Git v2.52 Release Notes
=======================

UI, Workflows & Features
------------------------

 * The "list" subcommand of "git refs" acts as a front-end for
   "git for-each-ref".

 * "git cmd --help-all" now works outside repositories.

 * "git diff-tree" learned "--max-depth" option.

 * A new subcommand "git repo" gives users a way to grab various
   repository characteristics.

 * A new command "git last-modified" has been added to show the closest
   ancestor commit that touched each path.

 * "git refs exists" that works like "git show-ref --exists" has been
   added.

 * "repo info" learns a short-hand option "-z" that is the same as
   "--format=nul", and learns to report the objects format used in the
   repository.

 * "core.commentChar=auto" that attempts to dynamically pick a
   suitable comment character is non-workable, as it is too much
   trouble to support for little benefit, and is marked as deprecated.

 * "git send-email" learned to drive "git imap-send" to store already
   sent e-mails in an IMAP folder.

 * The "promisor-remote" capability mechanism has been updated to
   allow the "partialCloneFilter" settings and the "token" value to be
   communicated from the server side.


Performance, Internal Implementation, Development Support etc.
--------------------------------------------------------------

 * string_list_split*() family of functions have been extended to
   simplify common use cases.

 * Arrays of strbuf is often a wrong data structure to use, and
   strbuf_split*() family of functions that create them often have
   better alternatives.  Update several code paths and replace
   strbuf_split*().

 * Revision traversal limited with pathspec, like "git log dir/*",
   used to ignore changed-paths Bloom filter when the pathspec
   contained wildcards; now they take advantage of the filter when
   they can.

 * Doc lint updates to encourage the newer and easier-to-use
   `synopsis` format, with fixes to a handful of existing uses.

 * Remove dependency on the_repository and other globals from the
   commit-graph code, and other changes unrelated to de-globaling.

 * Discord has been added to the first contribution documentation as
   another way to ask for help.

 * Inspired by Ezekiel's recent effort to showcase Rust interface, the
   hash function implementation used to hash lines have been updated
   to the one used for ELF symbol lookup by Glibc.

 * Instead of scanning for the remaining items to see if there are
   still commits to be explored in the queue, use khash to remember
   which items are still on the queue (an unacceptable alternative is
   to reserve one object flag bits).

 * The bulk-checkin code used to depend on a file-scope static
   singleton variable, which has been updated to pass an instance
   throughout the callchain.

 * CodingGuidelines now spells out how bitfields are to be written.

 * Adjust to the way newer versions of cURL selectivel enables tracing
   options, so that our tests can continue to work.
   (merge 1b5a6bfff3 jk/curl-global-trace-components later to maint).

 * The clear_alloc_state() API function was not fully clearing the
   structure for reuse, but since nobody reuses it, replace it with a
   variant that frees the structure as well, making the callers simpler.

 * "git range-diff" learned a way to limit the memory consumed by
   O(N*N) cost matrix.


Fixes since v2.51
-----------------

Unless otherwise noted, all the changes in 2.51.X maintenance track,
including security updates, are included in this release.

 * During interactive rebase, using 'drop' on a merge commit lead to
   an error, which was incorrect.
   (merge 4d491ade8f js/rebase-i-allow-drop-on-a-merge later to maint).

 * "git refs migrate" to migrate the reflog entries from a refs
   backend to another had a handful of bugs squashed.
   (merge 465eff81de ps/reflog-migrate-fixes later to maint).

 * "git remote rename origin upstream" failed to move origin/HEAD to
   upstream/HEAD when origin/HEAD is unborn and performed other
   renames extremely inefficiently, which has been corrected.
   (merge 16c4fa26b9 ps/remote-rename-fix later to maint).

 * "git describe" has been optimized by using better data structure.
   (merge 08bb69d70f rs/describe-with-prio-queue later to maint).

 * "git push" had a code path that led to BUG() but it should have
   been a die(), as it is a response to a usual but invalid end-user
   action to attempt pushing an object that does not exist.
   (merge dfbfc2221b dl/push-missing-object-error later to maint).

 * Various bugs about rename handling in "ort" merge strategy have
   been fixed.
   (merge f6ecb603ff en/ort-rename-fixes later to maint).

 * "git jump" (in contrib/) fails to parse the diff header correctly
   when a file has a space in its name, which has been corrected.
   (merge 621ce9c1c6 gh/git-jump-pathname-with-sp later to maint).

 * "git diff --no-index" run inside a subdirectory under control of a
   Git repository operated at the top of the working tree and stripped
   the prefix from the output, and oddballs like "-" (stdin) did not
   work correctly because of it.  Correct the set-up by undoing what
   the set-up sequence did to cwd and prefix.
   (merge e1d3d61a45 jc/diff-no-index-in-subdir later to maint).

 * Various options to "git diff" that makes comparison ignore certain
   aspects of the differences (like "space changes are ignored",
   "differences in lines that match these regular expressions are
   ignored") did not work well with "--name-only" and friends.
   (merge b55e6d36eb ly/diff-name-only-with-diff-from-content later to maint).

 * Documentation for "git rebase" has been updated.
   (merge 3f7f2b0359 je/doc-rebase later to maint).

 * The start_delayed_progress() function in the progress eye-candy API
   did not clear its internal state, making an initial delay value
   larger than 1 second ineffective, which has been corrected.
   (merge 457534d041 js/progress-delay-fix later to maint).

 * The compatObjectFormat extension is used to hide an incomplete
   feature that is not yet usable for any purpose other than
   developing the feature further.  Document it as such to discourage
   its use by mere mortals.
   (merge 716d905792 bc/doc-compat-object-format-not-working later to maint).

 * "git log -L..." compared trees of multiple parents with the tree of the
   merge result in an unnecessarily inefficient way.
   (merge 0a15bb634c sg/line-log-merge-optim later to maint).

 * Under a race against another process that is repacking the
   repository, especially a partially cloned one, "git fetch" may
   mistakenly think some objects we do have are missing, which has
   been corrected.
   (merge 8f32a5a6c0 jk/fetch-check-graph-objects-fix later to maint).

 * "git fetch" can clobber a symref that is dangling when the
   remote-tracking HEAD is set to auto update, which has been
   corrected.

 * "git describe <blob>" misbehaves and/or crashes in some corner
   cases, which has been taught to exit with failure gracefully.
   (merge 7c10e48e81 jk/describe-blob later to maint).

 * Manual page for "gitk" is updated with the current maintainer's
   name.
   (merge bcb20dda83 js/doc-gitk-history later to maint).

 * Update the instruction to use of GGG in the MyFirstContribution
   document to say that a GitHub PR could be made against `git/git`
   instead of `gitgitgadget/git`.
   (merge 37001cdbc4 ds/doc-ggg-pr-fork-clarify later to maint).

 * Makefile tried to run multiple "cargo build" which would not work
   very well; serialize their execution to work it around.
   (merge 0eeacde50e da/cargo-serialize later to maint).

 * "git repack --path-walk" lost objects in some corner cases, which
   has been corrected.
   (merge 93afe9b060 ds/path-walk-repack-fix later to maint).

 * "git ls-files <pathspec>..." should not necessarily have to expand
   the index fully if a sparsified directory is excluded by the
   pathspec; the code is taught to expand the index on demand to avoid
   this.
   (merge 681f26bccc ds/ls-files-lazy-unsparse later to maint).

 * Windows "real-time monitoring" interferes with the execution of
   tests and affects negatively in both correctness and performance,
   which has been disabled in Gitlab CI.
   (merge 608cf5b793 ps/gitlab-ci-disable-windows-monitoring later to maint).

 * A broken or malicious "git fetch" can say that it has the same
   object for many many times, and the upload-pack serving it can
   exhaust memory storing them redundantly, which has been corrected.
   (merge 88a2dc68c8 ps/upload-pack-oom-protection later to maint).

 * A corner case bug in "git log -L..." has been corrected.
   (merge e3106998ff sg/line-log-boundary-fixes later to maint).

 * "git rev-parse --short" and friends failed to disambiguate two
   objects with object names that share common prefix longer than 32
   characters, which has been fixed.
   (merge 8655908b9e jc/longer-disambiguation-fix later to maint).

 * Some among "git add -p" and friends ignored color.diff and/or
   color.ui configuration variables, which is an old regression, which
   has been corrected.
   (merge 1092cd6435 jk/add-i-color later to maint).

 * "git subtree" (in contrib/) did not work correctly when splitting
   squashed subtrees, which has been improved.

 * Other code cleanup, docfix, build fix, etc.
   (merge 823d537fa7 kh/doc-git-log-markup-fix later to maint).
   (merge cf7efa4f33 rj/t6137-cygwin-fix later to maint).
   (merge 529a60a885 ua/t1517-short-help-tests later to maint).
   (merge 22d421fed9 ac/deglobal-fmt-merge-log-config later to maint).
   (merge 741f36c7d9 kr/clone-synopsis-fix later to maint).
   (merge a60203a015 dk/t7005-editor-updates later to maint).
   (merge 7d4a5fef7d ds/doc-count-objects-fix later to maint).
   (merge 16684b6fae ps/reftable-libgit2-cleanup later to maint).
   (merge f38786baa7 ja/asciidoc-doctor-verbatim-fixes later to maint).
   (merge 374579c6d4 kh/doc-interpret-trailers-markup-fix later to maint).
   (merge 44dce6541c kh/doc-config-typofix later to maint).
   (merge 785628b173 js/doc-sending-patch-via-thunderbird later to maint).
   (merge e5c27bd3d8 je/doc-add later to maint).
   (merge 13296ac909 ps/object-store-midx-dedup-info later to maint).
   (merge 2f4bf83ffc km/alias-doc-markup-fix later to maint).
   (merge b0d97aac19 kh/doc-markup-fixes later to maint).
   (merge f9a6705d9a tc/t0450-harden later to maint).
   (merge c25651aefd ds/midx-write-fixes later to maint).
   (merge 069c15d256 rs/object-name-extend-abbrev-len-update later to maint).
   (merge bf5c224537 mm/worktree-doc-typofix later to maint).
   (merge 31397bc4f7 kh/doc-fast-import-markup-fix later to maint).
   (merge ac7096723b jc/doc-includeif-hasconfig-remote-url-fix later to maint).
   (merge fafc9b08b8 ag/doc-sendmail-gmail-example-update later to maint).
   (merge a66fc22bf9 rs/get-oid-with-flags-cleanup later to maint).
