-Git Release Notes
-=================
+Git 2.20 Release Notes
+======================
Backward Compatibility Notes
----------------------------
* "git help -a" now gives verbose output (same as "git help -av").
Those who want the old output may say "git help --no-verbose -a"..
+ * "git cpn --help", when "cpn" is an alias to, say, "cherry-pick -n",
+ reported only the alias expansion of "cpn" in earlier versions of
+ Git. It now runs "git cherry-pick --help" to show the manual page
+ of the command, while sending the alias expansion to the standard
+ error stream.
+
+ * "git send-email" learned to grab address-looking string on any
+ trailer whose name ends with "-by". This is a backward-incompatible
+ change. Adding "--suppress-cc=misc-by" on the command line, or
+ setting sendemail.suppresscc configuration variable to "misc-by",
+ can be used to disable this behaviour.
+
Updates since v2.19
-------------------
* "git format-patch" learned new "--interdiff" and "--range-diff"
options to explain the difference between this version and the
- previous attempt in the cover letter (or after the tree-dashes as
+ previous attempt in the cover letter (or after the three-dashes as
a comment).
* "git mailinfo" used in "git am" learned to make a best-effort
meaningfully large repository. The users will now see progress
output.
- * The minimum version of Windows supported by Windows port fo Git is
+ * The minimum version of Windows supported by Windows port of Git is
now set to Vista.
* The completion script (in contrib/) learned to complete a handful of
advertisement. The alternate refs that are advertised are now
configurable with a pair of configuration variables.
+ * "git cmd --help" when "cmd" is aliased used to only say "cmd is
+ aliased to ...". Now it shows that to the standard error stream
+ and runs "git $cmd --help" where $cmd is the first word of the
+ alias expansion.
+
+ * The documentation of "git gc" has been updated to mention that it
+ is no longer limited to "pruning away crufts" but also updates
+ ancillary files like commit-graph as a part of repository
+ optimization.
+
+ * "git p4 unshelve" improvements.
+
+ * The logic to select the default user name and e-mail on Windows has
+ been improved.
+ (merge 501afcb8b0 js/mingw-default-ident later to maint).
+
+ * The "rev-list --filter" feature learned to exclude all trees via
+ "tree:0" filter.
+
+ * "git send-email" learned to grab address-looking string on any
+ trailer whose name ends with "-by"; --suppress-cc=misc-by on the
+ command line, or setting sendemail.suppresscc configuration
+ variable to "misc-by", can be used to disable this behaviour.
+
+ * "git mergetool" learned to take the "--[no-]gui" option, just like
+ "git difftool" does.
+
+ * "git rebase -i" learned a new insn, 'break', that the user can
+ insert in the to-do list. Upon hitting it, the command returns
+ control back to the user.
+
+ * New "--pretty=format:" placeholders %GF and %GP that show the GPG
+ key fingerprints have been invented.
+
+ * On platforms with recent cURL library, http.sslBackend configuration
+ variable can be used to choose a different SSL backend at runtime.
+ The Windows port uses this mechanism to switch between OpenSSL and
+ Secure Channel while talking over the HTTPS protocol.
+
+ * "git send-email" learned to disable SMTP authentication via the
+ "--smtp-auth=none" option, even when the smtp username is given
+ (which turns the authentication on by default).
+
+ * A fourth class of configuration files (in addition to the
+ traditional "system wide", "per user in the $HOME directory" and
+ "per repository in the $GIT_DIR/config") has been introduced so
+ that different worktrees that share the same repository (hence the
+ same $GIT_DIR/config file) can use different customization.
+
+ * A pattern with '**' that does not have a slash on either side used
+ to be an invalid one, but the code now treats such double-asterisks
+ the same way as two normal asterisks that happen to be adjacent to
+ each other.
+ (merge e5bbe09e88 nd/wildmatch-double-asterisk later to maint).
+
+ * The "--no-patch" option, which can be used to get a high-level
+ overview without the actual line-by-line patch difference shown, of
+ the "range-diff" command was earlier broken, which has been
+ corrected.
+
+ * The recently merged "rebase in C" has an escape hatch to use the
+ scripted version when necessary, but it hasn't been documented,
+ which has been corrected.
+
Performance, Internal Implementation, Development Support etc.
+ * Developer builds now use -Wunused-function compilation option.
+
+ * One of our CI tests to run with "unusual/experimental/random"
+ settings now also uses commit-graph and midx.
+
* When there are too many packfiles in a repository (which is not
recommended), looking up an object in these would require
consulting many pack .idx files; a new mechanism to have a single
used during tests are getting renamed for consistency.
(merge 4231d1ba99 bp/rename-test-env-var later to maint).
- * A new extension to the index file has been introduced, which allows
- the index file to be read in parallel for performance.
+ * A pair of new extensions to the index file have been introduced.
+ They allow the index file to be read in parallel for performance.
* The oidset API was built on top of the oidmap API which in turn is
on the hashmap API. Replace the implementation to build on top of
object exists, even for paths that are outside of the partial
checkout area. The code has been updated to avoid such a check.
+ * To help developers, an EditorConfig file that attempts to follow
+ the project convention has been added.
+ (merge b548d698a0 bc/editorconfig later to maint).
+
+ * The result of coverage test can be combined with "git blame" to
+ check the test coverage of code introduced recently with a new
+ 'coverage-diff' tool (in contrib/).
+ (merge 783faedd65 ds/coverage-diff later to maint).
+
+ * An experiment to fuzz test a few areas, hopefully we can gain more
+ coverage to various areas.
+
+ * More codepaths are moving away from hardcoded hash sizes.
+
+ * The way the Windows port figures out the current directory has been
+ improved.
+
+ * The way DLLs are loaded on the Windows port has been improved.
+
+ * Some tests have been reorganized and renamed; "ls t/" now gives a
+ better overview of what is tested for these scripts than before.
+
+ * "git rebase" and "git rebase -i" have been reimplemented in C.
+
+ * Windows port learned to use nano-second resolution file timestamps.
+
+ * The overly large Documentation/config.txt file have been split into
+ million little pieces. This potentially allows each individual piece
+ to be included into the manual page of the command it affects more easily.
+
+ * Replace three string-list instances used as look-up tables in "git
+ fetch" with hashmaps.
+
+ * Unify code to read the author-script used in "git am" and the
+ commands that use the sequencer machinery, e.g. "git rebase -i".
+
+ * In preparation to the day when we can deprecate and remove the
+ "rebase -p", make sure we can skip and later remove tests for
+ it.
+
+ * The history traversal used to implement the tag-following has been
+ optimized by introducing a new helper.
+
+ * The helper function to refresh the cached stat information in the
+ in-core index has learned to perform the lstat() part of the
+ operation in parallel on multi-core platforms.
+
+ * The code to traverse objects for reachability, used to decide what
+ objects are unreferenced and expendable, have been taught to also
+ consider per-worktree refs of other worktrees as starting points to
+ prevent data loss.
+
+ * "git add" needs to internally run "diff-files" equivalent, and the
+ codepath learned the same optimization as "diff-files" has to run
+ lstat(2) in parallel to find which paths have been updated in the
+ working tree.
+
+ * The procedure to install dependencies before testing at Travis CI
+ is getting revamped for both simplicity and flexibility, taking
+ advantage of the recent move to the vm-based environment.
+
+ * The support for format-patch (and send-email) by the command-line
+ completion script (in contrib/) has been simplified a bit.
+
+ * The revision walker machinery learned to take advantage of the
+ commit generation numbers stored in the commit-graph file.
+
+ * The codebase has been cleaned up to reduce "#ifndef NO_PTHREADS".
+
+ * The way -lcurl library gets linked has been simplified by taking
+ advantage of the fact that we can just ask curl-config command how.
+
+ * Various functions have been audited for "-Wunused-parameter" warnings
+ and bugs in them got fixed.
+
+ * A sanity check for start-up sequence has been added in the config
+ API codepath.
+
+ * The build procedure to link for fuzzing test has been made
+ customizable with a new Makefile variable.
+
+ * The way "git rebase" parses and forwards the command line options
+ meant for underlying "git am" has been revamped, which fixed for
+ options with parameters that were not passed correctly.
+
+ * Our testing framework uses a special i18n "poisoned localization"
+ feature to find messages that ought to stay constant but are
+ incorrectly marked to be translated. This feature has been made
+ into a runtime option (it used to be a compile-time option).
+
+ * "git push" used to check ambiguities between object-names and
+ refnames while processing the list of refs' old and new values,
+ which was unnecessary (as it knew that it is feeding raw object
+ names). This has been optimized out.
+
+ * The xcurl_off_t() helper function is used to cast size_t to
+ curl_off_t, but some compilers gave warnings against the code to
+ ensure the casting is done without wraparound, when size_t is
+ narrower than curl_off_t. This warning has been squelched.
+
+ * Code preparation to replace ulong vars with size_t vars where
+ appropriate continues.
+
+ * The "test installed Git" mode of our test suite has been updated to
+ work better.
+
+ * A coding convention around the Coccinelle semantic patches to have
+ two classes to ease code migration process has been proposed and
+ its support has been added to the Makefile.
+
+ * The "container" mode of TravisCI is going away. Our .travis.yml
+ file is getting prepared for the transition.
+ (merge 32ee384be8 ss/travis-ci-force-vm-mode later to maint).
+
+ * Our test scripts can now take the '-V' option as a synonym for the
+ '--verbose-log' option.
+ (merge a5f52c6dab sg/test-verbose-log later to maint).
+
Fixes since v2.19
-----------------
no blobs are needed.
(merge 4c7f9567ea jt/non-blob-lazy-fetch later to maint).
+ * The codepath to support the experimental split-index mode had
+ remaining "racily clean" issues fixed.
+ (merge 4c490f3d32 sg/split-index-racefix later to maint).
+
+ * "git log --graph" showing an octopus merge sometimes miscounted the
+ number of display columns it is consuming to show the merge and its
+ parent commits, which has been corrected.
+ (merge 04005834ed np/log-graph-octopus-fix later to maint).
+
+ * "git range-diff" did not work well when the compared ranges had
+ changes in submodules and the "--submodule=log" was used.
+
+ * The implementation of run_command() API on the UNIX platforms had a
+ bug that caused a command not on $PATH to be found in the current
+ directory.
+ (merge f67b980771 jk/run-command-notdot later to maint).
+
+ * A mutex used in "git pack-objects" were not correctly initialized
+ and this caused "git repack" to dump core on Windows.
+ (merge 34204c8166 js/pack-objects-mutex-init-fix later to maint).
+
+ * Under certain circumstances, "git diff D:/a/b/c D:/a/b/d" on
+ Windows would strip initial parts from the paths because they
+ were not recognized as absolute, which has been corrected.
+ (merge ffd04e92e2 js/diff-notice-has-drive-prefix later to maint).
+
+ * The receive.denyCurrentBranch=updateInstead codepath kicked in even
+ when the push should have been rejected due to other reasons, such
+ as it does not fast-forward or the update-hook rejects it, which
+ has been corrected.
+ (merge b072a25fad jc/receive-deny-current-branch-fix later to maint).
+
+ * The logic to determine the archive type "git archive" uses did not
+ correctly kick in for "git archive --remote", which has been
+ corrected.
+
+ * "git repack" in a shallow clone did not correctly update the
+ shallow points in the repository, leading to a repository that
+ does not pass fsck.
+ (merge 5dcfbf564c js/shallow-and-fetch-prune later to maint).
+
+ * Some codepaths failed to form a proper URL when .gitmodules record
+ the URL to a submodule repository as relative to the repository of
+ superproject, which has been corrected.
+ (merge e0a862fdaf sb/submodule-url-to-absolute later to maint).
+
+ * "git fetch" over protocol v2 into a shallow repository failed to
+ fetch full history behind a new tip of history that was diverged
+ before the cut-off point of the history that was previously fetched
+ shallowly.
+
+ * The command line completion machinery (in contrib/) has been
+ updated to allow the completion script to tweak the list of options
+ that are reported by the parse-options machinery correctly.
+ (merge 276b49ff34 nd/completion-negation later to maint).
+
+ * Operations on promisor objects make sense in the context of only a
+ small subset of the commands that internally use the revisions
+ machinery, but the "--exclude-promisor-objects" option were taken
+ and led to nonsense results by commands like "log", to which it
+ didn't make much sense. This has been corrected.
+ (merge 669b1d2aae md/exclude-promisor-objects-fix later to maint).
+
+ * A regression in Git 2.12 era made "git fsck" fall into an infinite
+ loop while processing truncated loose objects.
+ (merge 18ad13e5b2 jk/detect-truncated-zlib-input later to maint).
+
+ * "git ls-remote $there foo" was broken by recent update for the
+ protocol v2 and stopped showing refs that match 'foo' that are not
+ refs/{heads,tags}/foo, which has been fixed.
+ (merge 6a139cdd74 jk/proto-v2-ref-prefix-fix later to maint).
+
+ * Additional comment on a tricky piece of code to help developers.
+ (merge 0afbe3e806 jk/stream-pack-non-delta-clarification later to maint).
+
+ * A couple of tests used to leave the repository in a state that is
+ deliberately corrupt, which have been corrected.
+ (merge aa984dbe5e ab/pack-tests-cleanup later to maint).
+
+ * The submodule support has been updated to read from the blob at
+ HEAD:.gitmodules when the .gitmodules file is missing from the
+ working tree.
+ (merge 2b1257e463 ao/submodule-wo-gitmodules-checked-out later to maint).
+
+ * "git fetch" was a bit loose in parsing responses from the other side
+ when talking over the protocol v2.
+
+ * "git rev-parse --exclude=* --branches --branches" (i.e. first
+ saying "add only things that do not match '*' out of all branches"
+ and then adding all branches, without any exclusion this time)
+ worked as expected, but "--exclude=* --all --all" did not work the
+ same way, which has been fixed.
+ (merge 5221048092 ag/rev-parse-all-exclude-fix later to maint).
+
+ * "git send-email --transfer-encoding=..." in recent versions of Git
+ sometimes produced an empty "Content-Transfer-Encoding:" header,
+ which has been corrected.
+ (merge 3c88e46f1a al/send-email-auto-cte-fixup later to maint).
+
+ * The interface into "xdiff" library used to discover the offset and
+ size of a generated patch hunk by first formatting it into the
+ textual hunk header "@@ -n,m +k,l @@" and then parsing the numbers
+ out. A new interface has been introduced to allow callers a more
+ direct access to them.
+ (merge 5eade0746e jk/xdiff-interface later to maint).
+
+ * Pathspec matching against a tree object were buggy when negative
+ pathspec elements were involved, which has been fixed.
+ (merge b7845cebc0 nd/tree-walk-path-exclusion later to maint).
+
+ * "git merge" and "git pull" that merges into an unborn branch used
+ to completely ignore "--verify-signatures", which has been
+ corrected.
+ (merge 01a31f3bca jk/verify-sig-merge-into-void later to maint).
+
+ * "git rebase --autostash" did not correctly re-attach the HEAD at times.
+
+ * "rev-parse --exclude=<pattern> --branches=<pattern>" etc. did not
+ quite work, which has been corrected.
+ (merge 9ab9b5df0e ra/rev-parse-exclude-glob later to maint).
+
+ * When editing a patch in a "git add -i" session, a hunk could be
+ made to no-op. The "git apply" program used to reject a patch with
+ such a no-op hunk to catch user mistakes, but it is now updated to
+ explicitly allow a no-op hunk in an edited patch.
+ (merge 22cb3835b9 js/apply-recount-allow-noop later to maint).
+
+ * The URL to an MSDN page in a comment has been updated.
+ (merge 2ef2ae2917 js/mingw-msdn-url later to maint).
+
+ * "git ls-remote --sort=<thing>" can feed an object that is not yet
+ available into the comparison machinery and segfault, which has
+ been corrected to check such a request upfront and reject it.
+
+ * When "git bundle" aborts due to an empty commit ranges
+ (i.e. resulting in an empty pack), it left a file descriptor to an
+ lockfile open, which resulted in leftover lockfile on Windows where
+ you cannot remove a file with an open file descriptor. This has
+ been corrected.
+ (merge 2c8ee1f53c jk/close-duped-fd-before-unlock-for-bundle later to maint).
+
+ * "git format-patch --stat=<width>" can be used to specify the width
+ used by the diffstat (shown in the cover letter).
+ (merge 284aeb7e60 nd/format-patch-cover-letter-stat-width later to maint).
+
+ * The way .git/index and .git/sharedindex* files were initially
+ created gave these files different perm bits until they were
+ adjusted for shared repository settings. This was made consistent.
+ (merge c9d6c78870 cc/shared-index-permbits later to maint).
+
+ * "git rebase --stat" to transplant a piece of history onto a totally
+ unrelated history were not working before and silently showed wrong
+ result. With the recent reimplementation in C, it started to instead
+ die with an error message, as the original logic was not prepared
+ to cope with this case. This has now been fixed.
+
+ * The advice message to tell the user to migrate an existing graft
+ file to the replace system when a graft file was read was shown
+ even when "git replace --convert-graft-file" command, which is the
+ way the message suggests to use, was running, which made little
+ sense.
+ (merge 8821e90a09 ab/replace-graft-with-replace-advice later to maint).
+
+ * "git diff --raw" lost ellipses to adjust the output columns for
+ some time now, but the documentation still showed them.
+
* Code cleanup, docfix, build fix, etc.
(merge 96a7501aad ts/doc-build-manpage-xsl-quietly later to maint).
(merge b9b07efdb2 tg/conflict-marker-size later to maint).
(merge 6e8fc70fce rs/sequencer-oidset-insert-avoids-dups later to maint).
(merge ad0b8f9575 mw/doc-typofixes later to maint).
(merge d9f079ad1a jc/how-to-document-api later to maint).
+ (merge b1492bf315 ma/t7005-bash-workaround later to maint).
+ (merge ac1f98a0df du/rev-parse-is-plumbing later to maint).
+ (merge ca8ed443a5 mm/doc-no-dashed-git later to maint).
+ (merge ce366a8144 du/get-tar-commit-id-is-plumbing later to maint).
+ (merge 61018fe9e0 du/cherry-is-plumbing later to maint).
+ (merge c7e5fe79b9 sb/strbuf-h-update later to maint).
+ (merge 8d2008196b tq/branch-create-wo-branch-get later to maint).
+ (merge 2e3c894f4b tq/branch-style-fix later to maint).
+ (merge c5d844af9c sg/doc-show-branch-typofix later to maint).
+ (merge 081d91618b ah/doc-updates later to maint).
+ (merge b84c783882 jc/cocci-preincr later to maint).
+ (merge 5e495f8122 uk/merge-subtree-doc-update later to maint).
+ (merge aaaa881822 jk/uploadpack-packobjectshook-fix later to maint).
+ (merge 3063477445 tb/char-may-be-unsigned later to maint).
+ (merge 8c64bc9420 sg/test-rebase-editor-fix later to maint).
+ (merge 71571cd7d6 ma/sequencer-do-reset-saner-loop-termination later to maint).
+ (merge 9a4cb8781e cb/notes-freeing-always-null-fix later to maint).
+ (merge 3006f5ee16 ma/reset-doc-rendering-fix later to maint).
+ (merge 4c2eb06419 sg/daemon-test-signal-fix later to maint).
+ (merge d27525e519 ss/msvc-strcasecmp later to maint).