith("<class '") and s.endswith("'>"):
+		s = s[8:-2]
+	arg = str(sys.exc_info()[1])
+	if len(arg) > 0:
+		s += ": " + arg
+	return s
+
+def IsLocalCL(ui, repo, name):
+	return GoodCLName(name) and os.access(CodeReviewDir(ui, repo) + "/cl." + name, 0)
+
+# Load CL from disk and/or the web.
+def LoadCL(ui, repo, name, web=True):
+	typecheck(name, str)
+	set_status("loading CL " + name)
+	if not GoodCLName(name):
+		return None, "invalid CL name"
+	dir = CodeReviewDir(ui, repo)
+	path = dir + "cl." + name
+	if os.access(path, 0):
+		ff = open(path)
+		text = ff.read()
+		ff.close()
+		cl, lineno, err = ParseCL(text, name)
+		if err != "":
+			return None, "malformed CL data: "+err
+		cl.local = True
+	else:
+		cl = CL(name)
+	if web:
+		set_status("getting issue metadata from web")
+		d = JSONGet(ui, "/api/" + name + "?messages=true")
+		set_status(None)
+		if d is None:
+			return None, "cannot load CL %s from server" % (name,)
+		if 'owner_email' not in d or 'issue' not in d or str(d['issue']) != name:
+			return None, "malformed response loading CL data from code review server"
+		cl.dict = d
+		cl.reviewer = d.get('reviewers', [])
+		cl.cc = d.get('cc', [])
+		if cl.local and cl.copied_from and cl.desc:
+			# local copy of CL written by someone else
+			# and we saved a description.  use that one,
+			# so that committers can edit the description
+			# before doing hg submit.
+			pass
+		else:
+			cl.desc = d.get('description', "")
+		cl.url = server_url_base + name
+		cl.web = True
+		cl.private = d.get('private', False) != False
+	set_status("loaded CL " + name)
+	return cl, ''
+
+global_status = None
+
+def set_status(s):
+	# print >>sys.stderr, "\t", time.asctime(), s
+	global global_status
+	global_status = s
+
+class StatusThread(threading.Thread):
+	def __init__(self):
+		threading.Thread.__init__(self)
+	def run(self):
+		# pause a reasonable amount of time before
+		# starting to display status messages, so that
+		# most hg commands won't ever see them.
+		time.sleep(30)
+
+		# now show status every 15 seconds
+		while True:
+			time.sleep(15 - time.time() % 15)
+			s = global_status
+			if s is None:
+				continue
+			if s == "":
+				s = "(unknown status)"
+			print >>sys.stderr, time.asctime(), s
+
+def start_status_thread():
+	t = StatusThread()
+	t.setDaemon(True)  # allowed to exit if t is still running
+	t.start()
+
+class LoadCLThread(threading.Thread):
+	def __init__(self, ui, repo, dir, f, web):
+		threading.Thread.__init__(self)
+		self.ui = ui
+		self.repo = repo
+		self.dir = dir
+		self.f = f
+		self.web = web
+		self.cl = None
+	def run(self):
+		cl, err = LoadCL(self.ui, self.repo, self.f[3:], web=self.web)
+		if err != '':
+			self.ui.warn("loading "+self.dir+self.f+": " + err + "\n")
+			return
+		self.cl = cl
+
+# Load all the CLs from this repository.
+def LoadAllCL(ui, repo, web=True):
+	dir = CodeReviewDir(ui, repo)
+	m = {}
+	files = [f for f in os.listdir(dir) if f.startswith('cl.')]
+	if not files:
+		return m
+	active = []
+	first = True
+	for f in files:
+		t = LoadCLThread(ui, repo, dir, f, web)
+		t.start()
+		if web and first:
+			# first request: wait in case it needs to authenticate
+			# otherwise we get lots of user/password prompts
+			# running in parallel.
+			t.join()
+			if t.cl:
+				m[t.cl.name] = t.cl
+			first = False
+		else:
+			active.append(t)
+	for t in active:
+		t.join()
+		if t.cl:
+			m[t.cl.name] = t.cl
+	return m
+
+# Find repository root.  On error, ui.warn and return None
+def RepoDir(ui, repo):
+	url = repo.url();
+	if not url.startswith('file:'):
+		ui.warn("repository %s is not in local file system\n" % (url,))
+		return None
+	url = url[5:]
+	if url.endswith('/'):
+		url = url[:-1]
+	typecheck(url, str)
+	return url
+
+# Find (or make) code review directory.  On error, ui.warn and return None
+def CodeReviewDir(ui, repo):
+	dir = RepoDir(ui, repo)
+	if dir == None:
+		return None
+	dir += '/.hg/codereview/'
+	if not os.path.isdir(dir):
+		try:
+			os.mkdir(dir, 0700)
+		except:
+			ui.warn('cannot mkdir %s: %s\n' % (dir, ExceptionDetail()))
+			return None
+	typecheck(dir, str)
+	return dir
+
+# Turn leading tabs into spaces, so that the common white space
+# prefix doesn't get confused when people's editors write out 
+# some lines with spaces, some with tabs.  Only a heuristic
+# (some editors don't use 8 spaces either) but a useful one.
+def TabsToSpaces(line):
+	i = 0
+	while i < len(line) and line[i] == '\t':
+		i += 1
+	return ' '*(8*i) + line[i:]
+
+# Strip maximal common leading white space prefix from text
+def StripCommon(text):
+	typecheck(text, str)
+	ws = None
+	for line in text.split('\n'):
+		line = line.rstrip()
+		if line == '':
+			continue
+		line = TabsToSpaces(line)
+		white = line[:len(line)-len(line.lstrip())]
+		if ws == None:
+			ws = white
+		else:
+			common = ''
+			for i in range(min(len(white), len(ws))+1):
+				if white[0:i] == ws[0:i]:
+					common = white[0:i]
+			ws = common
+		if ws == '':
+			break
+	if ws == None:
+		return text
+	t = ''
+	for line in text.split('\n'):
+		line = line.rstrip()
+		line = TabsToSpaces(line)
+		if line.startswith(ws):
+			line = line[len(ws):]
+		if line == '' and t == '':
+			continue
+		t += line + '\n'
+	while len(t) >= 2 and t[-2:] == '\n\n':
+		t = t[:-1]
+	typecheck(t, str)
+	return t
+
+# Indent text with indent.
+def Indent(text, indent):
+	typecheck(text, str)
+	typecheck(indent, str)
+	t = ''
+	for line in text.split('\n'):
+		t += indent + line + '\n'
+	typecheck(t, str)
+	return t
+
+# Return the first line of l
+def line1(text):
+	typecheck(text, str)
+	return text.split('\n')[0]
+
+_change_prolog = """# Change list.
+# Lines beginning with # are ignored.
+# Multi-line values should be indented.
+"""
+
+#######################################################################
+# Mercurial helper functions
+
+# Get effective change nodes taking into account applied MQ patches
+def effective_revpair(repo):
+    try:
+	return scmutil.revpair(repo, ['qparent'])
+    except:
+	return scmutil.revpair(repo, None)
+
+# Return list of changed files in repository that match pats.
+# Warn about patterns that did not match.
+def matchpats(ui, repo, pats, opts):
+	matcher = scmutil.match(repo, pats, opts)
+	node1, node2 = effective_revpair(repo)
+	modified, added, removed, deleted, unknown, ignored, clean = repo.status(node1, node2, matcher, ignored=True, clean=True, unknown=True)
+	return (modified, added, removed, deleted, unknown, ignored, clean)
+
+# Return list of changed files in repository that match pats.
+# The patterns came from the command line, so we warn
+# if they have no effect or cannot be understood.
+def ChangedFiles(ui, repo, pats, opts, taken=None):
+	taken = taken or {}
+	# Run each pattern separately so that we can warn about
+	# patterns that didn't do anything useful.
+	for p in pats:
+		modified, added, removed, deleted, unknown, ignored, clean = matchpats(ui, repo, [p], opts)
+		redo = False
+		for f in unknown:
+			promptadd(ui, repo, f)
+			redo = True
+		for f in deleted:
+			promptremove(ui, repo, f)
+			redo = True
+		if redo:
+			modified, added, removed, deleted, unknown, ignored, clean = matchpats(ui, repo, [p], opts)
+		for f in modified + added + removed:
+			if f in taken:
+				ui.warn("warning: %s already in CL %s\n" % (f, taken[f].name))
+		if not modified and not added and not removed:
+			ui.warn("warning: %s did not match any modified files\n" % (p,))
+
+	# Again, all at once (eliminates duplicates)
+	modified, added, removed = matchpats(ui, repo, pats, opts)[:3]
+	l = modified + added + removed
+	l.sort()
+	if taken:
+		l = Sub(l, taken.keys())
+	return l
+
+# Return list of changed files in repository that match pats and still exist.
+def ChangedExistingFiles(ui, repo, pats, opts):
+	modified, added = matchpats(ui, repo, pats, opts)[:2]
+	l = modified + added
+	l.sort()
+	return l
+
+# Return list of files claimed by existing CLs
+def Taken(ui, repo):
+	all = LoadAllCL(ui, repo, web=False)
+	taken = {}
+	for _, cl in all.items():
+		for f in cl.files:
+			taken[f] = cl
+	return taken
+
+# Return list of changed files that are not claimed by other CLs
+def DefaultFiles(ui, repo, pats, opts):
+	return ChangedFiles(ui, repo, pats, opts, taken=Taken(ui, repo))
+
+def Sub(l1, l2):
+	return [l for l in l1 if l not in l2]
+
+def Add(l1, l2):
+	l = l1 + Sub(l2, l1)
+	l.sort()
+	return l
+
+def Intersect(l1, l2):
+	return [l for l in l1 if l in l2]
+
+def getremote(ui, repo, opts):
+	# save $http_proxy; creating the HTTP repo object will
+	# delete it in an attempt to "help"
+	proxy = os.environ.get('http_proxy')
+	source = hg.parseurl(ui.expandpath("default"), None)[0]
+	try:
+		remoteui = hg.remoteui # hg 1.6
+	except:
+		remoteui = cmdutil.remoteui
+	other = hg.repository(remoteui(repo, opts), source)
+	if proxy is not None:
+		os.environ['http_proxy'] = proxy
+	return other
+
+def Incoming(ui, repo, opts):
+	_, incoming, _ = findcommonincoming(repo, getremote(ui, repo, opts))
+	return incoming
+
+desc_re = '^(.+: |(tag )?(release|weekly)\.|fix build|undo CL)'
+
+desc_msg = '''Your CL description appears not to use the standard form.
+
+The first line of your change description is conventionally a
+one-line summary of the change, prefixed by the primary affected package,
+and is used as the subject for code review mail; the rest of the description
+elaborates.
+
+Examples:
+
+	encoding/rot13: new package
+
+	math: add IsInf, IsNaN
+	
+	net: fix cname in LookupHost
+
+	unicode: update to Unicode 5.0.2
+
+'''
+
+
+def promptremove(ui, repo, f):
+	if promptyesno(ui, "hg remove %s (y/n)?" % (f,)):
+		if commands.remove(ui, repo, 'path:'+f) != 0:
+			ui.warn("error removing %s" % (f,))
+
+def promptadd(ui, repo, f):
+	if promptyesno(ui, "hg add %s (y/n)?" % (f,)):
+		if commands.add(ui, repo, 'path:'+f) != 0:
+			ui.warn("error adding %s" % (f,))
+
+def EditCL(ui, repo, cl):
+	set_status(None)	# do not show status
+	s = cl.EditorText()
+	while True:
+		s = ui.edit(s, ui.username())
+		clx, line, err = ParseCL(s, cl.name)
+		if err != '':
+			if not promptyesno(ui, "error parsing change list: line %d: %s\nre-edit (y/n)?" % (line, err)):
+				return "change list not modified"
+			continue
+		
+		# Check description.
+		if clx.desc == '':
+			if promptyesno(ui, "change list should have a description\nre-edit (y/n)?"):
+				continue
+		elif re.search('<enter reason for undo>', clx.desc):
+			if promptyesno(ui, "change list description omits reason for undo\nre-edit (y/n)?"):
+				continue
+		elif not re.match(desc_re, clx.desc.split('\n')[0]):
+			if promptyesno(ui, desc_msg + "re-edit (y/n)?"):
+				continue
+
+		# Check file list for files that need to be hg added or hg removed
+		# or simply aren't understood.
+		pats = ['path:'+f for f in clx.files]
+		modified, added, removed, deleted, unknown, ignored, clean = matchpats(ui, repo, pats, {})
+		files = []
+		for f in clx.files:
+			if f in modified or f in added or f in removed:
+				files.append(f)
+				continue
+			if f in deleted:
+				promptremove(ui, repo, f)
+				files.append(f)
+				continue
+			if f in unknown:
+				promptadd(ui, repo, f)
+				files.append(f)
+				continue
+			if f in ignored:
+				ui.warn("error: %s is excluded by .hgignore; omitting\n" % (f,))
+				continue
+			if f in clean:
+				ui.warn("warning: %s is listed in the CL but unchanged\n" % (f,))
+				files.append(f)
+				continue
+			p = repo.root + '/' + f
+			if os.path.isfile(p):
+				ui.warn("warning: %s is a file but not known to hg\n" % (f,))
+				files.append(f)
+				continue
+			if os.path.isdir(p):
+				ui.warn("error: %s is a directory, not a file; omitting\n" % (f,))
+				continue
+			ui.warn("error: %s does not exist; omitting\n" % (f,))
+		clx.files = files
+
+		cl.desc = clx.desc
+		cl.reviewer = clx.reviewer
+		cl.cc = clx.cc
+		cl.files = clx.files
+		cl.private = clx.private
+		break
+	return ""
+
+# For use by submit, etc. (NOT by change)
+# Get change list number or list of files from command line.
+# If files are given, make a new change list.
+def CommandLineCL(ui, repo, pats, opts, defaultcc=None):
+	if len(pats) > 0 and GoodCLName(pats[0]):
+		if len(pats) != 1:
+			return None, "cannot specify change number and file names"
+		if opts.get('message'):
+			return None, "cannot use -m with existing CL"
+		cl, err = LoadCL(ui, repo, pats[0], web=True)
+		if err != "":
+			return None, err
+	else:
+		cl = CL("new")
+		cl.local = True
+		cl.files = ChangedFiles(ui, repo, pats, opts, taken=Taken(ui, repo))
+		if not cl.files:
+			return None, "no files changed"
+	if opts.get('reviewer'):
+		cl.reviewer = Add(cl.reviewer, SplitCommaSpace(opts.get('reviewer')))
+	if opts.get('cc'):
+		cl.cc = Add(cl.cc, SplitCommaSpace(opts.get('cc')))
+	if defaultcc:
+		cl.cc = Add(cl.cc, defaultcc)
+	if cl.name == "new":
+		if opts.get('message'):
+			cl.desc = opts.get('message')
+		else:
+			err = EditCL(ui, repo, cl)
+			if err != '':
+				return None, err
+	return cl, ""
+
+# reposetup replaces cmdutil.match with this wrapper,
+# which expands the syntax @clnumber to mean the files
+# in that CL.
+original_match = None
+def ReplacementForCmdutilMatch(repo, pats=None, opts=None, globbed=False, default='relpath'):
+	taken = []
+	files = []
+	pats = pats or []
+	opts = opts or {}
+	for p in pats:
+		if p.startswith('@'):
+			taken.append(p)
+			clname = p[1:]
+			if not GoodCLName(clname):
+				raise util.Abort("invalid CL name " + clname)
+			cl, err = LoadCL(repo.ui, repo, clname, web=False)
+			if err != '':
+				raise util.Abort("loading CL " + clname + ": " + err)
+			if not cl.files:
+				raise util.Abort("no files in CL " + clname)
+			files = Add(files, cl.files)
+	pats = Sub(pats, taken) + ['path:'+f for f in files]
+
+	# work-around for http://selenic.com/hg/rev/785bbc8634f8
+	if hgversion >= '1.9' and not hasattr(repo, 'match'):
+		repo = repo[None]
+
+	return original_match(repo, pats=pats, opts=opts, globbed=globbed, default=default)
+
+def RelativePath(path, cwd):
+	n = len(cwd)
+	if path.startswith(cwd) and path[n] == '/':
+		return path[n+1:]
+	return path
+
+def CheckFormat(ui, repo, files, just_warn=False):
+	set_status("running gofmt")
+	CheckGofmt(ui, repo, files, just_warn)
+	CheckTabfmt(ui, repo, files, just_warn)
+
+# Check that gofmt run on the list of files does not change them
+def CheckGofmt(ui, repo, files, just_warn):
+	files = [f for f in files if (f.startswith('src/') or f.startswith('test/bench/')) and f.endswith('.go')]
+	if not files:
+		return
+	cwd = os.getcwd()
+	files = [RelativePath(repo.root + '/' + f, cwd) for f in files]
+	files = [f for f in files if os.access(f, 0)]
+	if not files:
+		return
+	try:
+		cmd = subprocess.Popen(["gofmt", "-l"] + files, shell=False, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, close_fds=sys.platform != "win32")
+		cmd.stdin.close()
+	except:
+		raise util.Abort("gofmt: " + ExceptionDetail())
+	data = cmd.stdout.read()
+	errors = cmd.stderr.read()
+	cmd.wait()
+	set_status("done with gofmt")
+	if len(errors) > 0:
+		ui.warn("gofmt errors:\n" + errors.rstrip() + "\n")
+		return
+	if len(data) > 0:
+		msg = "gofmt needs to format these files (run hg gofmt):\n" + Indent(data, "\t").rstrip()
+		if just_warn:
+			ui.warn("warning: " + msg + "\n")
+		else:
+			raise util.Abort(msg)
+	return
+
+# Check that *.[chys] files indent using tabs.
+def CheckTabfmt(ui, repo, files, just_warn):
+	files = [f for f in files if f.startswith('src/') and re.search(r"\.[chys]$", f)]
+	if not files:
+		return
+	cwd = os.getcwd()
+	files = [RelativePath(repo.root + '/' + f, cwd) for f in files]
+	files = [f for f in files if os.access(f, 0)]
+	badfiles = []
+	for f in files:
+		try:
+			for line in open(f, 'r'):
+				# Four leading spaces is enough to complain about,
+				# except that some Plan 9 code uses four spaces as the label indent,
+				# so allow that.
+				if line.startswith('    ') and not re.match('    [A-Za-z0-9_]+:', line):
+					badfiles.append(f)
+					break
+		except:
+			# ignore cannot open file, etc.
+			pass
+	if len(badfiles) > 0:
+		msg = "these files use spaces for indentation (use tabs instead):\n\t" + "\n\t".join(badfiles)
+		if just_warn:
+			ui.warn("warning: " + msg + "\n")
+		else:
+			raise util.Abort(msg)
+	return
+
+#######################################################################
+# Mercurial commands
+
+# every command must take a ui and and repo as arguments.
+# opts is a dict where you can find other command line flags
+#
+# Other parameters are taken in order from items on the command line that
+# don't start with a dash.  If no default value is given in the parameter list,
+# they are required.
+#
+
+def change(ui, repo, *pats, **opts):
+	"""create, edit or delete a change list
+
+	Create, edit or delete a change list.
+	A change list is a group of files to be reviewed and submitted together,
+	plus a textual description of the change.
+	Change lists are referred to by simple alphanumeric names.
+
+	Changes must be reviewed before they can be submitted.
+
+	In the absence of options, the change command opens the
+	change list for editing in the default editor.
+
+	Deleting a change with the -d or -D flag does not affect
+	the contents of the files listed in that change.  To revert
+	the files listed in a change, use
+
+		hg revert @123456
+
+	before running hg change -d 123456.
+	"""
+
+	if missing_codereview:
+		return missing_codereview
+	
+	dirty = {}
+	if len(pats) > 0 and GoodCLName(pats[0]):
+		name = pats[0]
+		if len(pats) != 1:
+			return "cannot specify CL name and file patterns"
+		pats = pats[1:]
+		cl, err = LoadCL(ui, repo, name, web=True)
+		if err != '':
+			return err
+		if not cl.local and (opts["stdin"] or not opts["stdout"]):
+			return "cannot change non-local CL " + name
+	else:
+		if repo[None].branch() != "default":
+			return "cannot run hg change outside default branch"
+		name = "new"
+		cl = CL("new")
+		dirty[cl] = True
+		files = ChangedFiles(ui, repo, pats, opts, taken=Taken(ui, repo))
+
+	if opts["delete"] or opts["deletelocal"]:
+		if opts["delete"] and opts["deletelocal"]:
+			return "cannot use -d and -D together"
+		flag = "-d"
+		if opts["deletelocal"]:
+			flag = "-D"
+		if name == "new":
+			return "cannot use "+flag+" with file patterns"
+		if opts["stdin"] or opts["stdout"]:
+			return "cannot use "+flag+" with -i or -o"
+		if not cl.local:
+			return "cannot change non-local CL " + name
+		if opts["delete"]:
+			if cl.copied_from:
+				return "original author must delete CL; hg change -D will remove locally"
+			PostMessage(ui, cl.name, "*** Abandoned ***", send_mail=cl.mailed)
+			EditDesc(cl.name, closed=True, private=cl.private)
+		cl.Delete(ui, repo)
+		return
+
+	if opts["stdin"]:
+		s = sys.stdin.read()
+		clx, line, err = ParseCL(s, name)
+		if err != '':
+			return "error parsing change list: line %d: %s" % (line, err)
+		if clx.desc is not None:
+			cl.desc = clx.desc;
+			dirty[cl] = True
+		if clx.reviewer is not None:
+			cl.reviewer = clx.reviewer
+			dirty[cl] = True
+		if clx.cc is not None:
+			cl.cc = clx.cc
+			dirty[cl] = True
+		if clx.files is not None:
+			cl.files = clx.files
+			dirty[cl] = True
+		if clx.private != cl.private:
+			cl.private = clx.private
+			dirty[cl] = True
+
+	if not opts["stdin"] and not opts["stdout"]:
+		if name == "new":
+			cl.files = files
+		err = EditCL(ui, repo, cl)
+		if err != "":
+			return err
+		dirty[cl] = True
+
+	for d, _ in dirty.items():
+		name = d.name
+		d.Flush(ui, repo)
+		if name == "new":
+			d.Upload(ui, repo, quiet=True)
+
+	if opts["stdout"]:
+		ui.write(cl.EditorText())
+	elif opts["pending"]:
+		ui.write(cl.PendingText())
+	elif name == "new":
+		if ui.quiet:
+			ui.write(cl.name)
+		else:
+			ui.write("CL created: " + cl.url + "\n")
+	return
+
+def code_login(ui, repo, **opts):
+	"""log in to code review server
+
+	Logs in to the code review server, saving a cookie in
+	a file in your home directory.
+	"""
+	if missing_codereview:
+		return missing_codereview
+
+	MySend(None)
+
+def clpatch(ui, repo, clname, **opts):
+	"""import a patch from the code review server
+
+	Imports a patch from the code review server into the local client.
+	If the local client has already modified any of the files that the
+	patch modifies, this command will refuse to apply the patch.
+
+	Submitting an imported patch will keep the original author's
+	name as the Author: line but add your own name to a Committer: line.
+	"""
+	if repo[None].branch() != "default":
+		return "cannot run hg clpatch outside default branch"
+	return clpatch_or_undo(ui, repo, clname, opts, mode="clpatch")
+
+def undo(ui, repo, clname, **opts):
+	"""undo the effect of a CL
+	
+	Creates a new CL that undoes an earlier CL.
+	After creating the CL, opens the CL text for editing so that
+	you can add the reason for the undo to the description.
+	"""
+	if repo[None].branch() != "default":
+		return "cannot run hg undo outside default branch"
+	return clpatch_or_undo(ui, repo, clname, opts, mode="undo")
+
+def release_apply(ui, repo, clname, **opts):
+	"""apply a CL to the release branch
+
+	Creates a new CL copying a previously committed change
+	from the main branch to the release branch.
+	The current client must either be clean or already be in
+	the release branch.
+	
+	The release branch must be created by starting with a
+	clean client, disabling the code review plugin, and running:
+	
+		hg update weekly.YYYY-MM-DD
+		hg branch release-branch.rNN
+		hg commit -m 'create release-branch.rNN'
+		hg push --new-branch
+	
+	Then re-enable the code review plugin.
+	
+	People can test the release branch by running
+	
+		hg update release-branch.rNN
+	
+	in a clean client.  To return to the normal tree,
+	
+		hg update default
+	
+	Move changes since the weekly into the release branch 
+	using hg release-apply followed by the usual code review
+	process and hg submit.
+
+	When it comes time to tag the release, record the
+	final long-form tag of the release-branch.rNN
+	in the *default* branch's .hgtags file.  That is, run
+	
+		hg update default
+	
+	and then edit .hgtags as you would for a weekly.
+		
+	"""
+	c = repo[None]
+	if not releaseBranch:
+		return "no active release branches"
+	if c.branch() != releaseBranch:
+		if c.modified() or c.added() or c.removed():
+			raise util.Abort("uncommitted local changes - cannot switch branches")
+		err = hg.clean(repo, releaseBranch)
+		if err:
+			return err
+	try:
+		err = clpatch_or_undo(ui, repo, clname, opts, mode="backport")
+		if err:
+			raise util.Abort(err)
+	except Exception, e:
+		hg.clean(repo, "default")
+		raise e
+	return None
+
+def rev2clname(rev):
+	# Extract CL name from revision description.
+	# The last line in the description that is a codereview URL is the real one.
+	# Earlier lines might be part of the user-written description.
+	all = re.findall('(?m)^http://codereview.appspot.com/([0-9]+)$', rev.description())
+	if len(all) > 0:
+		return all[-1]
+	return ""
+
+undoHeader = """undo CL %s / %s
+
+<enter reason for undo>
+
+««« original CL description
+"""
+
+undoFooter = """
+»»»
+"""
+
+backportHeader = """[%s] %s
+
+««« CL %s / %s
+"""
+
+backportFooter = """
+»»»
+"""
+
+# Implementation of clpatch/undo.
+def clpatch_or_undo(ui, repo, clname, opts, mode):
+	if missing_codereview:
+		return missing_codereview
+
+	if mode == "undo" or mode == "backport":
+		if hgversion < '1.4':
+			# Don't have cmdutil.match (see implementation of sync command).
+			return "hg is too old to run hg %s - update to 1.4 or newer" % mode
+
+		# Find revision in Mercurial repository.
+		# Assume CL number is 7+ decimal digits.
+		# Otherwise is either change log sequence number (fewer decimal digits),
+		# hexadecimal hash, or tag name.
+		# Mercurial will fall over long before the change log
+		# sequence numbers get to be 7 digits long.
+		if re.match('^[0-9]{7,}$', clname):
+			found = False
+			matchfn = scmutil.match(repo, [], {'rev': None})
+			def prep(ctx, fns):
+				pass
+			for ctx in cmdutil.walkchangerevs(repo, matchfn, {'rev': None}, prep):
+				rev = repo[ctx.rev()]
+				# Last line with a code review URL is the actual review URL.
+				# Earlier ones might be part of the CL description.
+				n = rev2clname(rev)
+				if n == clname:
+					found = True
+					break
+			if not found:
+				return "cannot find CL %s in local repository" % clname
+		else:
+			rev = repo[clname]
+			if not rev:
+				return "unknown revision %s" % clname
+			clname = rev2clname(rev)
+			if clname == "":
+				return "cannot find CL name in revision description"
+		
+		# Create fresh CL and start with patch that would reverse the change.
+		vers = short(rev.node())
+		cl = CL("new")
+		desc = str(rev.description())
+		if mode == "undo":
+			cl.desc = (undoHeader % (clname, vers)) + desc + undoFooter
+		else:
+			cl.desc = (backportHeader % (releaseBranch, line1(desc), clname, vers)) + desc + undoFooter
+		v1 = vers
+		v0 = short(rev.parents()[0].node())
+		if mode == "undo":
+			arg = v1 + ":" + v0
+		else:
+			vers = v0
+			arg = v0 + ":" + v1
+		patch = RunShell(["hg", "diff", "--git", "-r", arg])
+
+	else:  # clpatch
+		cl, vers, patch, err = DownloadCL(ui, repo, clname)
+		if err != "":
+			return err
+		if patch == emptydiff:
+			return "codereview issue %s has no diff" % clname
+
+	# find current hg version (hg identify)
+	ctx = repo[None]
+	parents = ctx.parents()
+	id = '+'.join([short(p.node()) for p in parents])
+
+	# if version does not match the patch version,
+	# try to update the patch line numbers.
+	if vers != "" and id != vers:
+		# "vers in repo" gives the wrong answer
+		# on some versions of Mercurial.  Instead, do the actual
+		# lookup and catch the exception.
+		try:
+			repo[vers].description()
+		except:
+			return "local repository is out of date; sync to get %s" % (vers)
+		patch1, err = portPatch(repo, patch, vers, id)
+		if err != "":
+			if not opts["ignore_hgpatch_failure"]:
+				return "codereview issue %s is out of date: %s (%s->%s)" % (clname, err, vers, id)
+		else:
+			patch = patch1
+	argv = ["hgpatch"]
+	if opts["no_incoming"] or mode == "backport":
+		argv += ["--checksync=false"]
+	try:
+		cmd = subprocess.Popen(argv, shell=False, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=None, close_fds=sys.platform != "win32")
+	except:
+		return "hgpatch: " + ExceptionDetail()
+
+	out, err = cmd.communicate(patch)
+	if cmd.returncode != 0 and not opts["ignore_hgpatch_failure"]:
+		return "hgpatch failed"
+	cl.local = True
+	cl.files = out.strip().split()
+	if not cl.files and not opts["ignore_hgpatch_failure"]:
+		return "codereview issue %s has no changed files" % clname
+	files = ChangedFiles(ui, repo, [], opts)
+	extra = Sub(cl.files, files)
+	if extra:
+		ui.warn("warning: these files were listed in the patch but not changed:\n\t" + "\n\t".join(extra) + "\n")
+	cl.Flush(ui, repo)
+	if mode == "undo":
+		err = EditCL(ui, repo, cl)
+		if err != "":
+			return "CL created, but error editing: " + err
+		cl.Flush(ui, repo)
+	else:
+		ui.write(cl.PendingText() + "\n")
+
+# portPatch rewrites patch from being a patch against
+# oldver to being a patch against newver.
+def portPatch(repo, patch, oldver, newver):
+	lines = patch.splitlines(True) # True = keep \n
+	delta = None
+	for i in range(len(lines)):
+		line = lines[i]
+		if line.startswith('--- a/'):
+			file = line[6:-1]
+			delta = fileDeltas(repo, file, oldver, newver)
+		if not delta or not line.startswith('@@ '):
+			continue
+		# @@ -x,y +z,w @@ means the patch chunk replaces
+		# the original file's line numbers x up to x+y with the
+		# line numbers z up to z+w in the new file.
+		# Find the delta from x in the original to the same
+		# line in the current version and add that delta to both
+		# x and z.
+		m = re.match('@@ -([0-9]+),([0-9]+) \+([0-9]+),([0-9]+) @@', line)
+		if not m:
+			return None, "error parsing patch line numbers"
+		n1, len1, n2, len2 = int(m.group(1)), int(m.group(2)), int(m.group(3)), int(m.group(4))
+		d, err = lineDelta(delta, n1, len1)
+		if err != "":
+			return "", err
+		n1 += d
+		n2 += d
+		lines[i] = "@@ -%d,%d +%d,%d @@\n" % (n1, len1, n2, len2)
+		
+	newpatch = ''.join(lines)
+	return newpatch, ""
+
+# fileDelta returns the line number deltas for the given file's
+# changes from oldver to newver.
+# The deltas are a list of (n, len, newdelta) triples that say
+# lines [n, n+len) were modified, and after that range the
+# line numbers are +newdelta from what they were before.
+def fileDeltas(repo, file, oldver, newver):
+	cmd = ["hg", "diff", "--git", "-r", oldver + ":" + newver, "path:" + file]
+	data = RunShell(cmd, silent_ok=True)
+	deltas = []
+	for line in data.splitlines():
+		m = re.match('@@ -([0-9]+),([0-9]+) \+([0-9]+),([0-9]+) @@', line)
+		if not m:
+			continue
+		n1, len1, n2, len2 = int(m.group(1)), int(m.group(2)), int(m.group(3)), int(m.group(4))
+		deltas.append((n1, len1, n2+len2-(n1+len1)))
+	return deltas
+
+# lineDelta finds the appropriate line number delta to apply to the lines [n, n+len).
+# It returns an error if those lines were rewritten by the patch.
+def lineDelta(deltas, n, len):
+	d = 0
+	for (old, oldlen, newdelta) in deltas:
+		if old >= n+len:
+			break
+		if old+len > n:
+			return 0, "patch and recent changes conflict"
+		d = newdelta
+	return d, ""
+
+def download(ui, repo, clname, **opts):
+	"""download a change from the code review server
+
+	Download prints a description of the given change list
+	followed by its diff, downloaded from the code review server.
+	"""
+	if missing_codereview:
+		return missing_codereview
+
+	cl, vers, patch, err = DownloadCL(ui, repo, clname)
+	if err != "":
+		return err
+	ui.write(cl.EditorText() + "\n")
+	ui.write(patch + "\n")
+	return
+
+def file(ui, repo, clname, pat, *pats, **opts):
+	"""assign files to or remove files from a change list
+
+	Assign files to or (with -d) remove files from a change list.
+
+	The -d option only removes files from the change list.
+	It does not edit them or remove them from the repository.
+	"""
+	if missing_codereview:
+		return missing_codereview
+
+	pats = tuple([pat] + list(pats))
+	if not GoodCLName(clname):
+		return "invalid CL name " + clname
+
+	dirty = {}
+	cl, err = LoadCL(ui, repo, clname, web=False)
+	if err != '':
+		return err
+	if not cl.local:
+		return "cannot change non-local CL " + clname
+
+	files = ChangedFiles(ui, repo, pats, opts)
+
+	if opts["delete"]:
+		oldfiles = Intersect(files, cl.files)
+		if oldfiles:
+			if not ui.quiet:
+				ui.status("# Removing files from CL.  To undo:\n")
+				ui.status("#	cd %s\n" % (repo.root))
+				for f in oldfiles:
+					ui.status("#	hg file %s %s\n" % (cl.name, f))
+			cl.files = Sub(cl.files, oldfiles)
+			cl.Flush(ui, repo)
+		else:
+			ui.status("no such files in CL")
+		return
+
+	if not files:
+		return "no such modified files"
+
+	files = Sub(files, cl.files)
+	taken = Taken(ui, repo)
+	warned = False
+	for f in files:
+		if f in taken:
+			if not warned and not ui.quiet:
+				ui.status("# Taking files from other CLs.  To undo:\n")
+				ui.status("#	cd %s\n" % (repo.root))
+				warned = True
+			ocl = taken[f]
+			if not ui.quiet:
+				ui.status("#	hg file %s %s\n" % (ocl.name, f))
+			if ocl not in dirty:
+				ocl.files = Sub(ocl.files, files)
+				dirty[ocl] = True
+	cl.files = Add(cl.files, files)
+	dirty[cl] = True
+	for d, _ in dirty.items():
+		d.Flush(ui, repo)
+	return
+
+def gofmt(ui, repo, *pats, **opts):
+	"""apply gofmt to modified files
+
+	Applies gofmt to the modified files in the repository that match
+	the given patterns.
+	"""
+	if missing_codereview:
+		return missing_codereview
+
+	files = ChangedExistingFiles(ui, repo, pats, opts)
+	files = [f for f in files if f.endswith(".go")]
+	if not files:
+		return "no modified go files"
+	cwd = os.getcwd()
+	files = [RelativePath(repo.root + '/' + f, cwd) for f in files]
+	try:
+		cmd = ["gofmt", "-l"]
+		if not opts["list"]:
+			cmd += ["-w"]
+		if os.spawnvp(os.P_WAIT, "gofmt", cmd + files) != 0:
+			raise util.Abort("gofmt did not exit cleanly")
+	except error.Abort, e:
+		raise
+	except:
+		raise util.Abort("gofmt: " + ExceptionDetail())
+	return
+
+def mail(ui, repo, *pats, **opts):
+	"""mail a change for review
+
+	Uploads a patch to the code review server and then sends mail
+	to the reviewer and CC list asking for a review.
+	"""
+	if missing_codereview:
+		return missing_codereview
+
+	cl, err = CommandLineCL(ui, repo, pats, opts, defaultcc=defaultcc)
+	if err != "":
+		return err
+	cl.Upload(ui, repo, gofmt_just_warn=True)
+	if not cl.reviewer:
+		# If no reviewer is listed, assign the review to defaultcc.
+		# This makes sure that it appears in the 
+		# codereview.appspot.com/user/defaultcc
+		# page, so that it doesn't get dropped on the floor.
+		if not defaultcc:
+			return "no reviewers listed in CL"
+		cl.cc = Sub(cl.cc, defaultcc)
+		cl.reviewer = defaultcc
+		cl.Flush(ui, repo)
+
+	if cl.files == []:
+		return "no changed files, not sending mail"
+
+	cl.Mail(ui, repo)		
+
+def pending(ui, repo, *pats, **opts):
+	"""show pending changes
+
+	Lists pending changes followed by a list of unassigned but modified files.
+	"""
+	if missing_codereview:
+		return missing_codereview
+
+	m = LoadAllCL(ui, repo, web=True)
+	names = m.keys()
+	names.sort()
+	for name in names:
+		cl = m[name]
+		ui.write(cl.PendingText() + "\n")
+
+	files = DefaultFiles(ui, repo, [], opts)
+	if len(files) > 0:
+		s = "Changed files not in any CL:\n"
+		for f in files:
+			s += "\t" + f + "\n"
+		ui.write(s)
+
+def reposetup(ui, repo):
+	global original_match
+	if original_match is None:
+		start_status_thread()
+		original_match = scmutil.match
+		scmutil.match = ReplacementForCmdutilMatch
+		RietveldSetup(ui, repo)
+
+def CheckContributor(ui, repo, user=None):
+	set_status("checking CONTRIBUTORS file")
+	user, userline = FindContributor(ui, repo, user, warn=False)
+	if not userline:
+		raise util.Abort("cannot find %s in CONTRIBUTORS" % (user,))
+	return userline
+
+def FindContributor(ui, repo, user=None, warn=True):
+	if not user:
+		user = ui.config("ui", "username")
+		if not user:
+			raise util.Abort("[ui] username is not configured in .hgrc")
+	user = user.lower()
+	m = re.match(r".*<(.*)>", user)
+	if m:
+		user = m.group(1)
+
+	if user not in contributors:
+		if warn:
+			ui.warn("warning: cannot find %s in CONTRIBUTORS\n" % (user,))
+		return user, None
+	
+	user, email = contributors[user]
+	return email, "%s <%s>" % (user, email)
+
+def submit(ui, repo, *pats, **opts):
+	"""submit change to remote repository
+
+	Submits change to remote repository.
+	Bails out if the local repository is not in sync with the remote one.
+	"""
+	if missing_codereview:
+		return missing_codereview
+
+	# We already called this on startup but sometimes Mercurial forgets.
+	set_mercurial_encoding_to_utf8()
+
+	repo.ui.quiet = True
+	if not opts["no_incoming"] and Incoming(ui, repo, opts):
+		return "local repository out of date; must sync before submit"
+
+	cl, err = CommandLineCL(ui, repo, pats, opts, defaultcc=defaultcc)
+	if err != "":
+		return err
+
+	user = None
+	if cl.copied_from:
+		user = cl.copied_from
+	userline = CheckContributor(ui, repo, user)
+	typecheck(userline, str)
+
+	about = ""
+	if cl.reviewer:
+		about += "R=" + JoinComma([CutDomain(s) for s in cl.reviewer]) + "\n"
+	if opts.get('tbr'):
+		tbr = SplitCommaSpace(opts.get('tbr'))
+		cl.reviewer = Add(cl.reviewer, tbr)
+		about += "TBR=" + JoinComma([CutDomain(s) for s in tbr]) + "\n"
+	if cl.cc:
+		about += "CC=" + JoinComma([CutDomain(s) for s in cl.cc]) + "\n"
+
+	if not cl.reviewer:
+		return "no reviewers listed in CL"
+
+	if not cl.local:
+		return "cannot submit non-local CL"
+
+	# upload, to sync current patch and also get change number if CL is new.
+	if not cl.copied_from:
+		cl.Upload(ui, repo, gofmt_just_warn=True)
+
+	# check gofmt for real; allowed upload to warn in order to save CL.
+	cl.Flush(ui, repo)
+	CheckFormat(ui, repo, cl.files)
+
+	about += "%s%s\n" % (server_url_base, cl.name)
+
+	if cl.copied_from:
+		about += "\nCommitter: " + CheckContributor(ui, repo, None) + "\n"
+	typecheck(about, str)
+
+	if not cl.mailed and not cl.copied_from:		# in case this is TBR
+		cl.Mail(ui, repo)
+
+	# submit changes locally
+	date = opts.get('date')
+	if date:
+		opts['date'] = util.parsedate(date)
+		typecheck(opts['date'], str)
+	opts['message'] = cl.desc.rstrip() + "\n\n" + about
+	typecheck(opts['message'], str)
+
+	if opts['dryrun']:
+		print "NOT SUBMITTING:"
+		print "User: ", userline
+		print "Message:"
+		print Indent(opts['message'], "\t")
+		print "Files:"
+		print Indent('\n'.join(cl.files), "\t")
+		return "dry run; not submitted"
+
+	m = match.exact(repo.root, repo.getcwd(), cl.files)
+	node = repo.commit(ustr(opts['message']), ustr(userline), opts.get('date'), m)
+	if not node:
+		return "nothing changed"
+
+	# push to remote; if it fails for any reason, roll back
+	try:
+		log = repo.changelog
+		rev = log.rev(node)
+		parents = log.parentrevs(rev)
+		if (rev-1 not in parents and
+				(parents == (nullrev, nullrev) or
+				len(log.heads(log.node(parents[0]))) > 1 and
+				(parents[1] == nullrev or len(log.heads(log.node(parents[1]))) > 1))):
+			# created new head
+			raise util.Abort("local repository out of date; must sync before submit")
+
+		# push changes to remote.
+		# if it works, we're committed.
+		# if not, roll back
+		other = getremote(ui, repo, opts)
+		r = repo.push(other, False, None)
+		if r == 0:
+			raise util.Abort("local repository out of date; must sync before submit")
+	except:
+		real_rollback()
+		raise
+
+	# we're committed. upload final patch, close review, add commit message
+	changeURL = short(node)
+	url = other.url()
+	m = re.match("^https?://([^@/]+@)?([^.]+)\.googlecode\.com/hg/?", url)
+	if m:
+		changeURL = "http://code.google.com/p/%s/source/detail?r=%s" % (m.group(2), changeURL)
+	else:
+		print >>sys.stderr, "URL: ", url
+	pmsg = "*** Submitted as " + changeURL + " ***\n\n" + opts['message']
+
+	# When posting, move reviewers to CC line,
+	# so that the issue stops showing up in their "My Issues" page.
+	PostMessage(ui, cl.name, pmsg, reviewers="", cc=JoinComma(cl.reviewer+cl.cc))
+
+	if not cl.copied_from:
+		EditDesc(cl.name, closed=True, private=cl.private)
+	cl.Delete(ui, repo)
+	
+	c = repo[None]
+	if c.branch() == releaseBranch and not c.modified() and not c.added() and not c.removed():
+		ui.write("switching from %s to default branch.\n" % releaseBranch)
+		err = hg.clean(repo, "default")
+		if err:
+			return err
+	return None
+
+def sync(ui, repo, **opts):
+	"""synchronize with remote repository
+
+	Incorporates recent changes from the remote repository
+	into the local repository.
+	"""
+	if missing_codereview:
+		return missing_codereview
+
+	if not opts["local"]:
+		ui.status = sync_note
+		ui.note = sync_note
+		other = getremote(ui, repo, opts)
+		modheads = repo.pull(other)
+		err = commands.postincoming(ui, repo, modheads, True, "tip")
+		if err:
+			return err
+	commands.update(ui, repo, rev="default")
+	sync_changes(ui, repo)
+
+def sync_note(msg):
+	# we run sync (pull -u) in verbose mode to get the
+	# list of files being updated, but that drags along
+	# a bunch of messages we don't care about.
+	# omit them.
+	if msg == 'resolving manifests\n':
+		return
+	if msg == 'searching for changes\n':
+		return
+	if msg == "couldn't find merge tool hgmerge\n":
+		return
+	sys.stdout.write(msg)
+
+def sync_changes(ui, repo):
+	# Look through recent change log descriptions to find
+	# potential references to http://.*/our-CL-number.
+	# Double-check them by looking at the Rietveld log.
+	def Rev(rev):
+		desc = repo[rev].description().strip()
+		for clname in re.findall('(?m)^http://(?:[^\n]+)/([0-9]+)$', desc):
+			if IsLocalCL(ui, repo, clname) and IsRietveldSubmitted(ui, clname, repo[rev].hex()):
+				ui.warn("CL %s submitted as %s; closing\n" % (clname, repo[rev]))
+				cl, err = LoadCL(ui, repo, clname, web=False)
+				if err != "":
+					ui.warn("loading CL %s: %s\n" % (clname, err))
+					continue
+				if not cl.copied_from:
+					EditDesc(cl.name, closed=True, private=cl.private)
+				cl.Delete(ui, repo)
+
+	if hgversion < '1.4':
+		get = util.cachefunc(lambda r: repo[r].changeset())
+		changeiter, matchfn = cmdutil.walkchangerevs(ui, repo, [], get, {'rev': None})
+		n = 0
+		for st, rev, fns in changeiter:
+			if st != 'iter':
+				continue
+			n += 1
+			if n > 100:
+				break
+			Rev(rev)
+	else:
+		matchfn = scmutil.match(repo, [], {'rev': None})
+		def prep(ctx, fns):
+			pass
+		for ctx in cmdutil.walkchangerevs(repo, matchfn, {'rev': None}, prep):
+			Rev(ctx.rev())
+
+	# Remove files that are not modified from the CLs in which they appear.
+	all = LoadAllCL(ui, repo, web=False)
+	changed = ChangedFiles(ui, repo, [], {})
+	for _, cl in all.items():
+		extra = Sub(cl.files, changed)
+		if extra:
+			ui.warn("Removing unmodified files from CL %s:\n" % (cl.name,))
+			for f in extra:
+				ui.warn("\t%s\n" % (f,))
+			cl.files = Sub(cl.files, extra)
+			cl.Flush(ui, repo)
+		if not cl.files:
+			if not cl.copied_from:
+				ui.warn("CL %s has no files; delete (abandon) with hg change -d %s\n" % (cl.name, cl.name))
+			else:
+				ui.warn("CL %s has no files; delete locally with hg change -D %s\n" % (cl.name, cl.name))
+	return
+
+def upload(ui, repo, name, **opts):
+	"""upload diffs to the code review server
+
+	Uploads the current modifications for a given change to the server.
+	"""
+	if missing_codereview:
+		return missing_codereview
+
+	repo.ui.quiet = True
+	cl, err = LoadCL(ui, repo, name, web=True)
+	if err != "":
+		return err
+	if not cl.local:
+		return "cannot upload non-local change"
+	cl.Upload(ui, repo)
+	print "%s%s\n" % (server_url_base, cl.name)
+	return
+
+review_opts = [
+	('r', 'reviewer', '', 'add reviewer'),
+	('', 'cc', '', 'add cc'),
+	('', 'tbr', '', 'add future reviewer'),
+	('m', 'message', '', 'change description (for new change)'),
+]
+
+cmdtable = {
+	# The ^ means to show this command in the help text that
+	# is printed when running hg with no arguments.
+	"^change": (
+		change,
+		[
+			('d', 'delete', None, 'delete existing change list'),
+			('D', 'deletelocal', None, 'delete locally, but do not change CL on server'),
+			('i', 'stdin', None, 'read change list from standard input'),
+			('o', 'stdout', None, 'print change list to standard output'),
+			('p', 'pending', None, 'print pending summary to standard output'),
+		],
+		"[-d | -D] [-i] [-o] change# or FILE ..."
+	),
+	"^clpatch": (
+		clpatch,
+		[
+			('', 'ignore_hgpatch_failure', None, 'create CL metadata even if hgpatch fails'),
+			('', 'no_incoming', None, 'disable check for incoming changes'),
+		],
+		"change#"
+	),
+	# Would prefer to call this codereview-login, but then
+	# hg help codereview prints the help for this command
+	# instead of the help for the extension.
+	"code-login": (
+		code_login,
+		[],
+		"",
+	),
+	"^download": (
+		download,
+		[],
+		"change#"
+	),
+	"^file": (
+		file,
+		[
+			('d', 'delete', None, 'delete files from change list (but not repository)'),
+		],
+		"[-d] change# FILE ..."
+	),
+	"^gofmt": (
+		gofmt,
+		[
+			('l', 'list', None, 'list files that would change, but do not edit them'),
+		],
+		"FILE ..."
+	),
+	"^pending|p": (
+		pending,
+		[],
+		"[FILE ...]"
+	),
+	"^mail": (
+		mail,
+		review_opts + [
+		] + commands.walkopts,
+		"[-r reviewer] [--cc cc] [change# | file ...]"
+	),
+	"^release-apply": (
+		release_apply,
+		[
+			('', 'ignore_hgpatch_failure', None, 'create CL metadata even if hgpatch fails'),
+			('', 'no_incoming', None, 'disable check for incoming changes'),
+		],
+		"change#"
+	),
+	# TODO: release-start, release-tag, weekly-tag
+	"^submit": (
+		submit,
+		review_opts + [
+			('', 'no_incoming', None, 'disable initial incoming check (for testing)'),
+			('n', 'dryrun', None, 'make change only locally (for testing)'),
+		] + commands.walkopts + commands.commitopts + commands.commitopts2,
+		"[-r reviewer] [--cc cc] [change# | file ...]"
+	),
+	"^sync": (
+		sync,
+		[
+			('', 'local', None, 'do not pull changes from remote repository')
+		],
+		"[--local]",
+	),
+	"^undo": (
+		undo,
+		[
+			('', 'ignore_hgpatch_failure', None, 'create CL metadata even if hgpatch fails'),
+			('', 'no_incoming', None, 'disable check for incoming changes'),
+		],
+		"change#"
+	),
+	"^upload": (
+		upload,
+		[],
+		"change#"
+	),
+}
+
+
+#######################################################################
+# Wrappers around upload.py for interacting with Rietveld
+
+# HTML form parser
+class FormParser(HTMLParser):
+	def __init__(self):
+		self.map = {}
+		self.curtag = None
+		self.curdata = None
+		HTMLParser.__init__(self)
+	def handle_starttag(self, tag, attrs):
+		if tag == "input":
+			key = None
+			value = ''
+			for a in attrs:
+				if a[0] == 'name':
+					key = a[1]
+				if a[0] == 'value':
+					value = a[1]
+			if key is not None:
+				self.map[key] = value
+		if tag == "textarea":
+			key = None
+			for a in attrs:
+				if a[0] == 'name':
+					key = a[1]
+			if key is not None:
+				self.curtag = key
+				self.curdata = ''
+	def handle_endtag(self, tag):
+		if tag == "textarea" and self.curtag is not None:
+			self.map[self.curtag] = self.curdata
+			self.curtag = None
+			self.curdata = None
+	def handle_charref(self, name):
+		self.handle_data(unichr(int(name)))
+	def handle_entityref(self, name):
+		import htmlentitydefs
+		if name in htmlentitydefs.entitydefs:
+			self.handle_data(htmlentitydefs.entitydefs[name])
+		else:
+			self.handle_data("&" + name + ";")
+	def handle_data(self, data):
+		if self.curdata is not None:
+			self.curdata += data
+
+def JSONGet(ui, path):
+	try:
+		data = MySend(path, force_auth=False)
+		typecheck(data, str)
+		d = fix_json(json.loads(data))
+	except:
+		ui.warn("JSONGet %s: %s\n" % (path, ExceptionDetail()))
+		return None
+	return d
+
+# Clean up json parser output to match our expectations:
+#   * all strings are UTF-8-encoded str, not unicode.
+#   * missing fields are missing, not None,
+#     so that d.get("foo", defaultvalue) works.
+def fix_json(x):
+	if type(x) in [str, int, float, bool, type(None)]:
+		pass
+	elif type(x) is unicode:
+		x = x.encode("utf-8")
+	elif type(x) is list:
+		for i in range(len(x)):
+			x[i] = fix_json(x[i])
+	elif type(x) is dict:
+		todel = []
+		for k in x:
+			if x[k] is None:
+				todel.append(k)
+			else:
+				x[k] = fix_json(x[k])
+		for k in todel:
+			del x[k]
+	else:
+		raise util.Abort("unknown type " + str(type(x)) + " in fix_json")
+	if type(x) is str:
+		x = x.replace('\r\n', '\n')
+	return x
+
+def IsRietveldSubmitted(ui, clname, hex):
+	dict = JSONGet(ui, "/api/" + clname + "?messages=true")
+	if dict is None:
+		return False
+	for msg in dict.get("messages", []):
+		text = msg.get("text", "")
+		m = re.match('\*\*\* Submitted as [^*]*?([0-9a-f]+) \*\*\*', text)
+		if m is not None and len(m.group(1)) >= 8 and hex.startswith(m.group(1)):
+			return True
+	return False
+
+def IsRietveldMailed(cl):
+	for msg in cl.dict.get("messages", []):
+		if msg.get("text", "").find("I'd like you to review this change") >= 0:
+			return True
+	return False
+
+def DownloadCL(ui, repo, clname):
+	set_status("downloading CL " + clname)
+	cl, err = LoadCL(ui, repo, clname, web=True)
+	if err != "":
+		return None, None, None, "error loading CL %s: %s" % (clname, err)
+
+	# Find most recent diff
+	diffs = cl.dict.get("patchsets", [])
+	if not diffs:
+		return None, None, None, "CL has no patch sets"
+	patchid = diffs[-1]
+
+	patchset = JSONGet(ui, "/api/" + clname + "/" + str(patchid))
+	if patchset is None:
+		return None, None, None, "error loading CL patchset %s/%d" % (clname, patchid)
+	if patchset.get("patchset", 0) != patchid:
+		return None, None, None, "malformed patchset information"
+	
+	vers = ""
+	msg = patchset.get("message", "").split()
+	if len(msg) >= 3 and msg[0] == "diff" and msg[1] == "-r":
+		vers = msg[2]
+	diff = "/download/issue" + clname + "_" + str(patchid) + ".diff"
+
+	diffdata = MySend(diff, force_auth=False)
+	
+	# Print warning if email is not in CONTRIBUTORS file.
+	email = cl.dict.get("owner_email", "")
+	if not email:
+		return None, None, None, "cannot find owner for %s" % (clname)
+	him = FindContributor(ui, repo, email)
+	me = FindContributor(ui, repo, None)
+	if him == me:
+		cl.mailed = IsRietveldMailed(cl)
+	else:
+		cl.copied_from = email
+
+	return cl, vers, diffdata, ""
+
+def MySend(request_path, payload=None,
+		content_type="application/octet-stream",
+		timeout=None, force_auth=True,
+		**kwargs):
+	"""Run MySend1 maybe twice, because Rietveld is unreliable."""
+	try:
+		return MySend1(request_path, payload, content_type, timeout, force_auth, **kwargs)
+	except Exception, e:
+		if type(e) != urllib2.HTTPError or e.code != 500:	# only retry on HTTP 500 error
+			raise
+		print >>sys.stderr, "Loading "+request_path+": "+ExceptionDetail()+"; trying again in 2 seconds."
+		time.sleep(2)
+		return MySend1(request_path, payload, content_type, timeout, force_auth, **kwargs)
+
+# Like upload.py Send but only authenticates when the
+# redirect is to www.google.com/accounts.  This keeps
+# unnecessary redirects from happening during testing.
+def MySend1(request_path, payload=None,
+				content_type="application/octet-stream",
+				timeout=None, force_auth=True,
+				**kwargs):
+	"""Sends an RPC and returns the response.
+
+	Args:
+		request_path: The path to send the request to, eg /api/appversion/create.
+		payload: The body of the request, or None to send an empty request.
+		content_type: The Content-Type header to use.
+		timeout: timeout in seconds; default None i.e. no timeout.
+			(Note: for large requests on OS X, the timeout doesn't work right.)
+		kwargs: Any keyword arguments are converted into query string parameters.
+
+	Returns:
+		The response body, as a string.
+	"""
+	# TODO: Don't require authentication.  Let the server say
+	# whether it is necessary.
+	global rpc
+	if rpc == None:
+		rpc = GetRpcServer(upload_options)
+	self = rpc
+	if not self.authenticated and force_auth:
+		self._Authenticate()
+	if request_path is None:
+		return
+
+	old_timeout = socket.getdefaulttimeout()
+	socket.setdefaulttimeout(timeout)
+	try:
+		tries = 0
+		while True:
+			tries += 1
+			args = dict(kwargs)
+			url = "http://%s%s" % (self.host, request_path)
+			if args:
+				url += "?" + urllib.urlencode(args)
+			req = self._CreateRequest(url=url, data=payload)
+			req.add_header("Content-Type", content_type)
+			try:
+				f = self.opener.open(req)
+				response = f.read()
+				f.close()
+				# Translate \r\n into \n, because Rietveld doesn't.
+				response = response.replace('\r\n', '\n')
+				# who knows what urllib will give us
+				if type(response) == unicode:
+					response = response.encode("utf-8")
+				typecheck(response, str)
+				return response
+			except urllib2.HTTPError, e:
+				if tries > 3:
+					raise
+				elif e.code == 401:
+					self._Authenticate()
+				elif e.code == 302:
+					loc = e.info()["location"]
+					if not loc.startswith('https://www.google.com/a') or loc.find('/ServiceLogin') < 0:
+						return ''
+					self._Authenticate()
+				else:
+					raise
+	finally:
+		socket.setdefaulttimeout(old_timeout)
+
+def GetForm(url):
+	f = FormParser()
+	f.feed(ustr(MySend(url)))	# f.feed wants unicode
+	f.close()
+	# convert back to utf-8 to restore sanity
+	m = {}
+	for k,v in f.map.items():
+		m[k.encode("utf-8")] = v.replace("\r\n", "\n").encode("utf-8")
+	return m
+
+def EditDesc(issue, subject=None, desc=None, reviewers=None, cc=None, closed=False, private=False):
+	set_status("uploading change to description")
+	form_fields = GetForm("/" + issue + "/edit")
+	if subject is not None:
+		form_fields['subject'] = subject
+	if desc is not None:
+		form_fields['description'] = desc
+	if reviewers is not None:
+		form_fields['reviewers'] = reviewers
+	if cc is not None:
+		form_fields['cc'] = cc
+	if closed:
+		form_fields['closed'] = "checked"
+	if private:
+		form_fields['private'] = "checked"
+	ctype, body = EncodeMultipartFormData(form_fields.items(), [])
+	response = MySend("/" + issue + "/edit", body, content_type=ctype)
+	if response != "":
+		print >>sys.stderr, "Error editing description:\n" + "Sent form: \n", form_fields, "\n", response
+		sys.exit(2)
+
+def PostMessage(ui, issue, message, reviewers=None, cc=None, send_mail=True, subject=None):
+	set_status("uploading message")
+	form_fields = GetForm("/" + issue + "/publish")
+	if reviewers is not None:
+		form_fields['reviewers'] = reviewers
+	if cc is not None:
+		form_fields['cc'] = cc
+	if send_mail:
+		form_fields['send_mail'] = "checked"
+	else:
+		del form_fields['send_mail']
+	if subject is not None:
+		form_fields['subject'] = subject
+	form_fields['message'] = message
+	
+	form_fields['message_only'] = '1'	# Don't include draft comments
+	if reviewers is not None or cc is not None:
+		form_fields['message_only'] = ''	# Must set '' in order to override cc/reviewer
+	ctype = "applications/x-www-form-urlencoded"
+	body = urllib.urlencode(form_fields)
+	response = MySend("/" + issue + "/publish", body, content_type=ctype)
+	if response != "":
+		print response
+		sys.exit(2)
+
+class opt(object):
+	pass
+
+def nocommit(*pats, **opts):
+	"""(disabled when using this extension)"""
+	raise util.Abort("codereview extension enabled; use mail, upload, or submit instead of commit")
+
+def nobackout(*pats, **opts):
+	"""(disabled when using this extension)"""
+	raise util.Abort("codereview extension enabled; use undo instead of backout")
+
+def norollback(*pats, **opts):
+	"""(disabled when using this extension)"""
+	raise util.Abort("codereview extension enabled; use undo instead of rollback")
+
+def RietveldSetup(ui, repo):
+	global defaultcc, upload_options, rpc, server, server_url_base, force_google_account, verbosity, contributors
+	global missing_codereview
+
+	repo_config_path = ''
+	# Read repository-specific options from lib/codereview/codereview.cfg
+	try:
+		repo_config_path = repo.root + '/lib/codereview/codereview.cfg'
+		f = open(repo_config_path)
+		for line in f:
+			if line.startswith('defaultcc: '):
+				defaultcc = SplitCommaSpace(line[10:])
+	except:
+		# If there are no options, chances are good this is not
+		# a code review repository; stop now before we foul
+		# things up even worse.  Might also be that repo doesn't
+		# even have a root.  See issue 959.
+		if repo_config_path == '':
+			missing_codereview = 'codereview disabled: repository has no root'
+		else:
+			missing_codereview = 'codereview disabled: cannot open ' + repo_config_path
+		return
+
+	# Should only modify repository with hg submit.
+	# Disable the built-in Mercurial commands that might
+	# trip things up.
+	cmdutil.commit = nocommit
+	global real_rollback
+	real_rollback = repo.rollback
+	repo.rollback = norollback
+	# would install nobackout if we could; oh well
+
+	try:
+		f = open(repo.root + '/CONTRIBUTORS', 'r')
+	except:
+		raise util.Abort("cannot open %s: %s" % (repo.root+'/CONTRIBUTORS', ExceptionDetail()))
+	for line in f:
+		# CONTRIBUTORS is a list of lines like:
+		#	Person <email>
+		#	Person <email> <alt-email>
+		# The first email address is the one used in commit logs.
+		if line.startswith('#'):
+			continue
+		m = re.match(r"([^<>]+\S)\s+(<[^<>\s]+>)((\s+<[^<>\s]+>)*)\s*$", line)
+		if m:
+			name = m.group(1)
+			email = m.group(2)[1:-1]
+			contributors[email.lower()] = (name, email)
+			for extra in m.group(3).split():
+				contributors[extra[1:-1].lower()] = (name, email)
+
+	if not ui.verbose:
+		verbosity = 0
+
+	# Config options.
+	x = ui.config("codereview", "server")
+	if x is not None:
+		server = x
+
+	# TODO(rsc): Take from ui.username?
+	email = None
+	x = ui.config("codereview", "email")
+	if x is not None:
+		email = x
+
+	server_url_base = "http://" + server + "/"
+
+	testing = ui.config("codereview", "testing")
+	force_google_account = ui.configbool("codereview", "force_google_account", False)
+
+	upload_options = opt()
+	upload_options.email = email
+	upload_options.host = None
+	upload_options.verbose = 0
+	upload_options.description = None
+	upload_options.description_file = None
+	upload_options.reviewers = None
+	upload_options.cc = None
+	upload_options.message = None
+	upload_options.issue = None
+	upload_options.download_base = False
+	upload_options.revision = None
+	upload_options.send_mail = False
+	upload_options.vcs = None
+	upload_options.server = server
+	upload_options.save_cookies = True
+
+	if testing:
+		upload_options.save_cookies = False
+		upload_options.email = "test@example.com"
+
+	rpc = None
+	
+	global releaseBranch
+	tags = repo.branchtags().keys()
+	if 'release-branch.r100' in tags:
+		# NOTE(rsc): This tags.sort is going to get the wrong
+		# answer when comparing release-branch.r99 with
+		# release-branch.r100.  If we do ten releases a year
+		# that gives us 4 years before we have to worry about this.
+		raise util.Abort('tags.sort needs to be fixed for release-branch.r100')
+	tags.sort()
+	for t in tags:
+		if t.startswith('release-branch.'):
+			releaseBranch = t			
+
+#######################################################################
+# http://codereview.appspot.com/static/upload.py, heavily edited.
+
+#!/usr/bin/env python
+#
+# Copyright 2007 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#	http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Tool for uploading diffs from a version control system to the codereview app.
+
+Usage summary: upload.py [options] [-- diff_options]
+
+Diff options are passed to the diff command of the underlying system.
+
+Supported version control systems:
+	Git
+	Mercurial
+	Subversion
+
+It is important for Git/Mercurial users to specify a tree/node/branch to diff
+against by using the '--rev' option.
+"""
+# This code is derived from appcfg.py in the App Engine SDK (open source),
+# and from ASPN recipe #146306.
+
+import cookielib
+import getpass
+import logging
+import mimetypes
+import optparse
+import os
+import re
+import socket
+import subprocess
+import sys
+import urllib
+import urllib2
+import urlparse
+
+# The md5 module was deprecated in Python 2.5.
+try:
+	from hashlib import md5
+except ImportError:
+	from md5 import md5
+
+try:
+	import readline
+except ImportError:
+	pass
+
+# The logging verbosity:
+#  0: Errors only.
+#  1: Status messages.
+#  2: Info logs.
+#  3: Debug logs.
+verbosity = 1
+
+# Max size of patch or base file.
+MAX_UPLOAD_SIZE = 900 * 1024
+
+# whitelist for non-binary filetypes which do not start with "text/"
+# .mm (Objective-C) shows up as application/x-freemind on my Linux box.
+TEXT_MIMETYPES = [
+	'application/javascript',
+	'application/x-javascript',
+	'application/x-freemind'
+]
+
+def GetEmail(prompt):
+	"""Prompts the user for their email address and returns it.
+
+	The last used email address is saved to a file and offered up as a suggestion
+	to the user. If the user presses enter without typing in anything the last
+	used email address is used. If the user enters a new address, it is saved
+	for next time we prompt.
+
+	"""
+	last_email_file_name = os.path.expanduser("~/.last_codereview_email_address")
+	last_email = ""
+	if os.path.exists(last_email_file_name):
+		try:
+			last_email_file = open(last_email_file_name, "r")
+			last_email = last_email_file.readline().strip("\n")
+			last_email_file.close()
+			prompt += " [%s]" % last_email
+		except IOError, e:
+			pass
+	email = raw_input(prompt + ": ").strip()
+	if email:
+		try:
+			last_email_file = open(last_email_file_name, "w")
+			last_email_file.write(email)
+			last_email_file.close()
+		except IOError, e:
+			pass
+	else:
+		email = last_email
+	return email
+
+
+def StatusUpdate(msg):
+	"""Print a status message to stdout.
+
+	If 'verbosity' is greater than 0, print the message.
+
+	Args:
+		msg: The string to print.
+	"""
+	if verbosity > 0:
+		print msg
+
+
+def ErrorExit(msg):
+	"""Print an error message to stderr and exit."""
+	print >>sys.stderr, msg
+	sys.exit(1)
+
+
+class ClientLoginError(urllib2.HTTPError):
+	"""Raised to indicate there was an error authenticating with ClientLogin."""
+
+	def __init__(self, url, code, msg, headers, args):
+		urllib2.HTTPError.__init__(self, url, code, msg, headers, None)
+		self.args = args
+		self.reason = args["Error"]
+
+
+class AbstractRpcServer(object):
+	"""Provides a common interface for a simple RPC server."""
+
+	def __init__(self, host, auth_function, host_override=None, extra_headers={}, save_cookies=False):
+		"""Creates a new HttpRpcServer.
+
+		Args:
+			host: The host to send requests to.
+			auth_function: A function that takes no arguments and returns an
+				(email, password) tuple when called. Will be called if authentication
+				is required.
+			host_override: The host header to send to the server (defaults to host).
+			extra_headers: A dict of extra headers to append to every request.
+			save_cookies: If True, save the authentication cookies to local disk.
+				If False, use an in-memory cookiejar instead.  Subclasses must
+				implement this functionality.  Defaults to False.
+		"""
+		self.host = host
+		self.host_override = host_override
+		self.auth_function = auth_function
+		self.authenticated = False
+		self.extra_headers = extra_headers
+		self.save_cookies = save_cookies
+		self.opener = self._GetOpener()
+		if self.host_override:
+			logging.info("Server: %s; Host: %s", self.host, self.host_override)
+		else:
+			logging.info("Server: %s", self.host)
+
+	def _GetOpener(self):
+		"""Returns an OpenerDirector for making HTTP requests.
+
+		Returns:
+			A urllib2.OpenerDirector object.
+		"""
+		raise NotImplementedError()
+
+	def _CreateRequest(self, url, data=None):
+		"""Creates a new urllib request."""
+		logging.debug("Creating request for: '%s' with payload:\n%s", url, data)
+		req = urllib2.Request(url, data=data)
+		if self.host_override:
+			req.add_header("Host", self.host_override)
+		for key, value in self.extra_headers.iteritems():
+			req.add_header(key, value)
+		return req
+
+	def _GetAuthToken(self, email, password):
+		"""Uses ClientLogin to authenticate the user, returning an auth token.
+
+		Args:
+			email:    The user's email address
+			password: The user's password
+
+		Raises:
+			ClientLoginError: If there was an error authenticating with ClientLogin.
+			HTTPError: If there was some other form of HTTP error.
+
+		Returns:
+			The authentication token returned by ClientLogin.
+		"""
+		account_type = "GOOGLE"
+		if self.host.endswith(".google.com") and not force_google_account:
+			# Needed for use inside Google.
+			account_type = "HOSTED"
+		req = self._CreateRequest(
+				url="https://www.google.com/accounts/ClientLogin",
+				data=urllib.urlencode({
+						"Email": email,
+						"Passwd": password,
+						"service": "ah",
+						"source": "rietveld-codereview-upload",
+						"accountType": account_type,
+				}),
+		)
+		try:
+			response = self.opener.open(req)
+			response_body = response.read()
+			response_dict = dict(x.split("=") for x in response_body.split("\n") if x)
+			return response_dict["Auth"]
+		except urllib2.HTTPError, e:
+			if e.code == 403:
+				body = e.read()
+				response_dict = dict(x.split("=", 1) for x in body.split("\n") if x)
+				raise ClientLoginError(req.get_full_url(), e.code, e.msg, e.headers, response_dict)
+			else:
+				raise
+
+	def _GetAuthCookie(self, auth_token):
+		"""Fetches authentication cookies for an authentication token.
+
+		Args:
+			auth_token: The authentication token returned by ClientLogin.
+
+		Raises:
+			HTTPError: If there was an error fetching the authentication cookies.
+		"""
+		# This is a dummy value to allow us to identify when we're successful.
+		continue_location = "http://localhost/"
+		args = {"continue": continue_location, "auth": auth_token}
+		req = self._CreateRequest("http://%s/_ah/login?%s" % (self.host, urllib.urlencode(args)))
+		try:
+			response = self.opener.open(req)
+		except urllib2.HTTPError, e:
+			response = e
+		if (response.code != 302 or
+				response.info()["location"] != continue_location):
+			raise urllib2.HTTPError(req.get_full_url(), response.code, response.msg, response.headers, response.fp)
+		self.authenticated = True
+
+	def _Authenticate(self):
+		"""Authenticates the user.
+
+		The authentication process works as follows:
+		1) We get a username and password from the user
+		2) We use ClientLogin to obtain an AUTH token for the user
+				(see http://code.google.com/apis/accounts/AuthForInstalledApps.html).
+		3) We pass the auth token to /_ah/login on the server to obtain an
+				authentication cookie. If login was successful, it tries to redirect
+				us to the URL we provided.
+
+		If we attempt to access the upload API without first obtaining an
+		authentication cookie, it returns a 401 response (or a 302) and
+		directs us to authenticate ourselves with ClientLogin.
+		"""
+		for i in range(3):
+			credentials = self.auth_function()
+			try:
+				auth_token = self._GetAuthToken(credentials[0], credentials[1])
+			except ClientLoginError, e:
+				if e.reason == "BadAuthentication":
+					print >>sys.stderr, "Invalid username or password."
+					continue
+				if e.reason == "CaptchaRequired":
+					print >>sys.stderr, (
+						"Please go to\n"
+						"https://www.google.com/accounts/DisplayUnlockCaptcha\n"
+						"and verify you are a human.  Then try again.")
+					break
+				if e.reason == "NotVerified":
+					print >>sys.stderr, "Account not verified."
+					break
+				if e.reason == "TermsNotAgreed":
+					print >>sys.stderr, "User has not agreed to TOS."
+					break
+				if e.reason == "AccountDeleted":
+					print >>sys.stderr, "The user account has been deleted."
+					break
+				if e.reason == "AccountDisabled":
+					print >>sys.stderr, "The user account has been disabled."
+					break
+				if e.reason == "ServiceDisabled":
+					print >>sys.stderr, "The user's access to the service has been disabled."
+					break
+				if e.reason == "ServiceUnavailable":
+					print >>sys.stderr, "The service is not available; try again later."
+					break
+				raise
+			self._GetAuthCookie(auth_token)
+			return
+
+	def Send(self, request_path, payload=None,
+					content_type="application/octet-stream",
+					timeout=None,
+					**kwargs):
+		"""Sends an RPC and returns the response.
+
+		Args:
+			request_path: The path to send the request to, eg /api/appversion/create.
+			payload: The body of the request, or None to send an empty request.
+			content_type: The Content-Type header to use.
+			timeout: timeout in seconds; default None i.e. no timeout.
+				(Note: for large requests on OS X, the timeout doesn't work right.)
+			kwargs: Any keyword arguments are converted into query string parameters.
+
+		Returns:
+			The response body, as a string.
+		"""
+		# TODO: Don't require authentication.  Let the server say
+		# whether it is necessary.
+		if not self.authenticated:
+			self._Authenticate()
+
+		old_timeout = socket.getdefaulttimeout()
+		socket.setdefaulttimeout(timeout)
+		try:
+			tries = 0
+			while True:
+				tries += 1
+				args = dict(kwargs)
+				url = "http://%s%s" % (self.host, request_path)
+				if args:
+					url += "?" + urllib.urlencode(args)
+				req = self._CreateRequest(url=url, data=payload)
+				req.add_header("Content-Type", content_type)
+				try:
+					f = self.opener.open(req)
+					response = f.read()
+					f.close()
+					return response
+				except urllib2.HTTPError, e:
+					if tries > 3:
+						raise
+					elif e.code == 401 or e.code == 302:
+						self._Authenticate()
+					else:
+						raise
+		finally:
+			socket.setdefaulttimeout(old_timeout)
+
+
+class HttpRpcServer(AbstractRpcServer):
+	"""Provides a simplified RPC-style interface for HTTP requests."""
+
+	def _Authenticate(self):
+		"""Save the cookie jar after authentication."""
+		super(HttpRpcServer, self)._Authenticate()
+		if self.save_cookies:
+			StatusUpdate("Saving authentication cookies to %s" % self.cookie_file)
+			self.cookie_jar.save()
+
+	def _GetOpener(self):
+		"""Returns an OpenerDirector that supports cookies and ignores redirects.
+
+		Returns:
+			A urllib2.OpenerDirector object.
+		"""
+		opener = urllib2.OpenerDirector()
+		opener.add_handler(urllib2.ProxyHandler())
+		opener.add_handler(urllib2.UnknownHandler())
+		opener.add_handler(urllib2.HTTPHandler())
+		opener.add_handler(urllib2.HTTPDefaultErrorHandler())
+		opener.add_handler(urllib2.HTTPSHandler())
+		opener.add_handler(urllib2.HTTPErrorProcessor())
+		if self.save_cookies:
+			self.cookie_file = os.path.expanduser("~/.codereview_upload_cookies_" + server)
+			self.cookie_jar = cookielib.MozillaCookieJar(self.cookie_file)
+			if os.path.exists(self.cookie_file):
+				try:
+					self.cookie_jar.load()
+					self.authenticated = True
+					StatusUpdate("Loaded authentication cookies from %s" % self.cookie_file)
+				except (cookielib.LoadError, IOError):
+					# Failed to load cookies - just ignore them.
+					pass
+			else:
+				# Create an empty cookie file with mode 600
+				fd = os.open(self.cookie_file, os.O_CREAT, 0600)
+				os.close(fd)
+			# Always chmod the cookie file
+			os.chmod(self.cookie_file, 0600)
+		else:
+			# Don't save cookies across runs of update.py.
+			self.cookie_jar = cookielib.CookieJar()
+		opener.add_handler(urllib2.HTTPCookieProcessor(self.cookie_jar))
+		return opener
+
+
+def GetRpcServer(options):
+	"""Returns an instance of an AbstractRpcServer.
+
+	Returns:
+		A new AbstractRpcServer, on which RPC calls can be made.
+	"""
+
+	rpc_server_class = HttpRpcServer
+
+	def GetUserCredentials():
+		"""Prompts the user for a username and password."""
+		# Disable status prints so they don't obscure the password prompt.
+		global global_status
+		st = global_status
+		global_status = None
+
+		email = options.email
+		if email is None:
+			email = GetEmail("Email (login for uploading to %s)" % options.server)
+		password = getpass.getpass("Password for %s: " % email)
+
+		# Put status back.
+		global_status = st
+		return (email, password)
+
+	# If this is the dev_appserver, use fake authentication.
+	host = (options.host or options.server).lower()
+	if host == "localhost" or host.startswith("localhost:"):
+		email = options.email
+		if email is None:
+			email = "test@example.com"
+			logging.info("Using debug user %s.  Override with --email" % email)
+		server = rpc_server_class(
+				options.server,
+				lambda: (email, "password"),
+				host_override=options.host,
+				extra_headers={"Cookie": 'dev_appserver_login="%s:False"' % email},
+				save_cookies=options.save_cookies)
+		# Don't try to talk to ClientLogin.
+		server.authenticated = True
+		return server
+
+	return rpc_server_class(options.server, GetUserCredentials,
+		host_override=options.host, save_cookies=options.save_cookies)
+
+
+def EncodeMultipartFormData(fields, files):
+	"""Encode form fields for multipart/form-data.
+
+	Args:
+		fields: A sequence of (name, value) elements for regular form fields.
+		files: A sequence of (name, filename, value) elements for data to be
+					uploaded as files.
+	Returns:
+		(content_type, body) ready for httplib.HTTP instance.
+
+	Source:
+		http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/146306
+	"""
+	BOUNDARY = '-M-A-G-I-C---B-O-U-N-D-A-R-Y-'
+	CRLF = '\r\n'
+	lines = []
+	for (key, value) in fields:
+		typecheck(key, str)
+		typecheck(value, str)
+		lines.append('--' + BOUNDARY)
+		lines.append('Content-Disposition: form-data; name="%s"' % key)
+		lines.append('')
+		lines.append(value)
+	for (key, filename, value) in files:
+		typecheck(key, str)
+		typecheck(filename, str)
+		typecheck(value, str)
+		lines.append('--' + BOUNDARY)
+		lines.append('Content-Disposition: form-data; name="%s"; filename="%s"' % (key, filename))
+		lines.append('Content-Type: %s' % GetContentType(filename))
+		lines.append('')
+		lines.append(value)
+	lines.append('--' + BOUNDARY + '--')
+	lines.append('')
+	body = CRLF.join(lines)
+	content_type = 'multipart/form-data; boundary=%s' % BOUNDARY
+	return content_type, body
+
+
+def GetContentType(filename):
+	"""Helper to guess the content-type from the filename."""
+	return mimetypes.guess_type(filename)[0] or 'application/octet-stream'
+
+
+# Use a shell for subcommands on Windows to get a PATH search.
+use_shell = sys.platform.startswith("win")
+
+def RunShellWithReturnCode(command, print_output=False,
+		universal_newlines=True, env=os.environ):
+	"""Executes a command and returns the output from stdout and the return code.
+
+	Args:
+		command: Command to execute.
+		print_output: If True, the output is printed to stdout.
+			If False, both stdout and stderr are ignored.
+		universal_newlines: Use universal_newlines flag (default: True).
+
+	Returns:
+		Tuple (output, return code)
+	"""
+	logging.info("Running %s", command)
+	p = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+		shell=use_shell, universal_newlines=universal_newlines, env=env)
+	if print_output:
+		output_array = []
+		while True:
+			line = p.stdout.readline()
+			if not line:
+				break
+			print line.strip("\n")
+			output_array.append(line)
+		output = "".join(output_array)
+	else:
+		output = p.stdout.read()
+	p.wait()
+	errout = p.stderr.read()
+	if print_output and errout:
+		print >>sys.stderr, errout
+	p.stdout.close()
+	p.stderr.close()
+	return output, p.returncode
+
+
+def RunShell(command, silent_ok=False, universal_newlines=True,
+		print_output=False, env=os.environ):
+	data, retcode = RunShellWithReturnCode(command, print_output, universal_newlines, env)
+	if retcode:
+		ErrorExit("Got error status from %s:\n%s" % (command, data))
+	if not silent_ok and not data:
+		ErrorExit("No output from %s" % command)
+	return data
+
+
+class VersionControlSystem(object):
+	"""Abstract base class providing an interface to the VCS."""
+
+	def __init__(self, options):
+		"""Constructor.
+
+		Args:
+			options: Command line options.
+		"""
+		self.options = options
+
+	def GenerateDiff(self, args):
+		"""Return the current diff as a string.
+
+		Args:
+			args: Extra arguments to pass to the diff command.
+		"""
+		raise NotImplementedError(
+				"abstract method -- subclass %s must override" % self.__class__)
+
+	def GetUnknownFiles(self):
+		"""Return a list of files unknown to the VCS."""
+		raise NotImplementedError(
+				"abstract method -- subclass %s must override" % self.__class__)
+
+	def CheckForUnknownFiles(self):
+		"""Show an "are you sure?" prompt if there are unknown files."""
+		unknown_files = self.GetUnknownFiles()
+		if unknown_files:
+			print "The following files are not added to version control:"
+			for line in unknown_files:
+				print line
+			prompt = "Are you sure to continue?(y/N) "
+			answer = raw_input(prompt).strip()
+			if answer != "y":
+				ErrorExit("User aborted")
+
+	def GetBaseFile(self, filename):
+		"""Get the content of the upstream version of a file.
+
+		Returns:
+			A tuple (base_content, new_content, is_binary, status)
+				base_content: The contents of the base file.
+				new_content: For text files, this is empty.  For binary files, this is
+					the contents of the new file, since the diff output won't contain
+					information to reconstruct the current file.
+				is_binary: True iff the file is binary.
+				status: The status of the file.
+		"""
+
+		raise NotImplementedError(
+				"abstract method -- subclass %s must override" % self.__class__)
+
+
+	def GetBaseFiles(self, diff):
+		"""Helper that calls GetBase file for each file in the patch.
+
+		Returns:
+			A dictionary that maps from filename to GetBaseFile's tuple.  Filenames
+			are retrieved based on lines that start with "Index:" or
+			"Property changes on:".
+		"""
+		files = {}
+		for line in diff.splitlines(True):
+			if line.startswith('Index:') or line.startswith('Property changes on:'):
+				unused, filename = line.split(':', 1)
+				# On Windows if a file has property changes its filename uses '\'
+				# instead of '/'.
+				filename = filename.strip().replace('\\', '/')
+				files[filename] = self.GetBaseFile(filename)
+		return files
+
+
+	def UploadBaseFiles(self, issue, rpc_server, patch_list, patchset, options,
+											files):
+		"""Uploads the base files (and if necessary, the current ones as well)."""
+
+		def UploadFile(filename, file_id, content, is_binary, status, is_base):
+			"""Uploads a file to the server."""
+			set_status("uploading " + filename)
+			file_too_large = False
+			if is_base:
+				type = "base"
+			else:
+				type = "current"
+			if len(content) > MAX_UPLOAD_SIZE:
+				print ("Not uploading the %s file for %s because it's too large." %
+							(type, filename))
+				file_too_large = True
+				content = ""
+			checksum = md5(content).hexdigest()
+			if options.verbose > 0 and not file_too_large:
+				print "Uploading %s file for %s" % (type, filename)
+			url = "/%d/upload_content/%d/%d" % (int(issue), int(patchset), file_id)
+			form_fields = [
+				("filename", filename),
+				("status", status),
+				("checksum", checksum),
+				("is_binary", str(is_binary)),
+				("is_current", str(not is_base)),
+			]
+			if file_too_large:
+				form_fields.append(("file_too_large", "1"))
+			if options.email:
+				form_fields.append(("user", options.email))
+			ctype, body = EncodeMultipartFormData(form_fields, [("data", filename, content)])
+			response_body = rpc_server.Send(url, body, content_type=ctype)
+			if not response_body.startswith("OK"):
+				StatusUpdate("  --> %s" % response_body)
+				sys.exit(1)
+
+		# Don't want to spawn too many threads, nor do we want to
+		# hit Rietveld too hard, or it will start serving 500 errors.
+		# When 8 works, it's no better than 4, and sometimes 8 is
+		# too many for Rietveld to handle.
+		MAX_PARALLEL_UPLOADS = 4
+
+		sema = threading.BoundedSemaphore(MAX_PARALLEL_UPLOADS)
+		upload_threads = []
+		finished_upload_threads = []
+		
+		class UploadFileThread(threading.Thread):
+			def __init__(self, args):
+				threading.Thread.__init__(self)
+				self.args = args
+			def run(self):
+				UploadFile(*self.args)
+				finished_upload_threads.append(self)
+				sema.release()
+
+		def StartUploadFile(*args):
+			sema.acquire()
+			while len(finished_upload_threads) > 0:
+				t = finished_upload_threads.pop()
+				upload_threads.remove(t)
+				t.join()
+			t = UploadFileThread(args)
+			upload_threads.append(t)
+			t.start()
+
+		def WaitForUploads():			
+			for t in upload_threads:
+				t.join()
+
+		patches = dict()
+		[patches.setdefault(v, k) for k, v in patch_list]
+		for filename in patches.keys():
+			base_content, new_content, is_binary, status = files[filename]
+			file_id_str = patches.get(filename)
+			if file_id_str.find("nobase") != -1:
+				base_content = None
+				file_id_str = file_id_str[file_id_str.rfind("_") + 1:]
+			file_id = int(file_id_str)
+			if base_content != None:
+				StartUploadFile(filename, file_id, base_content, is_binary, status, True)
+			if new_content != None:
+				StartUploadFile(filename, file_id, new_content, is_binary, status, False)
+		WaitForUploads()
+
+	def IsImage(self, filename):
+		"""Returns true if the filename has an image extension."""
+		mimetype =  mimetypes.guess_type(filename)[0]
+		if not mimetype:
+			return False
+		return mimetype.startswith("image/")
+
+	def IsBinary(self, filename):
+		"""Returns true if the guessed mimetyped isnt't in text group."""
+		mimetype = mimetypes.guess_type(filename)[0]
+		if not mimetype:
+			return False  # e.g. README, "real" binaries usually have an extension
+		# special case for text files which don't start with text/
+		if mimetype in TEXT_MIMETYPES:
+			return False
+		return not mimetype.startswith("text/")
+
+class FakeMercurialUI(object):
+	def __init__(self):
+		self.quiet = True
+		self.output = ''
+	
+	def write(self, *args, **opts):
+		self.output += ' '.join(args)
+
+use_hg_shell = False	# set to True to shell out to hg always; slower
+
+class MercurialVCS(VersionControlSystem):
+	"""Implementation of the VersionControlSystem interface for Mercurial."""
+
+	def __init__(self, options, ui, repo):
+		super(MercurialVCS, self).__init__(options)
+		self.ui = ui
+		self.repo = repo
+		# Absolute path to repository (we can be in a subdir)
+		self.repo_dir = os.path.normpath(repo.root)
+		# Compute the subdir
+		cwd = os.path.normpath(os.getcwd())
+		assert cwd.startswith(self.repo_dir)
+		self.subdir = cwd[len(self.repo_dir):].lstrip(r"\/")
+		if self.options.revision:
+			self.base_rev = self.options.revision
+		else:
+			mqparent, err = RunShellWithReturnCode(['hg', 'log', '--rev', 'qparent', '--template={node}'])
+			if not err and mqparent != "":
+				self.base_rev = mqparent
+			else:
+				self.base_rev = RunShell(["hg", "parents", "-q"]).split(':')[1].strip()
+	def _GetRelPath(self, filename):
+		"""Get relative path of a file according to the current directory,
+		given its logical path in the repo."""
+		assert filename.startswith(self.subdir), (filename, self.subdir)
+		return filename[len(self.subdir):].lstrip(r"\/")
+
+	def GenerateDiff(self, extra_args):
+		# If no file specified, restrict to the current subdir
+		extra_args = extra_args or ["."]
+		cmd = ["hg", "diff", "--git", "-r", self.base_rev] + extra_args
+		data = RunShell(cmd, silent_ok=True)
+		svndiff = []
+		filecount = 0
+		for line in data.splitlines():
+			m = re.match("diff --git a/(\S+) b/(\S+)", line)
+			if m:
+				# Modify line to make it look like as it comes from svn diff.
+				# With this modification no changes on the server side are required
+				# to make upload.py work with Mercurial repos.
+				# NOTE: for proper handling of moved/copied files, we have to use
+				# the second filename.
+				filename = m.group(2)
+				svndiff.append("Index: %s" % filename)
+				svndiff.append("=" * 67)
+				filecount += 1
+				logging.info(line)
+			else:
+				svndiff.append(line)
+		if not filecount:
+			ErrorExit("No valid patches found in output from hg diff")
+		return "\n".join(svndiff) + "\n"
+
+	def GetUnknownFiles(self):
+		"""Return a list of files unknown to the VCS."""
+		args = []
+		status = RunShell(["hg", "status", "--rev", self.base_rev, "-u", "."],
+				silent_ok=True)
+		unknown_files = []
+		for line in status.splitlines():
+			st, fn = line.split(" ", 1)
+			if st == "?":
+				unknown_files.append(fn)
+		return unknown_files
+
+	def GetBaseFile(self, filename):
+		set_status("inspecting " + filename)
+		# "hg status" and "hg cat" both take a path relative to the current subdir
+		# rather than to the repo root, but "hg diff" has given us the full path
+		# to the repo root.
+		base_content = ""
+		new_content = None
+		is_binary = False
+		oldrelpath = relpath = self._GetRelPath(filename)
+		# "hg status -C" returns two lines for moved/copied files, one otherwise
+		if use_hg_shell:
+			out = RunShell(["hg", "status", "-C", "--rev", self.base_rev, relpath])
+		else:
+			fui = FakeMercurialUI()
+			ret = commands.status(fui, self.repo, *[relpath], **{'rev': [self.base_rev], 'copies': True})
+			if ret:
+				raise util.Abort(ret)
+			out = fui.output
+		out = out.splitlines()
+		# HACK: strip error message about missing file/directory if it isn't in
+		# the working copy
+		if out[0].startswith('%s: ' % relpath):
+			out = out[1:]
+		status, what = out[0].split(' ', 1)
+		if len(out) > 1 and status == "A" and what == relpath:
+			oldrelpath = out[1].strip()
+			status = "M"
+		if ":" in self.base_rev:
+			base_rev = self.base_rev.split(":", 1)[0]
+		else:
+			base_rev = self.base_rev
+		if status != "A":
+			if use_hg_shell:
+				base_content = RunShell(["hg", "cat", "-r", base_rev, oldrelpath], silent_ok=True)
+			else:
+				base_content = str(self.repo[base_rev][oldrelpath].data())
+			is_binary = "\0" in base_content  # Mercurial's heuristic
+		if status != "R":
+			new_content = open(relpath, "rb").read()
+			is_binary = is_binary or "\0" in new_content
+		if is_binary and base_content and use_hg_shell:
+			# Fetch again without converting newlines
+			base_content = RunShell(["hg", "cat", "-r", base_rev, oldrelpath],
+				silent_ok=True, universal_newlines=False)
+		if not is_binary or not self.IsImage(relpath):
+			new_content = None
+		return base_content, new_content, is_binary, status
+
+
+# NOTE: The SplitPatch function is duplicated in engine.py, keep them in sync.
+def SplitPatch(data):
+	"""Splits a patch into separate pieces for each file.
+
+	Args:
+		data: A string containing the output of svn diff.
+
+	Returns:
+		A list of 2-tuple (filename, text) where text is the svn diff output
+			pertaining to filename.
+	"""
+	patches = []
+	filename = None
+	diff = []
+	for line in data.splitlines(True):
+		new_filename = None
+		if line.startswith('Index:'):
+			unused, new_filename = line.split(':', 1)
+			new_filename = new_filename.strip()
+		elif line.startswith('Property changes on:'):
+			unused, temp_filename = line.split(':', 1)
+			# When a file is modified, paths use '/' between directories, however
+			# when a property is modified '\' is used on Windows.  Make them the same
+			# otherwise the file shows up twice.
+			temp_filename = temp_filename.strip().replace('\\', '/')
+			if temp_filename != filename:
+				# File has property changes but no modifications, create a new diff.
+				new_filename = temp_filename
+		if new_filename:
+			if filename and diff:
+				patches.append((filename, ''.join(diff)))
+			filename = new_filename
+			diff = [line]
+			continue
+		if diff is not None:
+			diff.append(line)
+	if filename and diff:
+		patches.append((filename, ''.join(diff)))
+	return patches
+
+
+def UploadSeparatePatches(issue, rpc_server, patchset, data, options):
+	"""Uploads a separate patch for each file in the diff output.
+
+	Returns a list of [patch_key, filename] for each file.
+	"""
+	patches = SplitPatch(data)
+	rv = []
+	for patch in patches:
+		set_status("uploading patch for " + patch[0])
+		if len(patch[1]) > MAX_UPLOAD_SIZE:
+			print ("Not uploading the patch for " + patch[0] +
+				" because the file is too large.")
+			continue
+		form_fields = [("filename", patch[0])]
+		if not options.download_base:
+			form_fields.append(("content_upload", "1"))
+		files = [("data", "data.diff", patch[1])]
+		ctype, body = EncodeMultipartFormData(form_fields, files)
+		url = "/%d/upload_patch/%d" % (int(issue), int(patchset))
+		print "Uploading patch for " + patch[0]
+		response_body = rpc_server.Send(url, body, content_type=ctype)
+		lines = response_body.splitlines()
+		if not lines or lines[0] != "OK":
+			StatusUpdate("  --> %s" % response_body)
+			sys.exit(1)
+		rv.append([lines[1], patch[0]])
+	return rv
diff --git a/uuid/LICENSE b/uuid/LICENSE
new file mode 100644
index 0000000..ab6b011
--- /dev/null
+++ b/uuid/LICENSE
@@ -0,0 +1,27 @@
+Copyright (c) 2009 Google Inc. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/uuid/Makefile b/uuid/Makefile
new file mode 100644
index 0000000..2000732
--- /dev/null
+++ b/uuid/Makefile
@@ -0,0 +1,18 @@
+# Copyright 2011 Google Inc.  All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+include ${GOROOT}/src/Make.inc
+
+TARG=go-uuid.googlecode.com/hg/uuid
+GOFILES=\
+	hash.go\
+	dce.go\
+	node.go\
+	uuid.go\
+	util.go\
+	time.go\
+	version1.go\
+	version4.go\
+
+include ${GOROOT}/src/Make.pkg
diff --git a/dce.go b/uuid/dce.go
similarity index 77%
rename from dce.go
rename to uuid/dce.go
index dcdb358..7dd5b7b 100755
--- a/dce.go
+++ b/uuid/dce.go
@@ -1,17 +1,6 @@
 // Copyright 2011 Google Inc.  All rights reserved.
-// Author: borman@google.com (Paul Borman)
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
 
 package uuid
 
diff --git a/hash.go b/uuid/hash.go
similarity index 73%
rename from hash.go
rename to uuid/hash.go
index 66da82a..16f08cc 100644
--- a/hash.go
+++ b/uuid/hash.go
@@ -1,17 +1,6 @@
 // Copyright 2011 Google Inc.  All rights reserved.
-// Author: borman@google.com (Paul Borman)
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
 
 package uuid
 
diff --git a/node.go b/uuid/node.go
similarity index 79%
rename from node.go
rename to uuid/node.go
index 664d541..fd607b4 100755
--- a/node.go
+++ b/uuid/node.go
@@ -1,17 +1,6 @@
 // Copyright 2011 Google Inc.  All rights reserved.
-// Author: borman@google.com (Paul Borman)
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
 
 package uuid
 
diff --git a/time.go b/uuid/time.go
similarity index 84%
rename from time.go
rename to uuid/time.go
index f74ef6e..27625e6 100755
--- a/time.go
+++ b/uuid/time.go
@@ -1,17 +1,6 @@
 // Copyright 2011 Google Inc.  All rights reserved.
-// Author: borman@google.com (Paul Borman)
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
 
 package uuid
 
diff --git a/util.go b/uuid/util.go
similarity index 74%
rename from util.go
rename to uuid/util.go
index 77e6d5f..748ca2a 100644
--- a/util.go
+++ b/uuid/util.go
@@ -1,17 +1,6 @@
 // Copyright 2011 Google Inc.  All rights reserved.
-// Author: borman@google.com (Paul Borman)
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
 
 package uuid
 
diff --git a/uuid.go b/uuid/uuid.go
similarity index 85%
rename from uuid.go
rename to uuid/uuid.go
index 2b050e5..96e56e2 100755
--- a/uuid.go
+++ b/uuid/uuid.go
@@ -1,17 +1,6 @@
 // Copyright 2011 Google Inc.  All rights reserved.
-// Author: borman@google.com (Paul Borman)
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
 
 // The uuid package generates and inspects UUIDs based on RFC 4122 and
 // DCE 1.1: Authentication and Security Services.
diff --git a/uuid_test.go b/uuid/uuid_test.go
similarity index 93%
rename from uuid_test.go
rename to uuid/uuid_test.go
index 6f35399..573b3bc 100755
--- a/uuid_test.go
+++ b/uuid/uuid_test.go
@@ -1,17 +1,6 @@
 // Copyright 2011 Google Inc.  All rights reserved.
-// Author: borman@google.com (Paul Borman)
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
 
 package uuid
 
diff --git a/version1.go b/uuid/version1.go
similarity index 63%
rename from version1.go
rename to uuid/version1.go
index 6f92fda..6358004 100644
--- a/version1.go
+++ b/uuid/version1.go
@@ -1,17 +1,6 @@
 // Copyright 2011 Google Inc.  All rights reserved.
-// Author: borman@google.com (Paul Borman)
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
 
 package uuid
 
diff --git a/uuid/version4.go b/uuid/version4.go
new file mode 100644
index 0000000..b3d4a36
--- /dev/null
+++ b/uuid/version4.go
@@ -0,0 +1,25 @@
+// Copyright 2011 Google Inc.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package uuid
+
+// Random returns a Random (Version 4) UUID or panics.
+//
+// The strength of the UUIDs is based on the strength of the crypto/rand
+// package.
+//
+// A note about uniqueness derived from from the UUID Wikipedia entry:
+//
+//  Randomly generated UUIDs have 122 random bits.  One's annual risk of being
+//  hit by a meteorite is estimated to be one chance in 17 billion, that
+//  means the probability is about 0.00000000006 (6 × 10−11),
+//  equivalent to the odds of creating a few tens of trillions of UUIDs in a
+//  year and having one duplicate.
+func NewRandom() UUID {
+	uuid := make([]byte, 16)
+	randomBits([]byte(uuid))
+	uuid[6] = (uuid[6] & 0x0f) | 0x40 // Version 4
+	uuid[8] = (uuid[8] & 0x3f) | 0x80 // Variant is 10
+	return uuid
+}
diff --git a/version4.go b/version4.go
deleted file mode 100644
index 465e19a..0000000
--- a/version4.go
+++ /dev/null
@@ -1,36 +0,0 @@
-// Copyright 2011 Google Inc.  All rights reserved.
-// Author: borman@google.com (Paul Borman)
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package uuid
-
-// Random returns a Random (Version 4) UUID or panics.
-//
-// The strength of the UUIDs is based on the strength of the crypto/rand
-// package.
-//
-// A note about uniqueness derived from from the UUID Wikipedia entry:
-//
-//  Randomly generated UUIDs have 122 random bits.  One's annual risk of being
-//  hit by a meteorite is estimated to be one chance in 17 billion, that
-//  means the probability is about 0.00000000006 (6 × 10−11),
-//  equivalent to the odds of creating a few tens of trillions of UUIDs in a
-//  year and having one duplicate.
-func NewRandom() UUID {
-	uuid := make([]byte, 16)
-	randomBits([]byte(uuid))
-	uuid[6] = (uuid[6] & 0x0f) | 0x40 // Version 4
-	uuid[8] = (uuid[8] & 0x3f) | 0x80 // Variant is 10
-	return uuid
-}