libgit2 v0.22.0 RC1 发布，此版本主要是 bug 修复，修改了一些 API，更新内容如下：
File unlocks are atomic again via rename. Read-only files on Windows are
made read-write if necessary.
Share open packfiles across repositories to share descriptors and mmaps.
Use a map for the treebuilder, making insertion O(1)
Introduce reference transactions, which allow multiple references to
be locked at the same time and updates be queued. This also allows
us to safely update a reflog with arbitrary contents, as we need to
do for stash.
The index' tree cache is now filled upon read-tree and write-tree
and the cache is written to disk.
LF -> CRLF filter refuses to handle mixed-EOL files
LF -> CRLF filter now runs when * text = auto (with Git for Windows 1.9.4)
The git_transport structure definition has moved into the sys/transport.h
The ssh transport supports asking the remote host for accepted
credential types as well as multiple challeges using a single
connection. This requires to know which username you want to connect
as, so this introduces the USERNAME credential type which the ssh
transport will use to ask for the username.
The build system now accepts an option EMBED_SSH_PATH which when set
tells it to include a copy of libssh2 at the given location. This is
enabled for MSVC.
libgit2 no longer automatically sets the OpenSSL locking
functions. This is not something which we can know to do. A
last-resort convenience function is provided in sys/openssl.h,
git_openssl_set_locking() which can be used to set the locking.
The git_transport_register function no longer takes a priority and takes
a URL scheme name (eg "http") instead of a prefix like "http://"
The git_remote_set_transport function now sets a transport factory function,
rather than a pre-existing transport instance.
A factory function for ssh has been added which allows to change the
path of the programs to execute for receive-pack and upload-pack on
the server, git_transport_ssh_with_paths.
git_remote_rename() now takes the repository and the remote's
current name. Accepting a remote indicates we want to change it,
which we only did partially. It is much clearer if we accept a name
and no loaded objects are changed.
git_remote_delete() now accepts the repository and the remote's name
instead of a loaded remote.
git_remote_supported_url() has been removed as it has become
essentially useless with rsync-style ssh paths.
The git_clone_options struct no longer provides the ignore_cert_errors or
remote_name members for remote customization.
Instead, the git_clone_options struct has two new members, remote_cb and
remote_cb_payload, which allow the caller to completely override the remote
creation process. If needed, the caller can use this callback to give their
remote a name other than the default (origin) or disable cert checking.
The remote_callbacks member has been preserved for convenience, although it
is not used when a remote creation callback is supplied.
The git_clone_options struct now provides repository_cb and
repository_cb_payload to allow the user to create a repository with
The option to ignore certificate errors via git_remote_cert_check()
is no longer present. Instead, git_remote_callbacks has gained a new
entry which lets the user perform their own certificate checks.
git_clone_into and git_clone_local_into have been removed from the
public API in favour of git_clone callbacks
Add support for refspecs with the asterisk in the middle of a
Fetching now performs opportunistic updates. To achieve this, we
introduce a difference between active and passive refspecs, which
make git_remote_download and git_remote_fetch to take a list of
resfpecs to be the active list, similarly to how git fetch accepts a
list on the command-line.
Rename git_remote_load() to git_remote_lookup() to bring it in line
with the rest of the lookup functions.
The git_push struct to perform a push has been replaced with
git_remote_upload(). The refspecs and options are passed as a
function argument. git_push_update_tips() is now also
git_remote_update_tips() and the callbacks are in the same struct as
Introduce git_merge_bases() and the git_oidarray type to expose all
merge bases between two commits.
Introduce git_merge_bases_many() to expose all merge bases between
git_merge_head is now git_annotated_commit, to better reflect its usage
for multiple functions (including rebase)
Introduce rebase functionality (using the merge algorithm only).
Introduce git_rebase_init() to begin a new rebase session,
git_rebase_open() to open an in-progress rebase session,
git_rebase_commit() to commit the current rebase operation,
git_rebase_next() to apply the next rebase operation,
git_rebase_abort() to abort an in-progress rebase and git_rebase_finish()
to complete a rebase operation.
Introduce git_note_author() and git_note_committer() to get the author
and committer information on a git_note, respectively.
git_note_create() has changed the position of the notes reference
name to match git_note_remove().
The THREADSAFE option to build libgit2 with threading support has
been flipped to be on by default.
The context_lines and interhunk_lines fields in git_diff_options are
now uint32_t instead of uint16_t. This allows to set them to UINT_MAX,
in effect asking for "infinite" context e.g. to iterate over all the
unmodified lines of a diff.
git_status_file now takes an exact path. Use git_status_list_new if
pathspec searching is needed.
The fetch behavior of remotes with autotag set to GIT_REMOTE_DOWNLOAD_TAGS_ALL
has been changed to match git 1.9.0 and later. In this mode, libgit2 now
fetches all tags in addition to whatever else needs to be fetched.
The remote object has learnt to prune remote-tracking branches. If
the remote is configured to do so, this will happen via
git_remote_fetch(). You can also call git_remote_prune() after
connecting or fetching to perform the prune.
git_threads_init() and git_threads_shutdown() have been renamed to
git_libgit2_init() and git_libgit2_shutdown() to better explain what
their purpose is, as it's grown to be more than just about threads.
git_libgit2_init() and git_libgit2_shutdown() now return the number of
initializations of the library, so consumers may schedule work on the
git_treebuilder_new (was git_treebuilder_create) now takes a
repository so that it can query repository configuration.
Subsequently, git_treebuilder_write no longer takes a repository.
git_treebuilder_create was renamed to git_treebuilder_new to better
reflect it being a constructor rather than something which writes to
git_checkout now handles case-changing renames correctly on
case-insensitive filesystems; for example renaming "readme" to "README".
git_index_name_entrycount() and git_index_reuc_entrycount() now
return size_t instead of unsigned int.
The search for libssh2 is now done via pkg-config instead of a
custom search of a few directories.
Add support for core.protectHFS and core.protectNTFS. Add more
validation for filenames which we write such as references.
The local transport now generates textual progress output like
git-upload-pack does ("counting objects").
The git_submodule_update function was renamed to
git_submodule_update_strategy. git_submodule_update is now used to
provide functionalty similar to "git submodule update".
libgit2 是一个可移植、纯C语言实现的 Git 核心开发包，你可以使用它来编写自定义的 Git 应用。
libgit2已被广泛应用在许多应用程序上，包括GitHub网站，还被应用在Plastic SCM和强大的微软Visual Studio工具箱。
Parrot Virtual Machine：https://github.com/letolabs/parrot-libgit2