git/Documentation/RelNotes/2.15.0.txt

Git 2.15 Release Notes
======================

Backward compatibility notes and other notable changes.

 * Use of an empty string as a pathspec element that is used for
   'everything matches' is still warned and Git asks users to use a
   more explicit '.' for that instead.  The hope is that existing
   users will not mind this change, and eventually the warning can be
   turned into a hard error, upgrading the deprecation into removal of
   this (mis)feature.  That is now scheduled to happen in the upcoming
   release.

 * Git now avoids blindly falling back to ".git" when the setup
   sequence said we are _not_ in Git repository.  A corner case that
   happens to work right now may be broken by a call to die("BUG").
   We've tried hard to locate such cases and fixed them, but there
   might still be cases that need to be addressed--bug reports are
   greatly appreciated.

 * "branch --set-upstream" that has been deprecated in Git 1.8 has
   finally been retired.


Updates since v2.14
-------------------

UI, Workflows & Features

 * An example that is now obsolete has been removed from a sample hook,
   and an old example in it that added a sign-off manually has been
   improved to use the interpret-trailers command.

 * The advice message given when "git rebase" stops for conflicting
   changes has been improved.

 * The "rerere-train" script (in contrib/) learned the "--overwrite"
   option to allow overwriting existing recorded resolutions.

 * "git contacts" (in contrib/) now lists the address on the
   "Reported-by:" trailer to its output, in addition to those on
   S-o-b: and other trailers, to make it easier to notify (and thank)
   the original bug reporter.

 * "git rebase", especially when it is run by mistake and ends up
   trying to replay many changes, spent long time in silence.  The
   command has been taught to show progress report when it spends
   long time preparing these many changes to replay (which would give
   the user a chance to abort with ^C).

 * "git merge" learned a "--signoff" option to add the Signed-off-by:
   trailer with the committer's name.

 * "git diff" learned to optionally paint new lines that are the same
   as deleted lines elsewhere differently from genuinely new lines.

 * "git interpret-trailers" learned to take the trailer specifications
   from the command line that overrides the configured values.

 * "git interpret-trailers" has been taught a "--parse" and a few
   other options to make it easier for scripts to grab existing
   trailer lines from a commit log message.

 * "gitweb" shows a link to visit the 'raw' contents of blbos in the
   history overview page.

 * "[gc] rerereResolved = 5.days" used to be invalid, as the variable
   is defined to take an integer counting the number of days.  It now
   is allowed.

 * The code to acquire a lock on a reference (e.g. while accepting a
   push from a client) used to immediately fail when the reference is
   already locked---now it waits for a very short while and retries,
   which can make it succeed if the lock holder was holding it during
   a read-only operation.

 * "branch --set-upstream" that has been deprecated in Git 1.8 has
   finally been retired.

 * The codepath to call external process filter for smudge/clean
   operation learned to show the progress meter.


Performance, Internal Implementation, Development Support etc.

 * Conversion from uchar[20] to struct object_id continues.

 * Start using selected c99 constructs in small, stable and
   essentialpart of the system to catch people who care about
   older compilers that do not grok them.

 * The filter-process interface learned to allow a process with long
   latency give a "delayed" response.

 * Many uses of comparision callback function the hashmap API uses
   cast the callback function type when registering it to
   hashmap_init(), which defeats the compile time type checking when
   the callback interface changes (e.g. gaining more parameters).
   The callback implementations have been updated to take "void *"
   pointers and cast them to the type they expect instead.

 * Because recent Git for Windows do come with a real msgfmt, the
   build procedure for git-gui has been updated to use it instead of a
   hand-rolled substitute.

 * "git grep --recurse-submodules" has been reworked to give a more
   consistent output across submodule boundary (and do its thing
   without having to fork a separate process).

 * A helper function to read a single whole line into strbuf
   mistakenly triggered OOM error at EOF under certain conditions,
   which has been fixed.
   (merge 642956cf45 rs/strbuf-getwholeline-fix later to maint).

 * The "ref-store" code reorganization continues.

 * "git commit" used to discard the index and re-read from the filesystem
   just in case the pre-commit hook has updated it in the middle; this
   has been optimized out when we know we do not run the pre-commit hook.
   (merge 680ee550d7 kw/commit-keep-index-when-pre-commit-is-not-run later to maint).

 * Updates to the HTTP layer we made recently unconditionally used
   features of libCurl without checking the existence of them, causing
   compilation errors, which has been fixed.  Also migrate the code to
   check feature macros, not version numbers, to cope better with
   libCurl that vendor ships with backported features.

 * The API to start showing progress meter after a short delay has
   been simplified.
   (merge 8aade107dd jc/simplify-progress later to maint).

 * Code clean-up to avoid mixing values read from the .gitmodules file
   and values read from the .git/config file.

 * We used to spend more than necessary cycles allocating and freeing
   piece of memory while writing each index entry out.  This has been
   optimized.

 * Platforms that ship with a separate sha1 with collision detection
   library can link to it instead of using the copy we ship as part of
   our source tree.

 * Code around "notes" have been cleaned up.
   (merge 3964281524 mh/notes-cleanup later to maint).

 * The long-standing rule that an in-core lockfile instance, once it
   is used, must not be freed, has been lifted and the lockfile and
   tempfile APIs have been updated to reduce the chance of programming
   errors.

 * Our hashmap implementation in hashmap.[ch] is not thread-safe when
   adding a new item needs to expand the hashtable by rehashing; add
   an API to disable the automatic rehashing to work it around.

 * Many of our programs consider that it is OK to release dynamic
   storage that is used throughout the life of the program by simply
   exiting, but this makes it harder to leak detection tools to avoid
   reporting false positives.  Plug many existing leaks and introduce
   a mechanism for developers to mark that the region of memory
   pointed by a pointer is not lost/leaking to help these tools.

 * As "git commit" to conclude a conflicted "git merge" honors the
   commit-msg hook, "git merge" that records a merge commit that
   cleanly auto-merges should, but it didn't.

 * The codepath for "git merge-recursive" has been cleaned up.

 * Many leaks of strbuf have been fixed.


Also contains various documentation updates and code clean-ups.


Fixes since v2.14
-----------------

 * "%C(color name)" in the pretty print format always produced ANSI
   color escape codes, which was an early design mistake.  They now
   honor the configuration (e.g. "color.ui = never") and also tty-ness
   of the output medium.

 * The http.{sslkey,sslCert} configuration variables are to be
   interpreted as a pathname that honors "~[username]/" prefix, but
   weren't, which has been fixed.

 * Numerous bugs in walking of reflogs via "log -g" and friends have
   been fixed.

 * "git commit" when seeing an totally empty message said "you did not
   edit the message", which is clearly wrong.  The message has been
   corrected.

 * When a directory is not readable, "gitweb" fails to build the
   project list.  Work this around by skipping such a directory.

 * Some versions of GnuPG fails to kill gpg-agent it auto-spawned
   and such a left-over agent can interfere with a test.  Work it
   around by attempting to kill one before starting a new test.

 * A recently added test for the "credential-cache" helper revealed
   that EOF detection done around the time the connection to the cache
   daemon is torn down were flaky.  This was fixed by reacting to
   ECONNRESET and behaving as if we got an EOF.

 * "git log --tag=no-such-tag" showed log starting from HEAD, which
   has been fixed---it now shows nothing.

 * The "tag.pager" configuration variable was useless for those who
   actually create tag objects, as it interfered with the use of an
   editor.  A new mechanism has been introduced for commands to enable
   pager depending on what operation is being carried out to fix this,
   and then "git tag -l" is made to run pager by default.

 * "git push --recurse-submodules $there HEAD:$target" was not
   propagated down to the submodules, but now it is.

 * Commands like "git rebase" accepted the --rerere-autoupdate option
   from the command line, but did not always use it.  This has been
   fixed.

 * "git clone --recurse-submodules --quiet" did not pass the quiet
   option down to submodules.

 * Test portability fix for OBSD.

 * Portability fix for OBSD.

 * "git am -s" has been taught that some input may end with a trailer
   block that is not Signed-off-by: and it should refrain from adding
   an extra blank line before adding a new sign-off in such a case.

 * "git svn" used with "--localtime" option did not compute the tz
   offset for the timestamp in question and instead always used the
   current time, which has been corrected.

 * Memory leak in an error codepath has been plugged.

 * "git stash -u" used the contents of the committed version of the
   ".gitignore" file to decide which paths are ignored, even when the
   file has local changes.  The command has been taught to instead use
   the locally modified contents.

 * bash 4.4 or newer gave a warning on NUL byte in command
   substitution done in "git stash"; this has been squelched.

 * "git grep -L" and "git grep --quiet -L" reported different exit
   codes; this has been corrected.

 * When handshake with a subprocess filter notices that the process
   asked for an unknown capability, Git did not report what program
   the offending subprocess was running.  This has been corrected.

 * "git apply" that is used as a better "patch -p1" failed to apply a
   taken from a file with CRLF line endings to a file with CRLF line
   endings.  The root cause was because it misused convert_to_git()
   that tried to do "safe-crlf" processing by looking at the index
   entry at the same path, which is a nonsense---in that mode, "apply"
   is not working on the data in (or derived from) the index at all.
   This has been fixed.

 * Killing "git merge --edit" before the editor returns control left
   the repository in a state with MERGE_MSG but without MERGE_HEAD,
   which incorrectly tells the subsequent "git commit" that there was
   a squash merge in progress.  This has been fixed.

 * "git archive" did not work well with pathspecs and the
   export-ignore attribute.

 * In addition to "cc: <a@dd.re.ss> # cruft", "cc: a@dd.re.ss # cruft"
   was taught to "git send-email" as a valid way to tell it that it
   needs to also send a carbon copy to <a@dd.re.ss> in the trailer
   section.
   (merge cc90750677 mm/send-email-cc-cruft later to maint).

 * "git branch -M a b" while on a branch that is completely unrelated
   to either branch a or branch b misbehaved when multiple worktree
   was in use.  This has been fixed.
   (merge 31824d180d nd/worktree-kill-parse-ref later to maint).

 * "git gc" and friends when multiple worktrees are used off of a
   single repository did not consider the index and per-worktree refs
   of other worktrees as the root for reachability traversal, making
   objects that are in use only in other worktrees to be subject to
   garbage collection.

 * A regression to "gitk --bisect" by a recent update has been fixed.
   (merge 1d0538e486 mh/packed-ref-store-prep later to maint).

 * "git -c submodule.recurse=yes pull" did not work as if the
   "--recurse-submodules" option was given from the command line.
   This has been corrected.

 * Unlike "git commit-tree < file", "git commit-tree -F file" did not
   pass the contents of the file verbatim and instead completed an
   incomplete line at the end, if exists.  The latter has been updated
   to match the behaviour of the former.
   (merge c818e74332 rk/commit-tree-make-F-verbatim later to maint).

 * Other minor doc, test and build updates and code cleanups.
   (merge f094b89a4d ma/parse-maybe-bool later to maint).
   (merge 39b00fa4d4 jk/drop-sha1-entry-pos later to maint).
   (merge 6cdf8a7929 ma/ts-cleanups later to maint).
   (merge 7560f547e6 ma/up-to-date later to maint).
   (merge 0db3dc75f3 rs/apply-epoch later to maint).
   (merge 74f1bd912b dw/diff-highlight-makefile-fix later to maint).
   (merge f991761eb8 jk/config-lockfile-leak-fix later to maint).
   (merge 150efef1e7 ma/pkt-line-leakfix later to maint).
   (merge 5554451de6 mg/timestamp-t-fix later to maint).
   (merge 276d0e35c0 ma/split-symref-update-fix later to maint).
   (merge 3bc4b8f7c7 bb/doc-eol-dirty later to maint).
   (merge c1bb33c99c jk/system-path-cleanup later to maint).