[0.21.0]

  * Updated to version 0.21 of spec.
  * Added latex renderer (#31). New exported function in API:
    `cmark_render_latex`. New source file: `src/latex.hs`.
  * Updates for new HTML block spec. Removed old `html_block_tag` scanner.
    Added new `html_block_start` and `html_block_start_7`, as well
    as `html_block_end_n` for n = 1-5. Rewrote block parser for new HTML
    block spec.
  * We no longer preprocess tabs to spaces before parsing.
    Instead, we keep track of both the byte offset and
    the (virtual) column as we parse block starts.
    This allows us to handle tabs without converting
    to spaces first.  Tabs are left as tabs in the output, as
    per the revised spec.
  * Removed utf8 validation by default.  We now replace null characters
    in the line splitting code.
  * Added `CMARK_OPT_VALIDATE_UTF8` option and command-line option
    `--validate-utf8`.  This option causes cmark to check for valid
    UTF-8, replacing invalid sequences with the replacement
    character, U+FFFD.  Previously this was done by default in
    connection with tab expansion, but we no longer do it by
    default with the new tab treatment.  (Many applications will
    know that the input is valid UTF-8, so validation will not
    be necessary.)
  * Added `CMARK_OPT_SAFE` option and `--safe` command-line flag.
    + Added `CMARK_OPT_SAFE`.  This option disables rendering of raw HTML
      and potentially dangerous links.
    + Added `--safe` option in command-line program.
    + Updated `cmark.3` man page.
    + Added `scan_dangerous_url` to scanners.
    + In HTML, suppress rendering of raw HTML and potentially dangerous
      links if `CMARK_OPT_SAFE`.  Dangerous URLs are those that begin
      with `javascript:`, `vbscript:`, `file:`, or `data:` (except for
      `image/png`, `image/gif`, `image/jpeg`, or `image/webp` mime types).
    + Added `api_test` for `OPT_CMARK_SAFE`.
    + Rewrote `README.md` on security.
  * Limit ordered list start to 9 digits, per spec.
  * Added width parameter to `render_man` (API change).
  * Extracted common renderer code from latex, man, and commonmark
    renderers into a separate module, `renderer.[ch]` (#63).  To write a
    renderer now, you only need to write a character escaping function
    and a node rendering function.  You pass these to `cmark_render`
    and it handles all the plumbing (including line wrapping) for you.
    So far this is an internal module, but we might consider adding
    it to the API in the future.
  * commonmark writer:  correctly handle email autolinks.
  * commonmark writer:  escape `!`.
  * Fixed soft breaks in commonmark renderer.
  * Fixed scanner for link url. re2c returns the longest match, so we
    were getting bad results with `[link](foo\(and\(bar\)\))`
    which it would parse as containing a bare `\` followed by
    an in-parens chunk ending with the final paren.
  * Allow non-initial hyphens in html tag names. This allows for
    custom tags, see jgm/CommonMark#239.
  * Updated `test/smart_punct.txt`.
  * Implemented new treatment of hyphens with `--smart`, converting
    sequences of hyphens to sequences of em and en dashes that contain no
    hyphens.
  * HTML renderer:  properly split info on first space char (see
    jgm/commonmark.js#54).
  * Changed version variables to functions (#60, Andrius Bentkus).
    This is easier to access using ffi, since some languages, like C#
    like to use only function interfaces for accessing library
    functionality.
  * `process_emphasis`: Fixed setting lower bound to potential openers.
    Renamed `potential_openers` -> `openers_bottom`.
    Renamed `start_delim` -> `stack_bottom`.
  * Added case for #59 to `pathological_test.py`.
  * Fixed emphasis/link parsing bug (#59).
  * Fixed off-by-one error in line splitting routine.
    This caused certain NULLs not to be replaced.
  * Don't rtrim in `subject_from_buffer`.  This gives bad results in
    parsing reference links, where we might have trailing blanks
    (`finalize` removes the bytes parsed as a reference definition;
    before this change, some blank bytes might remain on the line).
    + Added `column` and `first_nonspace_column` fields to `parser`.
    + Added utility function to advance the offset, computing
      the virtual column too.  Note that we don't need to deal with
      UTF-8 here at all.  Only ASCII occurs in block starts.
    + Significant performance improvement due to the fact that
      we're not doing UTF-8 validation.
  * Fixed entity lookup table.  The old one had many errors.
    The new one is derived from the list in the npm entities package.
    Since the sequences can now be longer (multi-code-point), we
    have bumped the length limit from 4 to 8, which also affects
    `houdini_html_u.c`.  An example of the kind of error that was fixed:
    `&ngE;` should be rendered as "≧̸" (U+02267 U+00338), but it was
    being rendered as "≧" (which is the same as `&gE;`).
  * Replace gperf-based entity lookup with binary tree lookup.
    The primary advantage is a big reduction in the size of
    the compiled library and executable (> 100K).
    There should be no measurable performance difference in
    normal documents.  I detected only a slight performance
    hit in a file containing 1,000,000 entities.
    + Removed `src/html_unescape.gperf` and `src/html_unescape.h`.
    + Added `src/entities.h` (generated by `tools/make_entities_h.py`).
    + Added binary tree lookup functions to `houdini_html_u.c`, and
      use the data in `src/entities.h`.
    * Renamed `entities.h` -> `entities.inc`, and
      `tools/make_entities_h.py` -> `tools/make_entitis_inc.py`.
  * Fixed cases like
    ```
    [ref]: url
    "title" ok
    ```
    Here we should parse the first line as a reference.
  * `inlines.c`:  Added utility functions to skip spaces and line endings.
  * Fixed backslashes in link destinations that are not part of escapes
    (jgm/commonmark#45).
  * `process_line`: Removed "add newline if line doesn't have one."
    This isn't actually needed.
  * Small logic fixes and a simplification in `process_emphasis`.
  * Added more pathological tests:
    + Many link closers with no openers.
    + Many link openers with no closers.
    + Many emph openers with no closers.
    + Many closers with no openers.
    + `"*a_ " * 20000`.
  * Fixed `process_emphasis` to handle new pathological cases.
    Now we have an array of pointers (`potential_openers`),
    keyed to the delim char.  When we've failed to match a potential opener
    prior to point X in the delimiter stack, we reset `potential_openers`
    for that opener type to X, and thus avoid having to look again through
    all the openers we've already rejected.
  * `process_inlines`:  remove closers from delim stack when possible.
    When they have no matching openers and cannot be openers themselves,
    we can safely remove them.  This helps with a performance case:
    `"a_ " * 20000` (jgm/commonmark.js#43).
  * Roll utf8proc_charlen into utf8proc_valid (Nick Wellnhofer).
    Speeds up "make bench" by another percent.
  * `spec_tests.py`: allow `→` for tab in HTML examples.
  * `normalize.py`:  don't collapse whitespace in pre contexts.
  * Use utf-8 aware re2c.
  * Makefile afl target:  removed `-m none`, added `CMARK_OPTS`.
  * README: added `make afl` instructions.
  * Limit generated generated `cmark.3` to 72 character line width.
  * Travis: switched to containerized build system.
  * Removed `debug.h`. (It uses GNU extensions, and we don't need it anyway.)
  * Removed sundown from benchmarks, because the reading was anomalous.
    sundown had an arbitrary 16MB limit on buffers, and the benchmark
    input exceeded that.  So who knows what we were actually testing?
    Added hoedown, sundown's successor, which is a better comparison.

[0.20.0]

  * Fixed bug in list item parsing when items indented >= 4 spaces (#52).
  * Don't allow link labels with no non-whitespace characters
    (jgm/CommonMark#322).
  * Fixed multiple issues with numeric entities (#33, Nick Wellnhofer).
  * Support CR and CRLF line endings (Ben Trask).
  * Added test for different line endings to `api_test`.
  * Allow NULL value in string setters (Nick Wellnhofer).  (NULL
    produces a 0-length string value.)  Internally, URL and
    title are now stored as `cmark_chunk` rather than `char *`.
  * Fixed memory leak in `cmark_consolidate_text_nodes` (#32).
  * Fixed `is_autolink` in the CommonMark renderer (#50).  Previously *any*
    link with an absolute URL was treated as an autolink.
  * Cope with broken `snprintf` on Windows (Nick Wellnhofer).  On Windows,
    `snprintf` returns -1 if the output was truncated. Fall back to
    Windows-specific `_scprintf`.
  * Switched length parameter on `cmark_markdown_to_html`,
    `cmark_parser_feed`, and `cmark_parse_document` from `int`
    to `size_t` (#53, Nick Wellnhofer).
  * Use a custom type `bufsize_t` for all string sizes and indices.
    This allows to switch to 64-bit string buffers by changing a single
    typedef and a macro definition (Nick Wellnhofer).
  * Hardened the `strbuf` code, checking for integer overflows and
    adding range checks (Nick Wellnhofer).
  * Removed unused function `cmark_strbuf_attach` (Nick Wellnhofer).
  * Fixed all implicit 64-bit to 32-bit conversions that
    `-Wshorten-64-to-32` warns about (Nick Wellnhofer).
  * Added helper function `cmark_strbuf_safe_strlen` that converts
    from `size_t` to `bufsize_t` and throws an error in case of
    an overflow (Nick Wellnhofer).
  * Abort on `strbuf` out of memory errors (Nick Wellnhofer).
    Previously such errors were not being trapped.  This involves
    some internal changes to the `buffer` library that do not affect
    the API.
  * Factored out `S_find_first_nonspace` in `S_proces_line`.
    Added fields `offset`, `first_nonspace`, `indent`, and `blank`
    to `cmark_parser` struct.  This just removes some repetition.
  * Added Racket Racket (5.3+) wrapper (Eli Barzilay).
  * Removed `-pg` from Debug build flags (#47).
  * Added Ubsan build target, to check for undefined behavior.
  * Improved `make leakcheck`.  We now return an error status if anything
    in the loop fails.  We now check `--smart` and `--normalize` options.
  * Removed `wrapper3.py`, made `wrapper.py` work with python 2 and 3.
    Also improved the wrapper to work with Windows, and to use smart
    punctuation (as an example).
  * In `wrapper.rb`, added argument for options.
  * Revised luajit wrapper.
  * Added build status badges to README.md.
  * Added links to go, perl, ruby, R, and Haskell bindings to README.md.

[0.19.0]

  * Fixed `_` emphasis parsing to conform to spec (jgm/CommonMark#317).
  * Updated `spec.txt`.
  * Compile static library with `-DCMARK_STATIC_DEFINE` (Nick Wellnhofer).
  * Suppress warnings about Windows runtime library files (Nick Wellnhofer).
    Visual Studio Express editions do not include the redistributable files.
    Set `CMAKE_INSTALL_SYSTEM_RUNTIME_LIBS_NO_WARNINGS` to suppress warnings.
  * Added appyeyor: Windows continuous integration (`appveyor.yml`).
  * Use `os.path.join` in `test/cmark.py` for proper cross-platform paths.
  * Fixed `Makefile.nmake`.
  * Improved `make afl`:  added `test/afl_dictionary`, increased timeout
    for hangs.
  * Improved README with a description of the library's strengths.
  * Pass-through Unicode non-characters (Nick Wellnhofer).
    Despite their name, Unicode non-characters are valid code points. They
    should be passed through by a library like libcmark.
  * Check return status of `utf8proc_iterate` (#27).

[0.18.3]

  * Include patch level in soname (Nick Wellnhofer). Minor version is
    tied to spec version, so this allows breaking the ABI between spec
    releases.
  * Install compiler-provided system runtime libraries (Changjiang Yang).
  * Use `strbuf_printf` instead of `snprintf`. `snprintf` is not
    available on some platforms (Visual Studio 2013 and earlier).
  * Fixed memory access bug: "invalid read of size 1" on input `[link](<>)`.

[0.18.2]

  * Added commonmark renderer: `cmark_render_commonmark`. In addition
    to options, this takes a `width` parameter.  A value of 0 disables
    wrapping; a positive value wraps the document to the specified
    width.  Note that width is automatically set to 0 if the
    `CMARK_OPT_HARDBREAKS` option is set.
  * The `cmark` executable now allows `-t commonmark` for output as
    CommonMark.  A `--width` option has been added to specify wrapping
    width.
  * Added `roundtrip_test` Makefile target.  This runs all the spec
    through the commonmark renderer, and then through the commonmark
    parser, and compares normalized HTML to the test.  All tests pass
    with the current parser and renderer, giving us some confidence that
    the commonmark renderer is sufficiently robust.  Eventually this
    should be pythonized and put in the cmake test routine.
  * Removed an unnecessary check in `blocks.c`.  By the time we check
    for a list start, we've already checked for a horizontal rule, so
    we don't need to repeat that check here.  Thanks to Robin Stocker for
    pointing out a similar redundancy in commonmark.js.
  * Fixed bug in `cmark_strbuf_unescape` (`buffer.c`).  The old function
    gave incorrect results on input like `\\*`, since the next backslash
    would be treated as escaping the `*` instead of being escaped itself.
  * `scanners.re`:  added `_scan_scheme`, `scan_scheme`, used in the
    commonmark renderer.
  * Check for `CMAKE_C_COMPILER` (not `CC_COMPILER`) when setting C flags.
  * Update code examples in documentation, adding new parser option
    argument, and using `CMARK_OPT_DEFAULT` (Nick Wellnhofer).
  * Added options parameter to `cmark_markdown_to_html`.
  * Removed obsolete reference to `CMARK_NODE_LINK_LABEL`.
  * `make leakcheck` now checks all output formats.
  * `test/cmark.py`:  set default options for `markdown_to_html`.
  * Warn about buggy re2c versions (Nick Wellnhofer).

[0.18.1]

  * Build static version of library in default build (#11).
  * `cmark.h`:  Add missing argument to `cmark_parser_new` (#12).

[0.18]

  * Switch to 2-clause BSD license, with agreement of contributors.
  * Added Profile build type, `make prof` target.
  * Fixed autolink scanner to conform to the spec. Backslash escapes
    not allowed in autolinks.
  * Don't rely on strnlen being available (Nick Wellnhofer).
  * Updated scanners for new whitespace definition.
  * Added `CMARK_OPT_SMART` and `--smart` option, `smart.c`, `smart.h`.
  * Added test for `--smart` option.
  * Fixed segfault with --normalize (closes #7).
  * Moved normalization step from XML renderer to `cmark_parser_finish`.
  * Added options parameter to `cmark_parse_document`, `cmark_parse_file`.
  * Fixed man renderer's escaping for unicode characters.
  * Don't require python3 to make `cmark.3` man page.
  * Use ASCII escapes for punctuation characters for portability.
  * Made `options` an int rather than a long, for consistency.
  * Packed `cmark_node` struct to fit into 128 bytes.
    This gives a small performance boost and lowers memory usage.
  * Repacked `delimiter` struct to avoid hole.
  * Fixed use-after-free bug, which arose when a paragraph containing
    only reference links and blank space was finalized (#9).
    Avoid using `parser->current` in the loop that creates new
    blocks, since `finalize` in `add_child` may have removed
    the current parser (if it contains only reference definitions).
    This isn't a great solution; in the long run we need to rewrite
    to make the logic clearer and to make it harder to make
    mistakes like this one.
  * Added 'Asan' build type. `make asan` will link against ASan; the
    resulting executable will do checks for memory access issues.
    Thanks @JordanMilne for the suggestion.
  * Add Makefile target to fuzz with AFL (Nick Wellnhofer)
    The variable `$AFL_PATH` must point to the directory containing the AFL
    binaries. It can be set as an environment variable or passed to make on
    the command line.

[0.17]

  * Stripped out all JavaScript related code and documentation, moving
    it to a separate repository (<https://github.com/jgm/commonmark.js>).
  * Improved Makefile targets, so that `cmake` is run again only when
    necessary (Nick Wellnhofer).
  * Added `INSTALL_PREFIX` to the Makefile, allowing installation to a
    location other than `/usr/local` without invoking `cmake`
    manually (Nick Wellnhofer).
  * `make test` now guarantees that the project will
    be rebuilt before tests are run (Nick Wellnhofer).
  * Prohibited overriding of some Makefile variables (Nick Wellnhofer).
  * Provide version number and string, both as macros
    (`CMARK_VERSION`, `CMARK_VERSION_STRING`) and as symbols
    (`cmark_version`, `cmark_version_string`) (Nick Wellnhofer).  All of
    these come from `cmark_version.h`, which is constructed from a
    template `cmark_version.h.in` and data in `CMakeLists.txt`.
  * Avoid calling `free` on null pointer.
  * Added an accessor for an iterator's root node (`cmark_iter_get_root`).
  * Added user data field for nodes (Nick Wellnhofer).  This is
    intended mainly for use in bindings for dynamic languages, where
    it could store a pointer to a target language object (#287).  But
    it can be used for anything.
  * Man renderer:  properly escape multiline strings.
  * Added assertion to raise error if finalize is called on a closed block.
  * Implemented the new spec rule for emphasis and strong emphasis with `_`.
  * Moved the check for fence-close with the other checks for end-of-block.
  * Fixed a bug with loose list detection with items containings
    fenced code blocks (#285).
  * Removed recursive algorithm in `ends_with_blank_line` (#286).
  * Minor code reformatting: renamed parameters.

[0.16]

  * Added xml renderer (XML representation of the CommonMark AST,
    which is described in `CommonMark.dtd`).
  * Reduced size of gperf entity table (Nick Wellnhofer).
  * Reworked iterators to allow deletion of nodes during iteration
    (Nick Wellnhofer).
  * Optimized `S_is_leaf`.
  * Added `cmark_iter_reset` to iterator API.
  * Added `cmark_consolidate_text_nodes` to API to combine adjacent
    text nodes.
  * Added `CMARK_OPT_NORMALIZE` to options (this combines adjacent
    text nodes).
  * Added `--normalize` option to command-line program.
  * Improved regex for HTML comments in inline parsing.
  * Python is no longer required for a basic build from the
    repository.