This is release v1.9.0, "Schwibbogen". As usual, it contains numerous bug fixes, compatibility improvements, and new features.

This is expected to be the final release in the libgit2 v1.x lineage. libgit2 v2.0 is expected to be the next version, with support for SHA256 moving to "supported" status (out of "experimental" status). This means that v2.0 will have API and ABI changes to support SHA256, as well as otherbreaking changes.

Major changes

• Documentation improvements
  We've launched a new website for our API reference docs athttps://libgit2.org/docs/reference/main. To support this, we've updated the documentation to ensure that all APIs are well-documented, and added docurium-style specifiers to indicate more depth about the API surface.

  We now also publish a JSON blob with the API structure and the documentation that may be helpful for binding authors.

• TLS cipher updates
  libgit2 has updated our TLS cipher selection to match the "compatibility" cipher suite settings asdocumented by Mozilla.

• Blame improvements
  The blame API now contains committer information and commit summaries for blame hunks, and the ability to get information about the line of text that was modified. In addition, a CLI blame command has been added so that the blame functionality can be benchmarked by our benchmark suite.

• More CLI commands
  libgit2 has addedblame andinit commands, which have allowed forfurther benchmarking and several API improvements and git compatibility updates.

• Warning when configuring without SHA1DC
  Users are encouraged to use SHA1DC, which isgit's hash;users should not use SHA1 in the general case. Users will now be warned if they try to configure cmake with a SHA1 backend (-DUSE_SHA1=...).

Breaking changes

There are several ABI-breaking changes that integrators, particularly maintainers of bindings or FFI users, may want to be aware of.

• Blame hunk structure updates (ABI breaking change)
  There are numerous additions to thegit_blame_hunk structure to accommodate more information about the blame process.

• Checkout strategy updates (ABI breaking change)
  The values forGIT_CHECKOUT_SAFE andGIT_CHECKOUT_NONE have been updated.GIT_CHECKOUT_SAFE is now0; this was implicitly the default value (with the options constructors setting that as the checkout strategy). It is now the default if the checkout strategy is set to0. This allows for an overall code simplification in the library.

• Configuration entry member removal (ABI breaking change)
  Thegit_config_entry structure no longer contains afree member; this was an oversight as end-users should not try to free that structure.

• Configuration backend function changes (ABI breaking change)
  git_config_backends should now returngit_config_backend_entry objects instead ofgit_config_entry objects. This allows backends to provide a mechanism to nicely free the configuration entries that they provide.

• update_refs callback for remotes (ABI breaking change)
  Theupdate_refs callback was added to thegit_remote_callbacks structure to provide additional information about updated refs; in particular, thegit_refspec is included for more information about the remote ref. Theupdate_refs callback will be preferred over the now deprecatedupdate_tips callback.

What's Changed

New features

• Thegit_signature_default_from_env API will now produce a pair ofgit_signatures representing the author, and the committer, taking theGIT_AUTHOR_NAME andGIT_COMMITTER_NAME environment variables into account. Added by@u-quark inUse environment variables when creating signatures #6706

• packbuilder can now be interrupted from a callback. Added@roberth inMake packbuilder interruptible using progress callback #6874

• libgit2 now claims to honor thepreciousObject repository extension. This extension indicates that the client will never delete objects (in other words, will not garbage collect). libgit2 has no functionality to remove objects, so it implicitly obeys this in all cases. Added by@ethomson inrepo: support the preciousObjects extension #6886

• Push status will be reported even when a push fails. This is useful to give information from the server about possible updates, even when the overall status failed. Added by@yerseg inpush: report a push status even the push has failed #6876

• You can now generate a thin pack from a mempack instance usinggit_mempack_write_thin_pack. Added by@roberth inAddgit_mempack_write_thin_pack #6875

• The newLIBGIT2_VERSION_CHECK macro will indicate whether the version of libgit2 being compiled against is at least the version specified. For example:#if LIBGIT2_VERSION_CHECK(1, 6, 3) is true for libgit2 version 1.6.3 or newer. In addition, the newLIBGIT2_VERSION_NUMBER macro will return an integer version representing the libgit2 version number. For example, for version 1.6.3,LIBGIT2_VERSION_NUMBER will evaluate to010603. Added by@HamedMasafi inAdd LIBGIT2_VER_CHECK Macro for Version Comparison #6882

• Custom X509 certificates can be added to OpenSSL's certificate store using theGIT_OPT_ADD_SSL_X509_CERT option. Added by@yerseg inssl: ability to add raw X509 certs to the cert store #6877

• The libgit2 compatibility CLI now has agit blame command. Added by@ethomson inIntroduce a blame command #6907

• Remote callbacks now provide anupdate_refs callback so that users can now get therefspec of the updated reference during push. This gives more complete information about the remote reference that was updated. Added by@ethomson inremote: add update_refs with git_refspec #6559

• An optional FIPS-compliant mode for hashing is now available; you can set-DUSE_SHA256=OpenSSL-FIPS to enable it. Added by @marcind-dot inAdd OpenSSL-FIPS option to USE_SHA256 CMake flag #6906

• The git-compatible CLI now supports thegit init command, which has been useful in identifying API improvements and incompatibilities with git. Added by@ethomson inCLI: introduceinit command #6984

• Consumers can now query more information about how libgit2 was compiled, and query the "backends" that libgit2 uses. Added by@ethomson inAllow consumers to query the "backends" that libgit2 was built with #6971

Bug fixes

• Fix constness issue introduced incommit: introduce git_commit_create_from_stage #6716 by@ethomson in Fix constness issue introduced in #6716 #6829
• odb: conditionalgit_hash_ctx_cleanup ingit_odb_stream by@gensmusic inodb: conditional git_hash_ctx_cleanup in git_odb_stream #6836
• Fix shallow root maintenance during fetch by@kcsaul inFix shallow root maintenance during fetch #6846
• Headers cleanup by@anatol inHeaders cleanup #6842
• http: Initializeon_status when using the http-parser backend by@civodul inhttp: Initialize ‘on_status’ when using the http-parser backend. #6870
• Leak intruncate_racily_clean in index.c by@lstoppa inLeak in truncate_racily_clean in index.c #6884
• ssh: Omit port option from ssh command unless specified in remote url by@jayong93 inssh: Omit port option from ssh command unless specified in remote url #6845
• diff: print the file header onGIT_DIFF_FORMAT_PATCH_HEADER by@carlosmn indiff: print the file header on GIT_DIFF_FORMAT_PATCH_HEADER #6888
• Add more robust reporting to SecureTransport errors on macos by@vcfxb inAdd more robust reporting to SecureTransport errors on macos #6848
• transport: do not filter tags based on ref dir in local by@rindeal intransport: do not filter tags based on ref dir in local #6881
• push: handle tags to blobs by@ethomson inpush: handle tags to blobs #6898
• Fixes for OpenSSL dynamic by@ethomson inFixes for OpenSSL dynamic #6901
• realpath: unbreak build on OpenBSD by@ajacoutot inrealpath: unbreak build on OpenBSD #6932
• util/win32: Continue if access is denied when deleting a folder by@lrm29 inutil/win32: Continue if access is denied when deleting a folder. #6929
• object:git_object_short_id fails with core.abbrev string values by@lrm29 in object: git_object_short_id fails with core.abbrev string values #6944
• Clear data after negotiation by@lrm29 inClear data after negotiation #6947
• smart: ignore shallow/unshallow packets during ACK processing by@kempniu insmart: ignore shallow/unshallow packets during ACK processing #6973

Security fixes

• ssh: Include rsa-sha2-256 and rsa-sha2-512 in the list of hostkey types by@lrm29 inssh: Include rsa-sha2-256 and rsa-sha2-512 in the list of hostkey types #6938
• TLS: v1.2 and updated cipher list by@ethomson inTLS: v1.2 and updated cipher list #6960

Code cleanups

• checkout: make safe checkout the default by@ethomson incheckout: make safe checkout the default #6037
• url: track whether url explicitly specified a port by@ethomson inurl: track whether url explicitly specified a port #6851
• config: removefree ptr fromgit_config_entry by@ethomson inconfig: removefree ptr fromgit_config_entry #6804
• Add SecCopyErrorMessageString for iOS and update README for iOS by@Kyle-Ye inAdd SecCopyErrorMessageString for iOS and update README for iOS #6862
• vector: free is now dispose by@ethomson invector: free is now dispose #6896
• hashmap: a libgit2-idiomatic khash by@ethomson inhashmap: a libgit2-idiomatic khash #6897
• hashmap: asserts by@ethomson inhashmap: asserts #6902
• hashmap: further asserts by@ethomson inhashmap: further asserts #6904
• MakeGIT_WIN32 an internal declaration by@ethomson inMakeGIT_WIN32 an internal declaration #6940
• pathspec: additional pathspec wildcard tests by@ethomson inpathspec: additional pathspec wildcard tests #6959
• repo: don't require option whentemplate_path is specified by@ethomson inrepo: don't require option whentemplate_path is specified #6983
• options: update X509 cert constant by@ethomson inoptions: update X509 cert constant #6974
• remote: Handle fetching negative refspecs by@ryan-ph inremote: Handle fetching negative refspecs #6962
• Restore tls v1.0 support temporarily by@ethomson inRestore tls v1.0 support temporarily #6964
• SHA256 improvements by@ethomson inSHA256 improvements #6965

Benchmarks

• Add benchmarks for blame by@ethomson inAdd benchmarks for blame #6920

Build and CI improvements

• README: add experimental builds to ci table by@ethomson inREADME: add experimental builds to ci table #6816
• Update stransport.c by@ethomson inUpdate stransport.c #6891
• stransport: initialize for iOS by@ethomson instransport: initialize for iOS #6893
• CI updates by@ethomson inCI updates #6895
• Configurable C standard by@ethomson inConfigurable C standard #6911
• cmake: update python locator by@ethomson incmake: update python locator #6915
• ci: don't run Windows SHA256 gitdaemon tests by@ethomson inci: don't run Windows SHA256 gitdaemon tests #6916
• cmake-standard c standards by@ethomson incmake-standard c standards #6914
• ci: don't run Windows SHA256 gitdaemon tests by@ethomson inci: don't run Windows SHA256 gitdaemon tests #6919
• Improve dependency selection in CMake by@ethomson inImprove dependency selection in CMake #6924
• ci: port latest fixes to nightlies by@ethomson inci: port latest fixes to nightlies #6926
• cmake: warn for not using sha1dc by@ethomson incmake: warn for not using sha1dc #6986

Documentation improvements

• Fix docs forgit_odb_stream_read return value. by@ehuss inFix docs for git_odb_stream_read return value. #6837
• docs: Add instructions to build examples by@thymusvulgaris indocs: Add instructions to build examples #6839
• Fix contradictory phrase in SECURITY.md by@Kyle-Ye inFix contradictory phrase in SECURITY.md #6859
• Update README.md by@Kyle-Ye inUpdate README.md #6860
• README updates by@ethomson inREADME updates #6908
• typo: s/size on bytes/size in bytes/ by@John-Colvin intypo: s/size on bytes/size in bytes/ #6909
• readme: add OpenSSF best practices badge by@ethomson inreadme: add OpenSSF best practices badge #6925
• Update documentation ofmerge_base_many by@Caleb-T-Owens inUpdate documentation ofmerge_base_many #6927
• Include documentation generator by@ethomson inInclude documentation generator #6945
• Update documentation generation workflow by@ethomson inUpdate documentation generation workflow #6948
• Improve documentation and validate during CI by@ethomson inImprove documentation and validate during CI #6949
• Add search functionality to our docs generator by@ethomson inAdd search functionality to our docs generator #6953
• Documentation: don't resort versions by@ethomson inDocumentation: don't resort versions #6954
• Documentation: updaterefdb_backend docs by@ethomson inDocumentation: update refdb_backend docs #6955
• Documentation: clean up old documentation by@ethomson inDocumentation: clean up old documentation #6957
• docs: remind people aboutgit_libgit2_init by@ethomson indocs: remind people aboutgit_libgit2_init #6958
• Update changelog with v1.8.4 content by@ethomson inUpdate changelog with v1.8.4 content #6961

Git compatibility fixes

• Limit.gitattributes and.gitignore files to 100 MiB by@csware inLimit .gitattributes and .gitignore files to 100 MiB #6834
• refs: Handle normalizing negative refspecs by@ryan-ph inrefs: Handle normalizing negative refspecs #6951
• repo: put a newline on the .git link file by@ethomson inrepo: put a newline on the .git link file #6981

Dependency updates

• zlib: update bundled zlib to v1.3.1 by@ethomson inzlib: update bundled zlib to v1.3.1 #6905
• Update ntlmclient dependency by@ethomson inUpdate ntlmclient dependency #6912

Other changes

• Create FUNDING.json by@BenJam inCreate FUNDING.json #6853

New Contributors

• @gensmusic made their first contribution inodb: conditional git_hash_ctx_cleanup in git_odb_stream #6836
• @u-quark made their first contribution inUse environment variables when creating signatures #6706
• @thymusvulgaris made their first contribution indocs: Add instructions to build examples #6839
• @anatol made their first contribution inHeaders cleanup #6842
• @BenJam made their first contribution inCreate FUNDING.json #6853
• @Kyle-Ye made their first contribution inFix contradictory phrase in SECURITY.md #6859
• @civodul made their first contribution inhttp: Initialize ‘on_status’ when using the http-parser backend. #6870
• @lstoppa made their first contribution inLeak in truncate_racily_clean in index.c #6884
• @jayong93 made their first contribution inssh: Omit port option from ssh command unless specified in remote url #6845
• @roberth made their first contribution inMake packbuilder interruptible using progress callback #6874
• @vcfxb made their first contribution inAdd more robust reporting to SecureTransport errors on macos #6848
• @yerseg made their first contribution inpush: report a push status even the push has failed #6876
• @rindeal made their first contribution intransport: do not filter tags based on ref dir in local #6881
• @HamedMasafi made their first contribution inAdd LIBGIT2_VER_CHECK Macro for Version Comparison #6882
• @John-Colvin made their first contribution intypo: s/size on bytes/size in bytes/ #6909
• @marcind-dot made their first contribution inAdd OpenSSL-FIPS option to USE_SHA256 CMake flag #6906
• @ajacoutot made their first contribution inrealpath: unbreak build on OpenBSD #6932
• @Caleb-T-Owens made their first contribution inUpdate documentation ofmerge_base_many #6927
• @ryan-ph made their first contribution inrefs: Handle normalizing negative refspecs #6951
• @bmarques1995 made their first contribution inAdd cmake package targets #6840

Full Changelog:v1.8.4...v1.9.0