"git log" by default enables the rename detection; you can still use
"diff.renames" configuration variable to disable this.
+Merging two branches that have no common ancestor with "git merge" is
+by default forbidden now to prevent creating such an unusual merge by
+mistake.
+
+The output formats of "git log" that indents the commit log message by
+4 spaces now expands HT in the log message by default. You can use
+the "--no-expand-tabs" option to disable this.
+
Updates since v2.8
------------------
* A new "interactive.diffFilter" configuration can be used to
customize the diff shown in "git add -i" session.
+ * "git p4" now allows P4 author names to be mapped to Git author
+ names.
+
+ * "git rebase -x" can be used without passing "-i" option.
+
+ * "git -c credential.<var>=<value> submodule" can now be used to
+ propagate configuration variables related to credential helper
+ down to the submodules.
+
+ * "git tag" can create an annotated tag without explicitly given an
+ "-a" (or "-s") option (i.e. when a tag message is given). A new
+ configuration variable, tag.forceSignAnnotated, can be used to tell
+ the command to create signed tag in such a situation.
+
+ * "git merge" used to allow merging two branches that have no common
+ base by default, which led to a brand new history of an existing
+ project created and then get pulled by an unsuspecting maintainer,
+ which allowed an unnecessary parallel history merged into the
+ existing project. The command has been taught not to allow this by
+ default, with an escape hatch "--allow-unrelated-histories" option
+ to be used in a rare event that merges histories of two projects
+ that started their lives independently.
+
+ * "git apply -v" learned to report paths in the patch that were
+ skipped via --include/--exclude mechanism or being outside the
+ current working directory.
+
+ * Shell completion (in contrib/) updates.
+
+ * The commit object name reported when "rebase -i" stops has been
+ shortened.
+
+ * "git worktree add" can be given "--no-checkout" option to only
+ create an empty worktree without checking out the files.
+
+ * "git mergetools" learned to drive ExamDiff.
+
+ * "git pull --rebase" learned "--[no-]autostash" option, so that
+ the rebase.autostash configuration variable set to true can be
+ overridden from the command line.
+
+ * When "git log" shows the log message indented by 4-spaces, the
+ remainder of a line after a HT does not align in the way the author
+ originally intended. The command now expands tabs by default in
+ such a case, and allows the users to override it with a new option,
+ "--no-expand-tabs".
+
Performance, Internal Implementation, Development Support etc.
* A test for tags has been restructured so that more parts of it can
easily be run on a platform without a working GnuPG.
- (merge 618310a es/test-gpg-tags later to maint).
* The startup_info data, which records if we are working inside a
repository (among other things), are now uniformly available to Git
references when we are not in a repository.
(merge 11e6b3f jk/startup-info later to maint).
+ * The command line argument parser for "receive-pack" has been
+ rewritten to use parse-options.
+
+ * A major part of "git submodule update" has been ported to C to take
+ advantage of the recently added framework to run download tasks in
+ parallel.
+
+ * Rename bunch of tests on "git clone" for better organization.
+ (merge 8fbb03a sb/clone-t57-t56 later to maint).
+
+ * The tests that involve running httpd leaked the system-wide
+ configuration in /etc/gitconfig to the tested environment.
+ (merge 1fad503 jk/test-httpd-config-nosystem later to maint).
+
+ * Build updates for MSVC.
+ (merge 0ef60af ss/msvc later to maint).
+
+ * The repository set-up sequence has been streamlined (the biggest
+ change is that there is no longer git_config_early()), so that we
+ do not attempt to look into refs/* when we know we do not have a
+ Git repository.
+ (merge 274db84 jk/check-repository-format later to maint).
+
Also contains various documentation updates and code clean-ups.
corner cases in its error codepath.
(merge b709043 jk/getwholeline-getdelim-empty later to maint).
+ * "git mergetool" did not work well with conflicts that both sides
+ deleted.
+ (merge a298604 da/mergetool-delete-delete-conflict later to maint).
+
+ * "git send-email" had trouble parsing alias file in mailrc format
+ when lines in it had trailing whitespaces on them.
+ (merge a277d1e jk/send-email-rtrim-mailrc-alias later to maint).
+
+ * When "git merge --squash" stopped due to conflict, the concluding
+ "git commit" failed to read in the SQUASH_MSG that shows the log
+ messages from all the squashed commits.
+ (merge b64c1e0 ss/commit-squash-msg later to maint).
+
+ * "git merge FETCH_HEAD" dereferenced NULL pointer when merging
+ nothing into an unborn history (which is arguably unusual usage,
+ which perhaps was the reason why nobody noticed it).
+ (merge b84e65d jv/merge-nothing-into-void later to maint).
+
+ * When "git worktree" feature is in use, "git branch -d" allowed
+ deletion of a branch that is checked out in another worktree,
+ which was wrong.
+ (merge f292244 ky/branch-d-worktree later to maint).
+
+ * When "git worktree" feature is in use, "git branch -m" renamed a
+ branch that is checked out in another worktree without adjusting
+ the HEAD symbolic ref for the worktree.
+ (merge 18eb3a9 ky/branch-m-worktree later to maint).
+
+ * "git diff -M" used to work better when two originally identical
+ files A and B got renamed to X/A and X/B by pairing A to X/A and B
+ to X/B, but this was broken in the 2.0 timeframe.
+ (merge ca4e3ca sg/diff-multiple-identical-renames later to maint).
+
+ * "git send-pack --all <there>" was broken when its command line
+ option parsing was written in the 2.6 timeframe.
+ (merge c677756 sk/send-pack-all-fix later to maint).
+
+ * "git format-patch --help" showed `-s` and `--no-patch` as if these
+ are valid options to the command. We already hide `--patch` option
+ from the documentation, because format-patch is about showing the
+ diff, and the documentation now hides these options as well.
+ (merge b73a1bc es/format-patch-doc-hide-no-patch later to maint).
+
+ * When running "git blame $path" with unnormalized data in the index
+ for the path, the data in the working tree was blamed, even though
+ "git add" would not have changed what is already in the index, due
+ to "safe crlf" that disables the line-end conversion. It has been
+ corrected.
+ (merge a08feb8 tb/blame-force-read-cache-to-workaround-safe-crlf later to maint).
+
+ * A change back in version 2.7 to "git branch" broke display of a
+ symbolic ref in a non-standard place in the refs/ hierarchy (we
+ expect symbolic refs to appear in refs/remotes/*/HEAD to point at
+ the primary branch the remote has, and as .git/HEAD to point at the
+ branch we locally checked out).
+ (merge 95c38fb jk/branch-shortening-funny-symrefs later to maint).
+
* Other minor clean-ups and documentation updates
(merge aed7480 mm/lockfile-error-message later to maint).
(merge bfee614 jc/index-pack later to maint).
+ (merge f870899 ss/exc-flag-is-a-collection-of-bits later to maint).
+ (merge dde7891 pb/t7502-drop-dup later to maint).
+ (merge 3bd1b51 cc/doc-recommend-performance-trace-to-file later to maint).
+ (merge 7d5e9c9 jk/credential-cache-comment-exit later to maint).
+ (merge 16a86d4 nd/apply-doc later to maint).
+ (merge c3f6b85 pb/opt-cmdmode-doc later to maint).
+ (merge 30211fb oa/doc-diff-check later to maint).
+ (merge 01d98e8 ak/use-hashmap-iter-first-in-submodule-config later to maint).
+ (merge 8b5a3e9 kn/for-each-tag-branch later to maint).
+ (merge 9c60d9f sb/misc-cleanups later to maint).
+ (merge 7a6a44c cc/apply later to maint).
+ (merge 8e9b208 js/mingw-tests-2.8 later to maint).
+ (merge d55de70 jc/makefile-redirection-stderr later to maint).
+ (merge 4232b21 ep/trace-doc-sample-fix later to maint).