--- /dev/null
+Git Release Notes
+=================
+
+Backward Compatibility Notes
+----------------------------
+
+ * "git branch -l <foo>" used to be a way to ask a reflog to be
+ created while creating a new branch, but that is no longer the
+ case. It is a short-hand for "git branch --list <foo>" now.
+
+ * "git push" into refs/tags/* hierarchy is rejected without getting
+ forced, but "git fetch" (misguidedly) used the "fast forwarding"
+ rule used for the refs/heads/* hierarchy; this has been corrected,
+ which means some fetches of tags that did not fail with older
+ version of Git will fail without "--force" with this version.
+
+
+Updates since v2.19
+-------------------
+
+UI, Workflows & Features
+
+ * Running "git clone" against a project that contain two files with
+ pathnames that differ only in cases on a case insensitive
+ filesystem would result in one of the files lost because the
+ underlying filesystem is incapable of holding both at the same
+ time. An attempt is made to detect such a case and warn.
+
+ * "git checkout -b newbranch [HEAD]" should not have to do as much as
+ checking out a commit different from HEAD. An attempt is made to
+ optimize this special case.
+
+ * "git rev-list --stdin </dev/null" used to be an error; it now shows
+ no output without an error. "git rev-list --stdin --default HEAD"
+ still falls back to the given default when nothing is given on the
+ standard input.
+
+ * Lift code from GitHub to restrict delta computation so that an
+ object that exists in one fork is not made into a delta against
+ another object that does not appear in the same forked repository.
+
+ * "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
+ a comment).
+
+ * "git mailinfo" used in "git am" learned to make a best-effort
+ recovery of a patch corrupted by MUA that sends text/plain with
+ format=flawed option.
+ (merge 3aa4d81f88 rs/mailinfo-format-flowed later to maint).
+
+ * The rules used by "git push" and "git fetch" to determine if a ref
+ can or cannot be updated were inconsistent; specifically, fetching
+ to update existing tags were allowed even though tags are supposed
+ to be unmoving anchoring points. "git fetch" was taught to forbid
+ updates to existing tags without the "--force" option.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * 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
+ file that consolidates all of these .idx files is introduced.
+
+ * "git submodule update" is getting rewritten piece-by-piece into C.
+
+ * The code for computing history reachability has been shuffled,
+ obtained a bunch of new tests to cover them, and then being
+ improved.
+
+ * The unpack_trees() API used in checking out a branch and merging
+ walks one or more trees along with the index. When the cache-tree
+ in the index tells us that we are walking a tree whose flattened
+ contents is known (i.e. matches a span in the index), as linearly
+ scanning a span in the index is much more efficient than having to
+ open tree objects recursively and listing their entries, the walk
+ can be optimized, which has been done.
+
+ * When creating a thin pack, which allows objects to be made into a
+ delta against another object that is not in the resulting pack but
+ is known to be present on the receiving end, the code learned to
+ take advantage of the reachability bitmap; this allows the server
+ to send a delta against a base beyond the "boundary" commit.
+
+ * spatch transformation to replace boolean uses of !hashcmp() to
+ newly introduced oideq() is added, and applied, to regain
+ performance lost due to support of multiple hash algorithms.
+
+ * Fix a bug in which the same path could be registered under multiple
+ worktree entries if the path was missing (for instance, was removed
+ manually). Also, as a convenience, expand the number of cases in
+ which --force is applicable.
+
+
+Fixes since v2.19
+-----------------
+
+ * "git interpret-trailers" and its underlying machinery had a buggy
+ code that attempted to ignore patch text after commit log message,
+ which triggered in various codepaths that will always get the log
+ message alone and never get such an input.
+ (merge 66e83d9b41 jk/trailer-fixes later to maint).
+
+ * Malformed or crafted data in packstream can make our code attempt
+ to read or write past the allocated buffer and abort, instead of
+ reporting an error, which has been fixed.
+
+ * "git rebase -i" did not clear the state files correctly when a run
+ of "squash/fixup" is aborted and then the user manually amended the
+ commit instead, which has been corrected.
+ (merge 10d2f35436 js/rebase-i-autosquash-fix later to maint).
+
+ * When fsmonitor is in use, after operation on submodules updates
+ .gitmodules, we lost track of the fact that we did so and relied on
+ stale fsmonitor data.
+ (merge 43f1180814 bp/mv-submodules-with-fsmonitor later to maint).
+
+ * Fix for a long-standing bug that leaves the index file corrupt when
+ it shrinks during a partial commit.
+ (merge 6c003d6ffb jk/reopen-tempfile-truncate later to maint).
+
+ * Further fix for O_APPEND emulation on Windows
+ (merge eeaf7ddac7 js/mingw-o-append later to maint).
+
+ * A corner case bugfix in "git rerere" code.
+ (merge ad2bf0d9b4 en/rerere-multi-stage-1-fix later to maint).
+
+ * "git add ':(attr:foo)'" is not supported and is supposed to be
+ rejected while the command line arguments are parsed, but we fail
+ to reject such a command line upfront.
+ (merge 84d938b732 nd/attr-pathspec-fix later to maint).
+
+ * Recent update broke the reachability algorithm when refs (e.g.
+ tags) that point at objects that are not commit were involved,
+ which has been fixed.
+
+ * "git rebase" etc. in Git 2.19 fails to abort when given an empty
+ commit log message as result of editing, which has been corrected.
+ (merge a3ec9eaf38 en/sequencer-empty-edit-result-aborts later to maint).
+
+ * The code to backfill objects in lazily cloned repository did not
+ work correctly, which has been corrected.
+ (merge e68302011c jt/lazy-object-fetch-fix later to maint).
+
+ * Update error messages given by "git remote" and make them consistent.
+ (merge 5025425dff ms/remote-error-message-update later to maint).
+
+ * "git update-ref" learned to make both "--no-deref" and "--stdin"
+ work at the same time.
+ (merge d345e9fbe7 en/update-ref-no-deref-stdin later to maint).
+
+ * Recently added "range-diff" had a corner-case bug to cause it
+ segfault, which has been corrected.
+ (merge e467a90c7a tg/range-diff-corner-case-fix later to maint).
+
+ * 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 fa0aeea770 sg/doc-trace-appends later to maint).
+ (merge d64324cb60 tb/void-check-attr later to maint).
+ (merge c3b9bc94b9 en/double-semicolon-fix later to maint).
+ (merge 79336116f5 sg/t3701-tighten-trace later to maint).
+ (merge 801fa63a90 jk/dev-build-format-security later to maint).
+ (merge 0597dd62ba sb/string-list-remove-unused later to maint).
+ (merge db2d36fad8 bw/protocol-v2 later to maint).
+ (merge 456d7cd3a9 sg/split-index-test later to maint).
projects / thirdparty / git.git / blobdiff