Git 2.28 Release Notes
======================

Updates since v2.27
-------------------

Backward compatibility notes

 * "feature.experimental" configuration variable is to let volunteers
   easily opt into a set of newer features, which use of the v2
   transport protocol is now a part of.

 * It used to be that setting extensions.* configuration variables
   alone, while leaving core.repositoryFormatVersion=0, made these
   settings effective, which was a wrong thing to do.  In version 0,
   there was no special meaning in extensions.* configuration
   variables.  This has been corrected.  If you need these repository
   extensions to be effective, the core.repositoryFormatVersion
   variable needs to be updated to 1 after vetting these extensions.*
   variables are set correctly.


UI, Workflows & Features

 * The commands in the "diff" family learned to honor "diff.relative"
   configuration variable.

 * The check in "git fsck" to ensure that the tree objects are sorted
   still had corner cases it missed unsorted entries.

 * The interface to redact sensitive information in the trace output
   has been simplified.

 * The command line completion (in contrib/) learned to complete
   options that the "git switch" command takes.

 * "git diff" used to take arguments in random and nonsense range
   notation, e.g. "git diff A..B C", "git diff A..B C...D", etc.,
   which has been cleaned up.

 * "git diff-files" has been taught to say paths that are marked as
   intent-to-add are new files, not modified from an empty blob.


Performance, Internal Implementation, Development Support etc.

 * Code optimization for a common case.
   (merge 8777616e4d an/merge-single-strategy-optim later to maint).

 * We've adopted a convention that any on-stack structure can be
   initialized to have zero values in all fields with "= { 0 }",
   even when the first field happens to be a pointer, but sparse
   complained that a null pointer should be spelled NULL for a long
   time.  Start using -Wno-universal-initializer option to squelch
   it (the latest sparse has it on by default).

 * "git log -L..." now takes advantage of the "which paths are touched
   by this commit?" info stored in the commit-graph system.

 * As FreeBSD is not the only platform whose regexp library reports
   a REG_ILLSEQ error when fed invalid UTF-8, add logic to detect that
   automatically and skip the affected tests.

 * "git bugreport" learns to report what shell is in use.

 * Support for GIT_CURL_VERBOSE has been rewritten in terms of
   GIT_TRACE_CURL.

 * Preliminary clean-ups around refs API, plus file format
   specification documentation for the reftable backend.

 * Workaround breakage in MSVC build, where "curl-config --cflags"
   gives settings appropriate for GCC build.

 * Code clean-up of "git clean" resulted in a fix of recent
   performance regression.

 * Code clean-up in the codepath that serves "git fetch" continues.

 * "git merge-base --is-ancestor" is taught to take advantage of the
   commit graph.

 * Rewrite of parts of the scripted "git submodule" Porcelain command
   continues; this time it is "git submodule set-branch" subcommand's
   turn.

 * The "fetch/clone" protocol has been updated to allow the server to
   instruct the clients to grab pre-packaged packfile(s) in addition
   to the packed object data coming over the wire.

 * A misdesigned strbuf_write_fd() function has been retired.


Fixes since v2.27
-----------------

 * The "--prepare-p4-only" option of "git p4" is supposed to stop
   after replaying one changeset, but kept going (by mistake?)

 * The error message from "git checkout -b foo -t bar baz" was
   confusing.

 * Some repositories in the wild have commits that record nonsense
   committer timezone (e.g. rails.git); "git fast-import" learned an
   option to pass these nonsense timestamps intact to allow recreating
   existing repositories as-is.
   (merge d42a2fb72f en/fast-import-looser-date later to maint).

 * The command line completion script (in contrib/) tried to complete
   "git stash -p" as if it were "git stash push -p", but it was too
   aggressive and also affected "git stash show -p", which has been
   corrected.
   (merge fffd0cf520 vs/complete-stash-show-p-fix later to maint).

 * On-the-wire protocol v2 easily falls into a deadlock between the
   remote-curl helper and the fetch-pack process when the server side
   prematurely throws an error and disconnects.  The communication has
   been updated to make it more robust.

 * "git checkout -p" did not handle a newly added path at all.
   (merge 2c8bd8471a js/checkout-p-new-file later to maint).

 * The code to parse "git bisect start" command line was lax in
   validating the arguments.
   (merge 4d9005ff5d cb/bisect-helper-parser-fix later to maint).

 * Reduce memory usage during "diff --quiet" in a worktree with too
   many stat-unmatched paths.
   (merge d2d7fbe129 jk/diff-memuse-optim-with-stat-unmatch later to maint).

 * The reflog entries for "git clone" and "git fetch" did not
   anonymize the URL they operated on.
   (merge 46da295a77 js/reflog-anonymize-for-clone-and-fetch later to maint).

 * The behaviour of "sparse-checkout" in the state "git clone
   --no-checkout" left was changed accidentally in 2.27, which has
   been corrected.

 * Use of negative pathspec, while collecting paths including
   untracked ones in the working tree, was broken.

 * The same worktree directory must be registered only once, but
   "git worktree move" allowed this invariant to be violated, which
   has been corrected.
   (merge 810382ed37 es/worktree-duplicate-paths later to maint).

 * The effect of sparse checkout settings on submodules is documented.
   (merge e7d7c73249 en/sparse-with-submodule-doc later to maint).

 * Code clean-up around "git branch" with a minor bugfix.
   (merge dc44639904 dl/branch-cleanup later to maint).

 * A branch name used in a test has been clarified to match what is
   going on.
   (merge 08dc26061f pb/t4014-unslave later to maint).

 * An in-code comment in "git diff" has been updated.
   (merge c592fd4c83 dl/diff-usage-comment-update later to maint).

 * Other code cleanup, docfix, build fix, etc.
   (merge 2c31a7aa44 jx/pkt-line-doc-count-fix later to maint).
   (merge d63ae31962 cb/t5608-cleanup later to maint).
   (merge 788db145c7 dl/t-readme-spell-git-correctly later to maint).
   (merge 45a87a83bb dl/python-2.7-is-the-floor-version later to maint).
   (merge b75a219904 es/advertise-contribution-doc later to maint).
   (merge 0c9a4f638a rs/pull-leakfix later to maint).
   (merge d546fe2874 rs/commit-reach-leakfix later to maint).