ancestor discovery during the "git fetch" transaction.
(merge 42cc7485a2 jt/fetch-negotiator-skipping later to maint).
+ * A new configuration variable core.usereplacerefs has been added,
+ primarily to help server installations that want to ignore the
+ replace mechanism altogether.
+
+ * Teach "git tag -s" etc. a few configuration variables (gpg.format
+ that can be set to "openpgp" or "x509", and gpg.<format>.program
+ that is used to specify what program to use to deal with the format)
+ to allow x.509 certs with CMS via "gpgsm" to be used instead of
+ openpgp via "gnupg".
+
+ * Many more strings are prepared for l10n.
+
+ * "git p4 submit" learns to ask its own pre-submit hook if it should
+ continue with submitting.
+
+ * The test performed at the receiving end of "git push" to prevent
+ bad objects from entering repository can be customized via
+ receive.fsck.* configuration variables; we now have gained a
+ counterpart to do the same on the "git fetch" side, with
+ fetch.fsck.* configuration variables.
+
+ * "git pull --rebase=interactive" learned "i" as a short-hand for
+ "interactive".
+
+ * "git instaweb" has been adjusted to run better with newer Apache on
+ RedHat based distros.
+
+ * "git range-diff" is a reimplementation of "git tbdiff" that lets us
+ compare individual patches in two iterations of a topic.
+
+ * The sideband code learned to optionally paint selected keywords at
+ the beginning of incoming lines on the receiving end.
+
Performance, Internal Implementation, Development Support etc.
* The singleton commit-graph in-core instance is made per in-core
repository instance.
+ * "make DEVELOPER=1 DEVOPTS=pedantic" allows developers to compile
+ with -pedantic option, which may catch more problematic program
+ constructs and potential bugs.
+
+ * Preparatory code to later add json output for telemetry data has
+ been added.
+
+ * Update the way we use Coccinelle to find out-of-style code that
+ need to be modernised.
+
+ * It is too easy to misuse system API functions such as strcat();
+ these selected functions are now forbidden in this codebase and
+ will cause a compilation failure.
+
+ * Add a script (in contrib/) to help users of VSCode work better with
+ our codebase.
+
+ * The Travis CI scripts were taught to ship back the test data from
+ failed tests.
+ (merge aea8879a6a sg/travis-retrieve-trash-upon-failure later to maint).
+
+ * The parse-options machinery learned to refrain from enclosing
+ placeholder string inside a "<bra" and "ket>" pair automatically
+ without PARSE_OPT_LITERAL_ARGHELP. Existing help text for option
+ arguments that are not formatted correctly have been identified and
+ fixed.
+ (merge 5f0df44cd7 rs/parse-opt-lithelp later to maint).
+
+ * Noiseword "extern" has been removed from function decls in the
+ header files.
+
+ * A few atoms like %(objecttype) and %(objectsize) in the format
+ specifier of "for-each-ref --format=<format>" can be filled without
+ getting the full contents of the object, but just with the object
+ header. These cases have been optimized by calling
+ oid_object_info() API (instead of reading and inspecting the data).
+
+ * The end result of documentation update has been made to be
+ inspected more easily to help developers.
+
+ * The API to iterate over all objects learned to optionally list
+ objects in the order they appear in packfiles, which helps locality
+ of access if the caller accesses these objects while as objects are
+ enumerated.
+
+ * Improve built-in facility to catch broken &&-chain in the tests.
+
+ * The more library-ish parts of the codebase learned to work on the
+ in-core index-state instance that is passed in by their callers,
+ instead of always working on the singleton "the_index" instance.
+
+ * A test prerequisite defined by various test scripts with slightly
+ different semantics has been consolidated into a single copy and
+ made into a lazily defined one.
+ (merge 6ec633059a wc/make-funnynames-shared-lazy-prereq later to maint).
+
+ * After a partial clone, repeated fetches from promisor remote would
+ have accumulated many packfiles marked with .promisor bit without
+ getting them coalesced into fewer packfiles, hurting performance.
+ "git repack" now learned to repack them.
+
Fixes since v2.18
-----------------
* The lazy clone support had a few places where missing but promised
objects were not correctly tolerated, which have been fixed.
+ * One of the "diff --color-moved" mode "dimmed_zebra" that was named
+ in an unusual way has been deprecated and replaced by
+ "dimmed-zebra".
+ (merge e3f2f5f9cd es/diff-color-moved-fix later to maint).
+
+ * The wire-protocol v2 relies on the client to send "ref prefixes" to
+ limit the bandwidth spent on the initial ref advertisement. "git
+ clone" when learned to speak v2 forgot to do so, which has been
+ corrected.
+ (merge 402c47d939 bw/clone-ref-prefixes later to maint).
+
+ * "git diff --histogram" had a bad memory usage pattern, which has
+ been rearranged to reduce the peak usage.
+ (merge 79cb2ebb92 sb/histogram-less-memory later to maint).
+
+ * Code clean-up to use size_t/ssize_t when they are the right type.
+ (merge 7726d360b5 jk/size-t later to maint).
+
+ * The wire-protocol v2 relies on the client to send "ref prefixes" to
+ limit the bandwidth spent on the initial ref advertisement. "git
+ fetch $remote branch:branch" that asks tags that point into the
+ history leading to the "branch" automatically followed sent to
+ narrow prefix and broke the tag following, which has been fixed.
+ (merge 2b554353a5 jt/tag-following-with-proto-v2-fix later to maint).
+
+ * When the sparse checkout feature is in use, "git cherry-pick" and
+ other mergy operations lost the skip_worktree bit when a path that
+ is excluded from checkout requires content level merge, which is
+ resolved as the same as the HEAD version, without materializing the
+ merge result in the working tree, which made the path appear as
+ deleted. This has been corrected by preserving the skip_worktree
+ bit (and not materializing the file in the working tree).
+ (merge 2b75fb601c en/merge-recursive-skip-fix later to maint).
+
+ * The "author-script" file "git rebase -i" creates got broken when
+ we started to move the command away from shell script, which is
+ getting fixed now.
+ (merge 5522bbac20 es/rebase-i-author-script-fix later to maint).
+
+ * The automatic tree-matching in "git merge -s subtree" was broken 5
+ years ago and nobody has noticed since then, which is now fixed.
+ (merge 2ec4150713 jk/merge-subtree-heuristics later to maint).
+
+ * "git fetch $there refs/heads/s" ought to fetch the tip of the
+ branch 's', but when "refs/heads/refs/heads/s", i.e. a branch whose
+ name is "refs/heads/s" exists at the same time, fetched that one
+ instead by mistake. This has been corrected to honor the usual
+ disambiguation rules for abbreviated refnames.
+ (merge 60650a48c0 jt/refspec-dwim-precedence-fix later to maint).
+
+ * Futureproofing a helper function that can easily be misused.
+ (merge 65bb21e77e es/want-color-fd-defensive later to maint).
+
+ * The http-backend (used for smart-http transport) used to slurp the
+ whole input until EOF, without paying attention to CONTENT_LENGTH
+ that is supplied in the environment and instead expecting the Web
+ server to close the input stream. This has been fixed.
+ (merge eebfe40962 mk/http-backend-content-length later to maint).
+
+ * "git merge --abort" etc. did not clean things up properly when
+ there were conflicted entries in the index in certain order that
+ are involved in D/F conflicts. This has been corrected.
+ (merge ad3762042a en/abort-df-conflict-fixes later to maint).
+
+ * "git diff --indent-heuristic" had a bad corner case performance.
+ (merge 301ef85401 sb/indent-heuristic-optim later to maint).
+
+ * The "--exec" option to "git rebase --rebase-merges" placed the exec
+ commands at wrong places, which has been corrected.
+
+ * "git verify-tag" and "git verify-commit" have been taught to use
+ the exit status of underlying "gpg --verify" to signal bad or
+ untrusted signature they found.
+ (merge 4e5dc9ca17 jc/gpg-status later to maint).
+
+ * "git mergetool" stopped and gave an extra prompt to continue after
+ the last path has been handled, which did not make much sense.
+ (merge d651a54b8a ng/mergetool-lose-final-prompt later to maint).
+
+ * Among the three codepaths we use O_APPEND to open a file for
+ appending, one used for writing GIT_TRACE output requires O_APPEND
+ implementation that behaves sensibly when multiple processes are
+ writing to the same file. POSIX emulation used in the Windows port
+ has been updated to improve in this area.
+ (merge d641097589 js/mingw-o-append later to maint).
+
+ * "git pull --rebase -v" in a repository with a submodule barfed as
+ an intermediate process did not understand what "-v(erbose)" flag
+ meant, which has been fixed.
+ (merge e84c3cf3dc sb/pull-rebase-submodule later to maint).
+
+ * Recent update to "git config" broke updating variable in a
+ subsection, which has been corrected.
+ (merge bff7df7a87 sb/config-write-fix later to maint).
+
+ * When "git rebase -i" is told to squash two or more commits into
+ one, it labeled the log message for each commit with its number.
+ It correctly called the first one "1st commit", but the next one
+ was "commit #1", which was off-by-one. This has been corrected.
+ (merge dd2e36ebac pw/rebase-i-squash-number-fix later to maint).
+
+ * "git rebase -i", when a 'merge <branch>' insn in its todo list
+ fails, segfaulted, which has been (minimally) corrected.
+ (merge bc9238bb09 pw/rebase-i-merge-segv-fix later to maint).
+
+ * "git cherry-pick --quit" failed to remove CHERRY_PICK_HEAD even
+ though we won't be in a cherry-pick session after it returns, which
+ has been corrected.
+ (merge 3e7dd99208 nd/cherry-pick-quit-fix later to maint).
+
* Code cleanup, docfix, build fix, etc.
(merge aee9be2ebe sg/update-ref-stdin-cleanup later to maint).
(merge 037714252f jc/clean-after-sanity-tests later to maint).
(merge 6aaded5509 tb/config-default later to maint).
(merge 022d2ac1f3 sb/blame-color later to maint).
(merge 5a06a20e0c bp/test-drop-caches-for-windows later to maint).
+ (merge dd61cc1c2e jk/ui-color-always-to-auto later to maint).
+ (merge 1e83b9bfdd sb/trailers-docfix later to maint).
+ (merge ab29f1b329 sg/fast-import-dump-refs-on-checkpoint-fix later to maint).
+ (merge 6a8ad880f0 jn/subtree-test-fixes later to maint).
+ (merge ffbd51cc60 nd/pack-objects-threading-doc later to maint).
+ (merge e9dac7be60 es/mw-to-git-chain-fix later to maint).
+ (merge fe583c6c7a rs/remote-mv-leakfix later to maint).
+ (merge 69885ab015 en/t3031-title-fix later to maint).
+ (merge 8578037bed nd/config-blame-sort later to maint).
+ (merge 8ad169c4ba hn/config-in-code-comment later to maint).
+ (merge b7446fcfdf ar/t4150-am-scissors-test-fix later to maint).
+ (merge a8132410ee js/typofixes later to maint).
+ (merge 388d0ff6e5 en/update-index-doc later to maint).
+ (merge e05aa688dd jc/update-index-doc later to maint).
+ (merge 10c600172c sg/t5310-empty-input-fix later to maint).
+ (merge 5641eb9465 jh/partial-clone-doc later to maint).
+ (merge 2711b1ad5e ab/submodule-relative-url-tests later to maint).