Git 2.22 Release Notes
======================

Updates since v2.21
-------------------

UI, Workflows & Features

 * "git checkout --no-overlay" can be used to trigger a new mode of
   checking out paths out of the tree-ish, that allows paths that
   match the pathspec that are in the current index and working tree
   and are not in the tree-ish.

 * The %(trailers) formatter in "git log --format=..."  now allows to
   optionally pick trailers selectively by keyword, show only values,
   etc.

 * Four new configuration variables {author,committer}.{name,email}
   have been introduced to override user.{name,email} in more specific
   cases.

 * Command-line completion (in contrib/) learned to tab-complete the
   "git submodule absorbgitdirs" subcommand.

 * "git branch" learned a new subcommand "--show-current".

 * Output from "diff --cc" did not show the original paths when the
   merge involved renames.  A new option adds the paths in the
   original trees to the output.

 * The command line completion (in contrib/) has been taught to
   complete more subcommand parameters.

 * The final report from "git bisect" used to show the suspected
   culprit using a raw "diff-tree", with which there is no output for
   a merge commit.  This has been updated to use a more modern and
   human readable output that still is concise enough.

 * "git rebase --rebase-merges" replaces its old "--preserve-merges"
   option; the latter is now marked as deprecated.

 * Error message given while cloning with --recurse-submodules has
   been updated.


Performance, Internal Implementation, Development Support etc.

 * The diff machinery, one of the oldest parts of the system, which
   long predates the parse-options API, uses fairly long and complex
   handcrafted option parser.  This is being rewritten to use the
   parse-options API.

 * The implementation of pack-redundant has been updated for
   performance in a repository with many packfiles.

 * A more structured way to obtain execution trace has been added.

 * "git prune" has been taught to take advantage of reachability
   bitmap when able.

 * The command line parser of "git commit-tree" has been rewritten to
   use the parse-options API.

 * Suggest GitGitGadget instead of submitGit as a way to submit
   patches based on GitHub PR to us.


Fixes since v2.21
-----------------

 * "git prune-packed" did not notice and complain against excess
   arguments given from the command line, which now it does.
   (merge 9b0bd87ed2 rj/prune-packed-excess-args later to maint).

 * Split-index fix.
   (merge 6e37c8ed3c nd/split-index-null-base-fix later to maint).

 * "git diff --no-index" may still want to access Git goodies like
   --ext-diff and --textconv, but so far these have been ignored,
   which has been corrected.
   (merge 287ab28bfa jk/diff-no-index-initialize later to maint).

 * Unify RPC code for smart http in protocol v0/v1 and v2, which fixes
   a bug in the latter (lack of authentication retry) and generally
   improves the code base.
   (merge a97d00799a jt/http-auth-proto-v2-fix later to maint).

 * The include file compat/bswap.h has been updated so that it is safe
   to (accidentally) include it more than once.
   (merge 33aa579a55 jk/guard-bswap-header later to maint).

 * The set of header files used by "make hdr-check" unconditionally
   included sha256/gcrypt.h, even when it is not used, causing the
   make target to fail.  We now skip it when GCRYPT_SHA256 is not in
   use.
   (merge f23aa18e7f rj/hdr-check-gcrypt-fix later to maint).

 * The Makefile uses 'find' utility to enumerate all the *.h header
   files, which is expensive on platforms with slow filesystems; it
   now optionally uses "ls-files" if working within a repository,
   which is a trick similar to how all sources are enumerated to run
   ETAGS on.
   (merge 92b88eba9f js/find-lib-h-with-ls-files-when-possible later to maint).

 * "git rebase" that was reimplemented in C did not set ORIG_HEAD
   correctly, which has been corrected.
   (merge cbd29ead92 js/rebase-orig-head-fix later to maint).

 * Dev support.
   (merge f545737144 js/stress-test-ui-tweak later to maint).

 * CFLAGS now can be tweaked when invoking Make while using
   DEVELOPER=YesPlease; this did not work well before.
   (merge 6d5d4b4e93 ab/makefile-help-devs-more later to maint).

 * "git fsck --connectivity-only" omits computation necessary to sift
   the objects that are not reachable from any of the refs into
   unreachable and dangling.  This is now enabled when dangling
   objects are requested (which is done by default, but can be
   overridden with the "--no-dangling" option).
   (merge 8d8c2a5aef jk/fsck-doc later to maint).

 * On platforms where "git fetch" is killed with SIGPIPE (e.g. OSX),
   the upload-pack that runs on the other end that hangs up after
   detecting an error could cause "git fetch" to die with a signal,
   which led to a flakey test.  "git fetch" now ignores SIGPIPE during
   the network portion of its operation (this is not a problem as we
   check the return status from our write(2)s).
   (merge 143588949c jk/no-sigpipe-during-network-transport later to maint).

 * A recent update broke "is this object available to us?" check for
   well-known objects like an empty tree (which should yield "yes",
   even when there is no on-disk object for an empty tree), which has
   been corrected.
   (merge f06ab027ef jk/virtual-objects-do-exist later to maint).

 * The setup code has been cleaned up to avoid leaks around the
   repository_format structure.
   (merge e8805af1c3 ma/clear-repository-format later to maint).

 * "git config --type=color ..." is meant to replace "git config --get-color"
   but there is a slight difference that wasn't documented, which is
   now fixed.
   (merge cd8e7593b9 jk/config-type-color-ends-with-lf later to maint).

 * When the "clean" filter can reduce the size of a huge file in the
   working tree down to a small "token" (a la Git LFS), there is no
   point in allocating a huge scratch area upfront, but the buffer is
   sized based on the original file size.  The convert mechanism now
   allocates very minimum and reallocates as it receives the output
   from the clean filter process.
   (merge 02156ab031 jh/resize-convert-scratch-buffer later to maint).

 * "git rebase" uses the refs/rewritten/ hierarchy to store its
   intermediate states, which inherently makes the hierarchy per
   worktree, but it didn't quite work well.
   (merge b9317d55a3 nd/rewritten-ref-is-per-worktree later to maint).

 * "git log -L<from>,<to>:<path>" with "-s" did not suppress the patch
   output as it should.  This has been corrected.
   (merge 05314efaea jk/line-log-with-patch later to maint).

 * "git worktree add" used to do a "find an available name with stat
   and then mkdir", which is race-prone.  This has been fixed by using
   mkdir and reacting to EEXIST in a loop.
   (merge 7af01f2367 ms/worktree-add-atomic-mkdir later to maint).

 * Build update for SHA-1 with collision detection.
   (merge 07a20f569b jk/sha1dc later to maint).

 * Code cleanup, docfix, build fix, etc.
   (merge 11f470aee7 jc/test-yes-doc later to maint).
   (merge 90503a240b js/doc-symref-in-proto-v1 later to maint).
   (merge 5c326d1252 jk/unused-params later to maint).
   (merge 68cabbfda3 dl/doc-submodule-wo-subcommand later to maint).
   (merge 9903623761 ab/receive-pack-use-after-free-fix later to maint).
   (merge 1ede45e44b en/merge-options-doc later to maint).
   (merge 3e14dd2c8e rd/doc-hook-used-in-sample later to maint).
   (merge c271dc28fd nd/no-more-check-racy later to maint).
   (merge e6e15194a8 yb/utf-16le-bom-spellfix later to maint).
   (merge bb101aaf0c rd/attr.c-comment-typofix later to maint).
   (merge 716a5af812 rd/gc-prune-doc-fix later to maint).
   (merge 50b206371d js/untravis-windows later to maint).
   (merge dbf47215e3 js/rebase-recreate-merge later to maint).
   (merge 56cb2d30f8 dl/reset-doc-no-wrt-abbrev later to maint).
   (merge 64eca306a2 ja/dir-rename-doc-markup-fix later to maint).
   (merge af91b0230c dl/ignore-docs later to maint).
   (merge 59a06e947b ra/t3600-test-path-funcs later to maint).
   (merge e041d0781b ar/t4150-remove-cruft later to maint).