cmark

• Update to 0.31.2 spec.txt.

• Treat unicode Symbols like Punctuation, as per the 0.31 spec.

• Add a new function to utf8.h:
  int cmark_utf8proc_is_punctuation_or_symbol(int32_t uc).
  The old cmark_utf8proc_is_punctuation has been kept for
  now, but it is no longer used.

• Add new exported function cmark_parser_new_with_mem_into_root
  (API change) (John Ericson).

• Avoid repeated language- in info string (commonmark/commonmark.js#277).

• Fix quadratic behavior in S_insert_emph (Nick Wellnhofer).
  Fixes part of GHSA-66g8-4hjf-77xh.

• Fix quadratic behavior in check_open_blocks (Nick Wellnhofer).
  Fixes part of GHSA-66g8-4hjf-77xh.

• Track underscore bottom separately mod 3, like asterisk (Michael
  Howell). This was already implemented correctly for asterisks,
  but not for underscore.

• Use fwrite instead of printf to print results in main (#523).
  This avoids a massive slowdown in MSYS2.

• commonmark writer: less aggressive escaping for ! (#131).

• Update libFuzzer build (Nick Wellnhofer):

  • Move fuzzing files into their own directory.
  • Use libFuzzer the modern way by compiling and linking with
    -fsanitize=fuzzer(-no-link) without requiring LIB_FUZZER_PATH.
  • Update the libFuzzer rule in Makefile and the README.md.

• CMake build changes (Saleem Abdulrasool).

  • Inline multiple variables in CMake, following CMake recommendations.
  • Simplify the version computation.
  • Remove the CMARK_STATIC and CMARK_SHARED options as one of the two
    must be enabled always as the cmark executable depends on the library.
    Instead of having a custom flag to discern between the
    library type, use the native CMake option BUILD_SHARED_LIBS,
    allowing the user to control which library to build. This matches
    CMake recommendations to only build a single copy of the library.
  • Introduce an author warning for the use of CMARK_SHARED and
    CMARK_STATIC to redirect the author of the dependent package to
    BUILD_SHARED_LIBS.
  • Permit incremental linking on Windows. Although incremental linking
    does introduce padding in the binary for incremental links, that
    should not matter for release mode builds in theory as /OPT:REF
    and /OPT:ICF will trigger full links, which is the default in
    release mode.
  • Hoist the CMake module inclusion to the top level.
  • Minor tweaks for speeding up the configure phase.
    Restructure the file layout to place the custom modules into the
    cmake/modules directory that is the common layout for CMake based
    projects.
  • Squelch C4232 warnings on MSVC builds.
  • Remove check for __builtin_expect. Use __has_builtin to check
    at compile time if the feature is supported.
    This macro is supported by both clang and GCC (as of 10).
    In the case that the compiler in use is not new enough, we still
    provide the fallback so that the code will compile but without the
    additional hints for the branch probability. config.h has been
    removed from the code base as it is no longer needed.
  • Remove /TP usage on MSVC and replace CMARK_INLINE with inline.
    These were workarounds for pre-VS2015 compilers, which are no longer
    supported.
  • Hoist the C visibility settings to top level
  • Clean up C4267 warnings on MSVC builds.
  • Remove some compiler compatibility checks that are no longer
    needed because VS 2013 is no longer supported (#498).
  • Adjust the policy to silence warnings on MSVC builds
    CMake 3.15+ remove /W3 from the language flags under MSVC with
    CMP0092. Set the policy to new to avoid the D9025 warning.
  • Reflow some text to match CMake documentation style
  • Use generator expression for path computation.
  • Use CMake to propagate CMARK_STATIC_DEFINE.
  • Clean up an obsoleted variable (NFC).
  • Hoist the policy settings. Policy settings may impact how
    project functions. They should be set immediately after
    cmake_minimum_required (which implicitly sets policies).
    Use the POLICY check to see if a policy is defined rather
    than using a version check.
  • Replace CMARK_TESTS with CMake sanctioned BUILD_TESTING.
  • Correct typo and adjust command invocation. Use the proper
    generator expression for the python interpreter and adjust
    a typo in the component name.
  • Add an upgrade path for newer CMake.
    CMake 3.12 deprecated FindPythonInterp, and with CMake 3.27, were
    obsoleted with CMP0148. Add a version check and switch to the new
    behaviour to allow building with newer releases.

• Fix regex syntax warnings in pathological_tests.py (Nick Wellnhofer).

• test/cmark.py: avoid star imports (Jakub Wilk).

• spec_tests.py: Add option to generate fuzz corpus (Nick Wellnhofer).
  Add an option --fuzz-corpus that writes the test cases to separate
  files including the options header, so they can be used as seed corpus
  for fuzz testing.

• Fix some cmark.3 man rendering issues so we can do a clean regen
  (John Ericson).

• Update Windows compilation instructions (Pomax, #525).

• Fix quadratic complexity bug with repeated ![[]().
  Resolves CVE-2023-22486. Add new pathological test. (John MacFarlane)

• Allow declarations with no space, as per spec (#456, John MacFarlane).

• Set enumi* counter correctly in LaTeX output (#451, John MacFarlane).

• Allow <!DOCTYPE to be case-insensitive. (This conforms to the
  existing spec.) (John MacFarlane)

• Fixed HTML comment scanning. Need to handle this case: <!--> and -->.
  Since the scanner finds the longest match, we had to
  move some of the logic outside of the scanner. (John MacFarlane)

• Fix quadratic parsing issue with repeated <!-- (this was not
  introduced by the previous fix, and not in a released version of cmark).
  Resolves CVE-2023-22484. Add new pathological test. (John MacFarlane)

• Update HTML comment scanner to accord with commonmark/commonmark-spec#713
  (John MacFarlane).

• Pathological tests: half the number of repetitions, and the timeout.
  This reduces the time needed for the pathological tests.
  (John MacFarlane)

• Shrink struct cmark_node (#446). The internal_offset member is
  only used for headings and can be moved to struct cmark_heading.
  This reduces the size of struct cmark_node from 112 to 104 bytes on
  64-bit systems. (Nick Wellnhofer)

• Add -Wstrict-prototypes and fix offending functions. (Nick
  Wellnhofer, Dan Cîrnaț)

• Fix quadratic behavior involving get_containing_block (#431).
  Instead of searching for the containing block, update the tight list
  status when entering a child of a list item or exiting a list.
  (Nick Wellnhofer)

• Fix pathological_tests.py (Nick Wellnhofer):

  • Use a multiprocessing.Queue to actually get results from spawned
    tests processes.
  • Fix the allowed_failures test.
  • Truncate actual output when printed.
  • Prepare for testing pathological behavior of the Commonmark renderer.

• Fix source position bug with backticks (kyle).

• Fix parsing of emphasis before links (#424, Nick Wellnhofer).
  Fixes a regression introduced with commit ed0a4bf.

• Update to Unicode 14.0 (data-man).

• Add ~ to safe href character set (#394, frogtile).

• Update CMakeLists.txt (Saleem Abdulrasool). Bump the minimum required
  CMake to 3.7. Imperatively define output name for static library.

• Fix install paths in libcmark.pc (Sebastián Mancilla).
  CMAKE_INSTALL_<dir> can be relative or absolute path, so it is wrong to
  prefix CMAKE_INSTALL_PREFIX because if CMAKE_INSTALL_<dir> is set to an
  absolute path it will result in a malformed path with two absolute paths
  joined together. Instead, use CMAKE_INSTALL_FULL_<dir> from
  GNUInstallDirs.

• Properly indent block-level contents of list items in man (#258).
  This handles nested lists as well as items with multiple paragraphs.
  The change requires addition of a new field block_number_in_list_item
  to cmark_renderer, but this does not change the public API.
• Fix quadratic behavior when parsing emphasis (#389, Nick
  Wellnhofer). Delimiters can be deleted, so store delimiter positions
  instead of pointers in openers_bottom. Besides causing undefined
  behavior when reading a dangling pointer, this could also result
  in quadratic behavior when parsing emphasis.
• Fix quadratic behavior when parsing smart quotes (#388, Nick Wellnhofer).
  Remove matching smart quote delimiters. Otherwise, the same opener
  could be found over and over, preventing the openers_bottom
  optimization from kicking in and leading to quadratic behavior when
  processing lots of quotes.
• Modify CMake configuration so that the project can be built with
  older versions of CMake (#384, Saleem Abdulrasool). (In 0.30.0,
  some features were used that require CMake >= 3.3.) The cost of this
  backwards compatibility is that developers must now explicitly invoke
  cmark_add_compile_options when a new compilation target is added.
• Remove a comma at the end of an enumerator list, which was flagged
  by clang as a C++11 extension.
• make_man_page.py: use absolute path with CDLL. This avoids the error
  "file system relative paths not allowed in hardened programs."
• Include cmark version in cmark(3) man page (instead of LOCAL).

• Use official 0.30 spec.txt.
• Add cmark_get_default_mem_allocator() (#330). API change: this
  adds a new exported function in cmark.h.
• Fix #383. An optimization we used for emphasis parsing was
  too aggressive, causing us to miss some emphasis that was legal
  according to the spec. We fix this by indexing the openers_bottom
  table not just by the type of delimiter and the length of the
  closing delimiter mod 3, but by whether the closing delimiter
  can also be an opener. (The algorithm for determining emphasis
  matching depends on all these factors.) Add regression test.
• Fix quadratic behavior with inline HTML (#299, Nick Wellnhofer).
  Repeated starting sequences like <?, <!DECL or <![CDATA[ could
  lead to quadratic behavior if no matching ending sequence was found.
  Separate the inline HTML scanners. Remember if scanning the whole input
  for a specific ending sequence failed and skip subsequent scans.
• Speed up hierarchy check in tree manipulation API (Nick Wellnhofer).
  Skip hierarchy check in the common case that the inserted child has
  no children.
• Fix quadratic behavior when parsing inlines (#373, Nick Wellnhofer).
  The inline parsing code would call cmark_node_append_child to append
  nodes. This public function has a sanity check which is linear in the
  depth of the tree. Repeated calls could show quadratic behavior in
  degenerate trees. Use a special function to append nodes without this
  check. (Issue found by OSS-Fuzz.)
• Replace invalid characters in XML output (#365, Nick wellnhofer).
  Control characters, U+FFFE and U+FFFF aren't allowed in XML 1.0, so
  replace them with U+FFFD (replacement character). This doesn't solve
  the problem how to roundtrip these characters, but at least we don't
  produce invalid XML.
• Avoid quadratic output growth with reference links (#354, Nick Wellnhofer).
  Keep track of the number bytes added through expansion of reference
  links and limit the total to the size of the input document. Always
  allow a minimum of 100KB. Unfortunately, cmark has no error handling,
  so all we can do is to stop expanding reference links without returning
  an error. This should never be an issue in practice though. The 100KB
  minimum alone should cover all real-world cases.
• Fix issue with type-7 HTML blocks interrupting paragraphs
  (see commonmark/commonmark.js#213).
• Treat textarea like script, style, pre (type 1 HTML block),
  in accordance with spec change.
• Define whitespace per spec (Asherah Conor).
• Add MAX_INDENT for xml (#355). Otherwise we can get quadratic
  increase in size with deeply nested structures.
• Fix handling of empty strings when creating XML/HTML output
  (Steffen Kieß).
• Commonmark renderer: always use fences for code (#317).
  This solves problems with adjacent code blocks being merged.
• Improve rendering of commonmark code spans with spaces (#316).
• Cleaner approach to max digits for numeric entities.
  This modifies unescaping in houdini_html_u.c rather than
  the entity handling in inlines.c. Unlike the other,
  this approach works also in e.g. link titles.
• Fix entity parser (and api test) to respect length limit on
  numeric entities.
• Don't allow link destinations with unbalanced unescaped parentheses.
  See commonmark/commonmark.js#177.
• print_usage(): Minor grammar fix, swap two words (#305, Øyvind A. Holm).
• Don't call memcpy with NULL as first parameter.
  This is illegal according to the C standard, sec. 7.1.4.
  See https://www.imperialviolet.org/2016/06/26/nonnull.html.
• Add needed include in blocks.c.
• Fix unnecessary variable assignment.
• Skip UTF-8 BOM if present at beginning of buffer (#334).
• Fix URL check in is_autolink (Nick Wellnhofer). In a recent commit,
  the check was changed to strcmp, but we really have to use strncmp.
• Fix null pointer deref in is_autolink (Nick Wellnhofer).
  Introduced by a recent commit. Found by OSS-Fuzz.
• Rearrange struct cmark_node (Nick Wellnhofer). Introduce multi-purpose
  data/len members in struct cmark_node. This is mainly used to store
  literal text for inlines, code and HTML blocks.
  Move the content strbuf for blocks from cmark_node to cmark_parser.
  When finalizing nodes that allow inlines (paragraphs and headings),
  detach the strbuf and store the block content in the node's data/len
  members. Free the block content after processing inlines.
  Reduces size of struct cmark_node by 8 bytes.
• Improve packing of struct cmark_list (Nick Wellnhofer).
• Use C string instead of chunk in a number of contexts (Nick Wellnhofer,
  #309). The node struct never references memory of other nodes now.
  Node accessors don't have to check for delayed creation of C strings,
  so parsing and iterating all literals using the public API should
  actually be faster than before. These changes also reduce the size
  of struct cmark_node.
• Add casts for MSVC10 (from kivikakk in cmark-cfm).
• commonmark renderer: better escaping in smart mode. When
  CMARK_OPT_SMART is enabled, we escape literal -, ., and quote
  characters when needed to avoid their being "smartified."
• Add options field to cmark_renderer.
• commonmark.c - use size_t instead of int.
• Include string.h in cmark-fuzz.c.
• Fix #220 (hash collisions for references) (Vicent Marti via cmark-gfm).
  Reimplemented reference storage as follows:
  1. New references are always inserted at the end of a linked list. This
     is an O(1) operation, and does not check whether an existing (duplicate)
     reference with the same label already exists in the document.
  2. Upon the first call to cmark_reference_lookup (when it is expected
     that no further references will be added to the reference map), the
     linked list of references is written into a fixed-size array.
  3. The fixed size array can then be efficiently sorted in-place in O(n
     log n). This operation only happens once. We perform this sort in a
     stable manner to ensure that the earliest link reference in the
     document always has preference, as the spec dictates. To accomplish
     this, every reference is tagged with a generation number when initially
     inserted in the linked list.
  4. The sorted array is then compacted in O(n). Since it was sorted in a
     stable way, the first reference for each label is preserved and the
     duplicates are removed, matching the spec.
  5. We can now simply perform a binary search for the current
     cmark_reference_lookup query in O(log n). Any further lookup calls
     will also be O(log n), since the sorted references table only needs to
     be generated once.
     The resulting implementation is notably simple (as it uses standard
     library builtins qsort and bsearch), whilst performing better than
     the fixed size hash table in documents that have a high number of
     references and never becoming pathological regardless of the input.
• Comment out unused function cmark_strbuf_cstr in buffer.h.
• Re-add --safe command-line option as a no-op (#344), for backwards
  compatibility.
• Update to Unicode 13.0
• Generate and install cmake-config file (Reinhold Gschweicher).
  Add full cmake support. The project can either be used with
  add_subdirectory or be installed into the system (or some other
  directory) and be found with find_package(cmark). In both cases the
  cmake target cmark::cmark and/or cmark::cmark_static is all that
  is needed to be linked. Previously the cmarkConfig.cmake file
  was generated, but not installed. As additional bonus of generation
  by cmake we get a generated cmake-config-version.cmake file for
  find_package() to search for the same major version.
  The generated config file is position independent, allowing the
  installed directory to be copied or moved and still work.
  The following four files are generated and installed:
  lib/cmake/cmark/cmark-config.cmake,
  lib/cmake/cmark/cmark-config-version.cmake,
  lib/cmake/cmark/cmark-targets.cmake,
  lib/cmake/cmark/cmark-targets-release.cmake.
• Adjust the MinGW paths for MinGW64 (Daniil Baturin).
• Fix CMake generator expression checking for MSVC (Nick Wellnhofer).
• Fix -Wconst-qual warning (Saleem Abdulrasool). This enables building
  with /Zc:strictString with MSVC as well.
• Improve and modernize cmake build (Saleem Abdulrasool).
  • Build: add exports targets for build tree usage (#307).
  • Uuse target properties for include paths.
  • Remove the unnecessary execute permission on CMakeLists.txt.
  • Reduce property computation in CMake.
  • Use CMAKE_INCLUDE_CURRENT_DIRECTORY.
  • Improve man page installation.
  • Only include GNUInstallDirs once.
  • Replace add_compile_definitions with add_compile_options
    since the former was introduced in 3.12 (#321).
  • Cleanup CMake (#319).
  • Inline a variable.
  • Use LINKER_LANGUAGE property for C++ runtime.
  • Use CMake to control C standard.
  • Use the correct variable.
  • Loosen the compiler check
  • Hoist shared flags to top-level CMakeLists
  • Remove duplicated flags.
  • Use add_compile_options rather than modify CMAKE_C_FLAGS.
  • Hoist sanitizer flags to global state.
  • Hoist -fvisibilty flags to top-level.
  • Hoist the debug flag handling.
  • Hoist the profile flag handling.
  • Remove incorrect variable handling.
  • Remove unused CMake includes.
• Remove "-rdynamic" flag for static builds (#300, Eric Pruitt).
• Fixed installation on other than Ubuntu GNU/Linux distributions
  (Vitaly Zaitsev).
• Link executable with static or shared library (Nick Wellnhofer).
  If CMARK_STATIC is on (default), link the executable with the static
  library. This produces exactly the same result as compiling the library
  sources again and linking with the object files.
  If CMARK_STATIC is off, link the executable with the shared library.
  This wasn't supported before and should be the preferred way to
  package cmark on Linux distros.
  Building only a shared library and a statically linked executable
  isn't supported anymore but this doesn't seem useful.
• Reintroduce version check for MSVC /TP flag (Nick Wellnhofer).
  The flag is only required for old MSVC versions.
• normalize.py: use html.escape instead of cgi.escape (#313).
• Fix pathological_tests.py on Windows (Nick Wellnhofer).
  When using multiprocessing on Windows, the main program must be
  guarded with a __name__ check.
• Remove useless __name__ check in test scripts (Nick Wellnhofer).
• Add CIFuzz (Leo Neat).
• cmark.1 - Document --unsafe instead of --safe (#332).
• cmark.1: remove docs for --normalize which no longer exists (#332).
• Add lint target to Makefile.
• Add uninstall target to Makefile.
• Update benchmarks (#338).
• Fix typo in documentation (Tim Gates).
• Increase timeout for pathological tests to avoid CI failure.
• Update the Racket wrapper with the safe -> unsafe flag change (Eli
  Barzilay).

[0.29.0]

• Update spec to 0.29.
• Make rendering safe by default (#239, #273). Adds CMARK_OPT_UNSAFE and make CMARK_OPT_SAFE a no-op (for API compatibility). The new default behavior is to suppress raw HTML and potentially dangerous links. The CMARK_OPT_UNSAFE option has to be set explicitly to prevent this. NOTE: This change will require modifications in bindings for cmark and in most libraries and programs that use cmark. Borrows heavily from @kivikakk's patch in github/cmark-gfm#123.
• Add sourcepos info for inlines (Yuki Izumi).
• Disallow more than 32 nested balanced parens in a link (Yuki Izumi).
• Resolve link references before creating setext header. A setext header line after a link reference should not create a header, according to the spec.
• commonmark renderer: improve escaping. URL-escape special characters when escape mode is URL, and not otherwise. Entity-escape control characters (< 0x20) in non-literal escape modes.
• render: only emit actual newline when escape mode is LITERAL. For markdown content, e.g., in other contexts we want some kind of escaping, not a literal newline.
• Update code span normalization to conform with spec change.
• Allow empty <> link destination in reference link.
• Remove leftover includes of memory.h (#290).
• A link destination can't start with < unless it is an angle-bracket link that also ends with > (#289). (If your URL really starts with <, URL-escape it.)
• Allow internal delimiter runs to match if both have lengths that are multiples of 3. See commonmark/commonmark#528.
• Include references.h in parser.h (#287).
• Fix [link](<foo\>).
• Use hand-rolled scanner for thematic break (see #284). Keep track of the last position where a thematic break failed to match on a line, to avoid rescanning unnecessarily.
• Rename ends_with_blank_line with S_ prefix.
• Add CMARK_NODE__LAST_LINE_CHECKED flag (#284). Use this to avoid unnecessary recursion in ends_with_blank_line.
• In ends_with_blank_line, call S_set_last_line_blank to avoid unnecessary repetition (#284). Once we settle whether a list item ends in a blank line, we don't need to revisit this in considering parent list items.
• Disallow unescaped ( in parenthesized link title.
• Copy line/col info straight from opener/closer (Ashe Connor). We can't rely on anything in subj since it's been modified while parsing the subject and could represent line info from a future line. This is simple and works.
• render.c: reset last_breakable after cr. Fixes jgm/pandoc#5033.
• Fix a typo in houdini_href_e.c (Felix Yan).
• commonmark writer: use ~~~ fences if info string contains backtick. This is needed for round-trip tests.
• Update scanners for new info string rules.
• Add XSLT stylesheet to convert cmark XML back to Commonmark (Nick Wellnhofer, #264). Initial version of an XSLT stylesheet that converts the XML format produced by cmark -t xml back to Commonmark.
• Check for whitespace before reference title (#263).
• Bump CMake to version 3 (Jonathan Müller).
• Build: Remove deprecated call to add_compiler_export_flags() (Jonathan Müller). It is deprecated in CMake 3.0, the replacement is to set the CXX_VISIBILITY_PRESET (or in our case C_VISIBILITY_PRESET) and VISIBILITY_INLINES_HIDDEN properties of the target. We're already setting them by setting the CMake variables anyway, so the call can be removed.
• Build: only attempt to install MSVC system libraries on Windows (Saleem Abdulrasool). Newer versions of CMake attempt to query the system for information about the VS 2017 installation. Unfortunately, this query fails on non-Windows systems when cross-compiling: cmake_host_system_information does not recognize <key> VS_15_DIR. CMake will not find these system libraries on non-Windows hosts anyways, and we were silencing the warnings, so simply omit the installation when cross-compiling to Windows.
• Simplify code normalization, in line with spec change.
• Implement code span spec changes. These affect both parsing and writing commonmark.
• Add link parsing corner cases to regressions (Ashe Connor).
• Add xml:space="preserve" in XML output when appropriate (Nguyễn Thái Ngọc Duy). (For text, code, code_block, html_inline and html_block tags.)
• Removed meta from list of block tags. Added regression test. See commonmark/CommonMark#527.
• entity_tests.py - omit noisy success output.
• pathological_tests.py: make tests run faster. Commented out the (already ignored) "many references" test, which times out. Reduced the iterations for a couple other tests.
• pathological_tests.py: added test for deeply nested lists.
• Optimize S_find_first_nonspace. We were needlessly redoing things we'd already done. Now we skip the work if the first nonspace is greater than the current offset. This fixes pathological slowdown with deeply nested lists (#255). For N = 3000, the time goes from over 17s to about 0.7s. Thanks to Martin Mitas for diagnosing the problem.
• Allow spaces in link destination delimited with pointy brackets.
• Adjust max length of decimal/numeric entities. See commonmark/CommonMark#487.
• Fix inline raw HTML parsing. This fixes a recently added failing spec test case. Previously spaces were being allowed in unquoted attribute values; no we forbid them.
• Don't allow list markers to be indented >= 4 spaces. See commonmark/CommonMark#497.
• Check for empty buffer when rendering (Phil Turnbull). For empty documents, ->size is zero so renderer.buffer->ptr[renderer.buffer->size - 1] will cause an out-of-bounds read. Empty buffers always point to the global cmark_strbuf__initbuf buffer so we read cmark_strbuf__initbuf[-1].
• Also run API tests with CMARK_SHARED=OFF (Nick Wellnhofer).
• Rename roundtrip and entity tests (Nick Wellnhofer). Rename the tests to reflect that they use the library, not the executable.
• Generate export header for static-only build (#247, Nick Wellnhofer).
• Fuzz width parameter too (Phil Turnbull). Allow the width parameter to be generated too so we get better fuzz-coverage.
• Don't discard empty fuzz test-cases (Phil Turnbull). We currently discard fuzz test-cases that are empty but empty inputs are valid markdown. This improves the fuzzing coverage slightly.
• Fixed exit code for pathological tests.
• Add allowed failures to pathological_tests.py. This allows us to include tests that we don't yet know how to pass.
• Add timeout to pathological_tests.py. Tests must complete in 8 seconds or are errors.
• Add more pathological tests (Martin Mitas). These tests target the issues #214, #218, #220.
• Use pledge(2) on OpenBSD (Ashe Connor).
• Update the Racket wrapper (Eli Barzilay).
• Makefile: For afl target, don't build tests.

• Include GNUInstallDirs in src/CMakeLists.txt (Nick Wellnhofer, #240).
  This fixes build problems on some cmake versions (#241).

• Fixed regression in install dest for static library (#238).
  Due to a mistake, 0.28.1 installed libcmark.a into include/.

• --smart: open quote can never occur right after ] or ) (#227).
• Fix quadratic behavior in finalize (Vicent Marti).
• Don't use CMAKE_INSTALL_LIBDIR to create libcmark.pc (#236). This wasn't getting set in processing libcmark.pc.in, and we were getting the wrong entry in libcmark.pc. The new approach sets an internal libdir variable to lib${LIB_SUFFIX}. This variable is used both to set the install destination and in the libcmark.pc.in template.
• Update README.md, replace make astyle with make format (Nguyễn Thái Ngọc Duy).

• Update spec.

• Use unsigned integer when shifting (Phil Turnbull).
  Avoids a UBSAN warning which can be triggered when handling a
  long sequence of backticks.

• Avoid memcpy'ing NULL pointers (Phil Turnbull).
  Avoids a UBSAN warning when link title is empty string.
  The length of the memcpy is zero so the NULL pointer is not
  dereferenced but it is still undefined behaviour.

• DeMorgan simplification of some tests in emphasis parser.
  This also brings the code into closer alignment with the wording
  of the spec (see jgm/CommonMark#467).

• Fixed undefined shift in commonmark writer (#211).
  Found by google/oss-fuzz:
  https://oss-fuzz.com/v2/testcase-detail/4686992824598528.

• latex writer: fix memory overflow (#210).
  We got an array overflow in enumerated lists nested more than
  10 deep with start number =/= 1.
  This commit also ensures that we don't try to set enum_ counters
  that aren't defined by LaTeX (generally up to enumv).
  Found by google/oss-fuzz:
  https://oss-fuzz.com/v2/testcase-detail/5546760854306816.

• Check for NULL pointer in get_link_type (Phil Turnbull).
  echo '[](xx:)' | ./build/src/cmark -t latex gave a
  segfault.

• Move fuzzing dictionary into single file (Phil Turnbull).
  This allows AFL and libFuzzer to use the same dictionary

• Reset bytes after UTF8 proc (Yuki Izumi, #206).

• Don't scan past an EOL (Yuki Izumi).
  The existing negated character classes ([^…]) are careful to
  always include \x00 in the characters excluded, but these .
  catch-alls can scan right past the terminating NUL placed
  at the end of the buffer by _scan_at. As such, buffer
  overruns can occur. Also, don't scan past a newline in HTML
  block end scanners.

• Document cases where get_ functions return NULL (#155).
  E.g. cmark_node_get_url on a non-link or image.

• Properly handle backslashes in link destinations (#192).
  Only ascii punctuation characters are escapable, per the spec.

• Fixed cmark_node_get_list_start to return 0 for bullet lists,
  as documented (#202).

• Use CMARK_NO_DELIM for bullet lists (#201).

• Fixed code for freeing delimiter stack (#189).

• Removed abort outside of conditional (typo).

• Removed coercion in error message when aborting from buffer.

• Print message to stderr when we abort due to memory demands (#188).

• libcmark.pc: use CMAKE_INSTALL_LIBDIR (#185, Jens Petersen).
  Needed for multilib distros like Fedora.

• Fixed buffer overflow error in S_parser_feed (#184).
  The overflow could occur in the following condition:
  the buffer ends with \r and the next memory address
  contains \n.

• Update emphasis parsing for spec change.
  Strong now goes inside Emph rather than the reverse,
  when both scopes are possible. The code is much simpler.
  This also avoids a spec inconsistency that cmark had previously:
  ***hi*** became Strong (Emph "hi")) but
  ***hi**** became Emph (Strong "hi")) "*"

• Fixes for the LaTeX renderer (#182, Doeme)

  • Don't double-output the link in latex-rendering.
  • Prevent ligatures in dashes sensibly when rendering latex.
    \- is a hyphenation, so it doesn't get displayed at all.

• Added a test for NULL when freeing subj->last_delim.

• Cleaned up setting of lower bounds for openers.
  We now use a much smaller array.

• Fix #178, quadratic parsing bug. Add pathological test.

• Slight improvement of clarity of logic in emph matching.

• Fix "multiple of 3" determination in emph/strong parsing.
  We need to store the length of the original delimiter run,
  instead of using the length of the remaining delimiters
  after some have been subtracted. Test case:
  a***b* c*. Thanks to Raph Levin for reporting.

• Correctly initialize chunk in S_process_line (Nick Wellnhofer, #170).
  The alloc member wasn't initialized. This also allows to add an
  assertion in chunk_rtrim which doesn't work for alloced chunks.

• Added 'make newbench'.

• scanners.c generated with re2c 0.16 (68K smaller!).

• scanners.re - fixed warnings; use * for fallback.

• Fixed some warnings in scanners.re.

• Update CaseFolding to latest (Kevin Wojniak, #168).

• Allow balanced nested parens in link destinations (Yuki Izumi, #166)

• Allocate enough bytes for backticks array.

• Inlines: Ensure that the delimiter stack is freed in subject.

• Fixed pathological cases with backtick code spans:

  • Removed recursion in scan_to_closing_backticks

  • Added an array of pointers to potential backtick closers
    to subject

  • This array is used to avoid traversing the subject again
    when we've already seen all the potential backtick closers.

  • Added a max bound of 1000 for backtick code span delimiters.

  • This helps with pathological cases like:

      x
      x `
      x ``
      x ```
      x ````
      ...
    

  • Added pathological test case.

  Thanks to Martin Mitáš for identifying the problem and for
  discussion of solutions.

• Remove redundant cmake_minimum_required (#163, @kainjow).

• Make shared and static libraries optional (Azamat H. Hackimov).
  Now you can enable/disable compilation and installation targets for
  shared and static libraries via -DCMARK_SHARED=ON/OFF and
  -DCMARK_STATIC=ON/OFF.

• Added support for built-in ${LIB_SUFFIX} feature (Azamat H.
  Hackimov). Replaced ${LIB_INSTALL_DIR} option with built-in
  ${LIB_SUFFIX} for installing for 32/64-bit systems. Normally,
  CMake will set ${LIB_SUFFIX} automatically for required enviroment.
  If you have any issues with it, you can override this option with
  -DLIB_SUFFIX=64 or -DLIB_SUFFIX="" during configuration.

• Add Makefile target and harness to fuzz with libFuzzer (Phil Turnbull).
  This can be run locally with make libFuzzer but the harness will be
  integrated into oss-fuzz for large-scale fuzzing.

• Advertise --validate-utf8 in usage information
  (Nguyễn Thái Ngọc Duy).

• Makefile: use warnings with re2c.

• README: Add link to Python wrapper, prettify languages list
  (Pavlo Kapyshin).

• README: Add link to cmark-scala (Tim Nieradzik, #196)

• Set policy for CMP0063 to avoid a warning (#162).
  Put set_policy under cmake version test.
  Otherwise we get errors in older versions of cmake.
• Use VERSION_GREATER to clean up cmake version test.
• Improve afl target. Use afl-clang by default. Set default for path.

• Update spec to 0.27.
• Fix warnings building with MSVC on Windows (#165, Hugh Bellamy).
• Fix CMAKE_C_VISIBILITY_PRESET for cmake versions greater than 1.8
  (e.g. 3.6.2) (#162, Hugh Bellamy). This lets us build swift-cmark
  on Windows, using clang-cl.
• Fix for non-matching entities (#161, Yuki Izumi).
• Modified print_delimiters (commented out) so it compiles again.
• make format: don't change order of includes.
• Changed logic for null/eol checks (#160).
  • only check once for "not at end of line"
  • check for null before we check for newline characters (the
    previous patch would fail for NULL + CR)
• Fix by not advancing past both \0 and \n (Yuki Izumi).
• Add test for NUL-LF sequence (Yuki Izumi).
• Fix memory leak in list parsing (Yuki Izumi).
• Use cmark_mem to free where used to alloc (Yuki Izumi).
• Allow a shortcut link before a ( (jgm/CommonMark#427).
• Allow tabs after setext header line (jgm/commonmark.js#109).
• Don't let URI schemes start with spaces.
• Fixed h2..h6 HTML blocks (jgm/CommonMark#430). Added regression test.
• Autolink scheme can contain digits (Gábor Csárdi).
• Fix nullary function declarations in cmark.h (Nick Wellnhofer).
  Fixes strict prototypes warnings.
• COPYING: Update file name and remove duplicate section and
  (Peter Eisentraut).
• Fix typo (Pavlo Kapyshin).

• Removed unnecessary typedef that caused build failure on
  some platforms.
• Use $(MAKE) in Makefile instead of hardcoded make (#146,
  Tobias Kortkamp).

• Implement spec changes for list items:
  • Empty list items cannot interrupt paragraphs.
  • Ordered lists cannot interrupt paragraphs unless
    they start with 1.
  • Removed "two blank lines break out of a list" feature.
• Fix sourcepos for blockquotes (#142).
• Fix sourcepos for atx headers (#141).
• Fix ATX headers and thematic breaks to allow tabs as well as spaces.
• Fix chunk_set_cstr with suffix of current string (#139,
  Nick Wellnhofer). It's possible that cmark_chunk_set_cstr is called
  with a substring (suffix) of the current string. Delay freeing of the
  chunk content to handle this case correctly.
• Export targets on installation (Jonathan Müller).
  This allows using them in other cmake projects.
• Fix cmake warning about CMP0048 (Jonathan Müller).
• commonmark renderer: Ensure we don't have a blank line
  before a code block when it's the first thing in a list
  item.
• Change parsing of strong/emph in response to spec changes.
  process_emphasis now gets better results in corner cases.
  The change is this: when considering matches between an interior
  delimiter run (one that can open and can close) and another delimiter
  run, we require that the sum of the lengths of the two delimiter
  runs mod 3 is not 0.
• Ported Robin Stocker's changes to link parsing in jgm/commonmark#101.
  This uses a separate stack for brackets, instead of putting them on the
  delimiter stack. This avoids the need for looking through the delimiter
  stack for the next bracket.
• cmark_reference_lookup: Return NULL if reference is null string.
• Fix character type detection in commonmark.c (Nick Wellnhofer).
  Fixes test failures on Windows and undefined behavior.
  • Implement cmark_isalpha.
  • Check for ASCII character before implicit cast to char.
  • Use internal ctype functions in commonmark.c.
• Better documentation of memory-freeing responsibilities.
  in cmark.h and its man page (#124).
• Use library functions to insert nodes in emphasis/link processing.
  Previously we did this manually, which introduces many
  places where errors can creep in.
• Correctly handle list marker followed only by spaces.
  Previously when a list marker was followed only by spaces,
  cmark expected the following content to be indented by
  the same number of spaces. But in this case we should
  treat the line just like a blank line and set list padding
  accordingly.
• Fixed a number of issues relating to line wrapping.
  • Extend CMARK_OPT_NOBREAKS to all renderers and add --nobreaks.
  • Do not autowrap, regardless of width parameter, if
    CMARK_OPT_NOBREAKS is set.
  • Fixed CMARK_OPT_HARDBREAKS for LaTeX and man renderers.
  • Ensure that no auto-wrapping occurs if
    CMARK_OPT_NOBREAKS is enabled, or if output is CommonMark and
    CMARK_OPT_HARDBREAKS is enabled.
• Set stdin to binary mode on Windows (Nick Wellnhofer, #113).
  This fixes EOLs when reading from stdin.
• Add library option to render softbreaks as spaces (Pavlo
  Kapyshin). Note that the NOBREAKS option is HTML-only
• renderer: no_linebreaks instead of no_wrap.
  We generally want this option to prohibit any breaking
  in things like headers (not just wraps, but softbreaks).
• Coerce realurllen to int. This is an alternate solution for pull
  request #132, which introduced a new warning on the comparison
  (Benedict Cohen).
• Remove unused variable link_text (Mathiew Duponchelle).
• Improved safety checks in buffer (Vicent Marti).
• Add new interface allowing specification of custom memory allocator
  for nodes (Vicent Marti). Added cmark_node_new_with_mem,
  cmark_parser_new_with_mem, cmark_mem to API.
• Reduce storage size for nodes by using bit flags instead of
  separate booleans (Vicent Marti).
• config: Add SSIZE_T compat for Win32 (Vicent Marti).
• cmake: Global handler for OOM situations (Vicent Marti).
• Add tests for memory exhaustion (Vicent Marti).
• Document in man page and public header that one should use the same
  memory allocator for every node in a tree.
• Fix ctypes in Python FFI calls (Nick Wellnhofer). This didn't cause
  problems so far because all types are 32-bit on 32-bit systems and
  arguments are passed in registers on x86-64. The wrong types could cause
  crashes on other platforms, though.
• Remove spurious failures in roundtrip tests. In the commonmark writer we
  separate lists, and lists and indented code, using a dummy HTML comment.
  So in evaluating the round-trip tests, we now strip out
  these comments. We also normalize HTML to avoid issues
  having to do with line breaks.
• Add 2016 to copyright (Kevin Burke).
• Added to_commonmark in test/cmark.py (for round-trip tests).
• spec_test.py - parameterize do_test with converter.
• spec_tests.py: exit code is now sum of failures and errors.
  This ensures that a failing exit code will be given when
  there are errors, not just with failures.
• Fixed round trip tests. Previously they actually ran
  cmark instead of the round-trip version, since there was a bug in
  setting the ROUNDTRIP variable (#131).
• Added new roundtrip_tests.py. This replaces the old use of simple shell
  scripts. It is much faster, and more flexible. (We will be able
  to do custom normalization and skip certain tests.)
• Fix tests under MinGW (Nick Wellnhofer).
• Fix leak in api_test (Mathieu Duponchelle).
• Makefile: have leakcheck stop on first error instead of going through
  all the formats and options and probably getting the same output.
• Add regression tests (Nick Wellnhofer).

• Open files in binary mode (#113, Nick Wellnhofer). Now that cmark
  supports different line endings, files must be openend in binary mode
  on Windows.
• Reset partially_consumed_tab on every new line (#114, Nick Wellnhofer).
• Handle buffer split across a CRLF line ending (#117). Adds an internal
  field to the parser struct to keep track of last_buffer_ended_with_cr.
  Added test.

• Release with no code changes. cmark version was mistakenly set to
  0.25.1 in the 0.25.0 release (#112), so this release just
  ensures that this will cause no confusion later.

• Fixed tabs in indentation (#101). This patch fixes S_advance_offset
  so that it doesn't gobble a tab character when advancing less than the
  width of a tab.

• Added partially_consumed_tab to parser. This keeps track of when we
  have gotten partway through a tab when consuming initial indentation.

• Simplified add_line (only need parser parameter).

• Properly handle partially consumed tab. E.g. in

  - foo
  
   <TAB><TAB>bar
  

  we should consume two spaces from the second tab, including two spaces
  in the code block.

• Properly handle tabs with blockquotes and fenced blocks.

• Fixed handling of tabs in lists.

• Clarified logic in S_advance_offset.

• Use an assertion to check for in-range html_block_type.
  It's a programming error if the type is out of range.

• Refactored S_processLines to make the logic easier to
  understand, and added documentation (Mathieu Duponchelle).

• Removed unnecessary check for empty string_content.

• Factored out contains_inlines.

• Moved the cmake minimum version to top line of CMakeLists.txt
  (tinysun212).

• Fix ctype(3) usage on NetBSD (Kamil Rytarowski). We need to cast value
  passed to isspace(3) to unsigned char to explicitly prevent possibly
  undefined behavior.

• Compile in plain C mode with MSVC 12.0 or newer (Nick Wellnhofer).
  Under MSVC, we used to compile in C++ mode to get some C99 features
  like mixing declarations and code. With newer MSVC versions, it's
  possible to build in plain C mode.

• Switched from "inline" to "CMARK_INLINE" (Nick Wellnhofer).
  Newer MSVC versions support enough of C99 to be able to compile cmark
  in plain C mode. Only the "inline" keyword is still unsupported.
  We have to use "__inline" instead.

• Added include guards to config.h

• config.h.in - added compatibility snprintf, vsnprintf for MSVC.

• Replaced sprintf with snprintf (Marco Benelli).

• config.h: include stdio.h for _vscprintf etc.

• Include starg.h when needed in config.h.

• Removed an unnecessary C99-ism in buffer.c. This helps compiling on
  systems like luarocks that don't have all the cmake configuration
  goodness (thanks to carlmartus).

• Don't use variable length arrays (Nick Wellnhofer).
  They're not supported by MSVC.

• Test with multiple MSVC versions under Appveyor (Nick Wellnhofer).

• Fix installation dir of man-pages on NetBSD (Kamil Rytarowski).

• Fixed typo in cmark.h comments (Chris Eidhof).

• Clarify in man page that cmark_node_free frees a node's children too.

• Fixed documentation of --width in man page.

• Require re2c >= 1.14.2 (#102).

• Generated scanners.c with more recent re2c.

• Commonmark renderer:
  • Use HTML comment, not two blank lines, to separate a list
    item from a following code block or list. This makes the
    output more portable, since the "two blank lines" rule is
    unique to CommonMark. Also, it allows us to break out of
    a sublist without breaking out of all levels of nesting.
  • is_autolink - handle case where link has no children,
    which previously caused a segfault.
  • Use 4-space indent for bullet lists, for increased portability.
  • Use 2-space + newline for line break for increased portability (#90).
  • Improved punctuation escaping. Previously all ) and
    . characters after digits were escaped; now they are
    only escaped if they are genuinely in a position where
    they'd cause a list item. This is achieved by changes in
    render.c: (a) renderer->begin_content is only set to
    false after a string of digits at the beginning of the
    line, and (b) we never break a line before a digit.
    Also, begin_content is properly initialized to true.
• Handle NULL root in consolidate_text_nodes.

• [API change] Added cmark_node_replace(oldnode, newnode).
• Updated spec.txt to 0.24.
• Fixed edge case with escaped parens in link destination (#97).
  This was also checked against the #82 case with asan.
• Removed unnecessary check for fenced in cmark_render_html.
  It's sufficient to check that the info string is empty.
  Indeed, those who use the API may well create a code block
  with an info string without explicitly setting fenced.
• Updated format of test/smart_punct.txt.
• Updated test/spec.txt, test/smart_punct.txt, and
  spec_tests.py to new format.
• Fixed get_containing_block logic in src/commonmark.c.
  This did not allow for the possibility that a node might have no
  containing block, causing the commonmark renderer to segfault if
  passed an inline node with no block parent.
• Fixed string representations of CUSTOM_BLOCK,
  CUSTOM_INLINE. The old versions raw_inline and
  raw_block were being used, and this led to incorrect xml output.
• Use default opts in python sample wrapper.
• Allow multiline setext header content, as per spec.
• Don't allow spaces in link destinations, even with pointy brackets.
  Conforms to latest change in spec.
• Updated scheme scanner according to spec change. We no longer use
  a whitelist of valid schemes.
• Allow any kind of nodes as children of CUSTOM_BLOCK (#96).
• cmark.h: moved typedefs for iterator into iterator section.
  This just moves some code around so it makes more sense
  to read, and in the man page.
• Fixed make_man_page.py so it includes typedefs again.

• [API change] Added CUSTOM_BLOCK and CUSTOM_INLINE node types.
  They are never generated by the parser, and do not correspond
  to CommonMark elements. They are designed to be inserted by
  filters that postprocess the AST. For example, a filter might
  convert specially marked code blocks to svg diagrams in HTML
  and tikz diagrams in LaTeX, passing these through to the renderer
  as a CUSTOM_BLOCK. These nodes can have children, but they
  also have literal text to be printed by the renderer "on enter"
  and "on exit." Added cmark_node_get_on_enter,
  cmark_node_set_on_enter, cmark_node_get_on_exit,
  cmark_node_set_on_exit to API.
• [API change] Rename NODE_HTML -> NODE_HTML_BLOCK,
  NODE_INLINE_HTML -> NODE_HTML_INLINE. Define aliases
  so the old names still work, for backwards compatibility.
• [API change] Rename CMARK_NODE_HEADER -> CMARK_NODE_HEADING.
  Note that for backwards compatibility, we have defined aliases:
  CMARK_NODE_HEADER = CMARK_NODE_HEADING,
  cmark_node_get_header_level = cmark_node_get_heading_level, and
  cmark_node_set_header_level = cmark_node_set_heading_level.
• [API change] Rename CMARK_NODE_HRULE -> CMARK_NODE_THEMATIC_BREAK.
  Defined the former as the latter for backwards compatibility.
• Don't allow space between link text and link label in a reference link
  (spec change).
• Separate parsing and rendering opts in cmark.h (#88).
  This change also changes some of these constants' numerical values,
  but nothing should change in the API if you use the constants
  themselves. It should now be clear in the man page which
  options affect parsing and which affect rendering.
• xml renderer - Added xmlns attribute to document node (jgm/CommonMark#87).
• Commonmark renderer: ensure html blocks surrounded by blanks.
  Otherwise we get failures of roundtrip tests.
• Commonmark renderer: ensure that literal characters get escaped
  when they're at the beginning of a block, e.g. > \- foo.
• LaTeX renderer - better handling of internal links.
  Now we render [foo](#bar) as \protect\hyperlink{bar}{foo}.
• Check for NULL pointer in _scan_at (#81).
• Makefile.nmake: be more robust when cmake is missing. Previously,
  when cmake was missing, the build dir would be created anyway, and
  subsequent attempts (even with cmake) would fail, because cmake would
  not be run. Depending on build/CMakeFiles is more robust -- this won't
  be created unless cmake is run. Partially addresses #85.
• Fixed DOCTYPE in xml output.
• commonmark.c: fix size_t to int. This fixes an MSVC warning
  "conversion from 'size_t' to 'int', possible loss of data" (Kevin Wojniak).
• Correct string length in cmark_parse_document example (Lee Jeffery).
• Fix non-ASCII end-of-line character check (andyuhnak).
• Fix "declaration shadows a local variable" (Kevin Wojniak).
• Install static library (jgm/CommonMark#381).
• Fix warnings about dropping const qualifier (Kevin Wojniak).
• Use full (unabbreviated) versions of constants (CMARK_...).
• Removed outdated targets from Makefile.
• Removed need for sudo in make bench.
• Improved benchmark. Use longer test, since time has limited resolution.
• Removed bench.h and timing calls in main.c.
• Updated API docs; getters return empty strings if not set
  rather than NULL, as previously documented.
• Added api_tests for custom nodes.
• Made roundtrip test part of the test suite run by cmake.
• Regenerate scanners.c using re2c 0.15.3.
• Adjusted scanner for link url. This fixes a heap buffer overflow (#82).
• Added version number (1.0) to XML namespace. We don't guarantee
  stability in this until 1.0 is actually released, however.
• Removed obsolete TIMER macro.
• Make LIB_INSTALL_DIR configurable (Mathieu Bridon, #79).
• Removed out-of-date luajit wrapper.
• Use input, not parser->curline to determine last line length.
• Small optimizations in _scan_at.
• Replaced hard-coded 4 with TAB_STOP.
• Have make format reformat api tests as well.
• Added api tests for man, latex, commonmark, and xml renderers (#51).
• render.c: added begin_content field. This is like begin_line except
  that it doesn't trigger production of the prefix. So it can be set
  after an initial prefix (say >) is printed by the renderer, and
  consulted in determining whether to escape content that has a special
  meaning at the beginning of a line. Used in the commonmark renderer.
• Python 3.5 compatibility: don't require HTMLParseError (Zhiming Wang).
  HTMLParseError was removed in Python 3.5. Since it could never be thrown
  in Python 3.5+, we simply define a placeholder when HTMLParseError
  cannot be imported.
• Set convert_charrefs=False in normalize.py (#83). This defeats the
  new default as of python 3.5, and allows the script to work with python
  3.5.