read-cache: use freshen_shared_index() in read_index_from()

[alt-git.git] / Documentation / RelNotes / 2.12.0.txt

Git 2.12 Release Notes
======================

Backward compatibility notes.

 * Use of an empty string 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 not scheduled to happen in the upcoming release (yet).

 * The historical argument order "git merge <msg> HEAD <commit>..."
   has been deprecated for quite some time, and will be removed in the
   upcoming release.


Updates since v2.11
-------------------

UI, Workflows & Features

 * Various updates to "git p4".

 * "git p4" didn't interact with the internal of .git directory
   correctly in the modern "git-worktree"-enabled world.

 * "git branch --list" and friends learned "--ignore-case" option to
   optionally sort branches and tags case insensitively.

 * In addition to %(subject), %(body), "log --pretty=format:..."
   learned a new placeholder %(trailers).

 * "git rebase" learned "--quit" option, which allows a user to
   remove the metadata left by an earlier "git rebase" that was
   manually aborted without using "git rebase --abort".

 * "git clone --reference $there --recurse-submodules $super" has been
   taught to guess repositories usable as references for submodules of
   $super that are embedded in $there while making a clone of the
   superproject borrow objects from $there; extend the mechanism to
   also allow submodules of these submodules to borrow repositories
   embedded in these clones of the submodules embedded in the clone of
   the superproject.


Performance, Internal Implementation, Development Support etc.

 * Commands that operate on a log message and add lines to the trailer
   blocks, such as "format-patch -s", "cherry-pick (-x|-s)", and
   "commit -s", have been taught to use the logic of and share the
   code with "git interpret-trailer".

 * The default Travis-CI configuration specifies newer P4 and GitLFS.
   (merge 5f703e8f02 ls/travis-update-p4-and-lfs later to maint).

 * The "fast hash" that had disastrous performance issues in some
   corner cases has been retired from the internal diff.

 * The character width table has been updated to match Unicode 9.0
   (merge 9e6e9aefdf bb/unicode-9.0 later to maint).

 * Update the procedure to generate "tags" for developer support.
   (merge 046e4c1c09 jk/make-tags-find-sources-tweak later to maint).



Also contains various documentation updates and code clean-ups.

Fixes since v2.10
-----------------

Unless otherwise noted, all the fixes since v2.9 in the maintenance
track are contained in this release (see the maintenance releases'
notes for details).

 * We often decide if a session is interactive by checking if the
   standard I/O streams are connected to a TTY, but isatty() that
   comes with Windows incorrectly returned true if it is used on NUL
   (i.e. an equivalent to /dev/null).  This has been fixed.
   (merge cbb3f3c9b1 js/mingw-isatty later to maint).

 * "git svn" did not work well with path components that are "0", and
   some configuration variable it uses were not documented.
   (merge ea9a93dcc2 ew/svn-fixes later to maint).

 * "git rev-parse --symbolic" failed with a more recent notation like
   "HEAD^-1" and "HEAD^!".
   (merge a2e7b04c44 jk/rev-parse-symbolic-parents-fix later to maint).

 * An empty directory in a working tree that can simply be nuked used
   to interfere while merging or cherry-picking a change to create a
   submodule directory there, which has been fixed..
   (merge 5423d2e700 dt/empty-submodule-in-merge later to maint).

 * The code in "git push" to compute if any commit being pushed in the
   superproject binds a commit in a submodule that hasn't been pushed
   out was overly inefficient, making it unusable even for a small
   project that does not have any submodule but have a reasonable
   number of refs.
   (merge 250ab24ab3 hv/submodule-not-yet-pushed-fix later to maint).

 * "git push --dry-run --recurse-submodule=on-demand" wasn't
   "--dry-run" in the submodules.
   (merge 0301c821c5 bw/push-dry-run later to maint).

 * The output from "git worktree list" was made in readdir() order,
   and was unstable.
   (merge 4df1d4d466 nd/worktree-list-fixup later to maint).

 * mergetool.<tool>.trustExitCode configuration variable did not apply
   to built-in tools, but now it does.
   (merge 2967284456 da/mergetool-trust-exit-code later to maint).

 * "git p4" LFS support was broken when LFS stores an empty blob.
   (merge d5eb3cf5e7 ls/p4-empty-file-on-lfs later to maint).

 * A corner case in merge-recursive regression that crept in
   during 2.10 development cycle has been fixed.
   (merge 1c25d2d8ed jc/renormalize-merge-kill-safer-crlf later to maint).

 * Transport with dumb http can be fooled into following foreign URLs
   that the end user does not intend to, especially with the server
   side redirects and http-alternates mechanism, which can lead to
   security issues.  Tighten the redirection and make it more obvious
   to the end user when it happens.
   (merge cb4d2d35c4 jk/http-walker-limit-redirect-2.9 later to maint).

 * Update the error messages from the dumb-http client when it fails
   to obtain loose objects; we used to give sensible error message
   only upon 404 but we now forbid unexpected redirects that needs to
   be reported with something sensible.
   (merge 3680f16f9d jk/http-walker-limit-redirect later to maint).

 * When diff.renames configuration is on (and with Git 2.9 and later,
   it is enabled by default, which made it worse), "git stash"
   misbehaved if a file is removed and another file with a very
   similar content is added.
   (merge 9d4e28ead5 jk/stash-disable-renames-internally later to maint).

 * "git diff --no-index" did not take "--no-abbrev" option.
   (merge 43d1948b7b jb/diff-no-index-no-abbrev later to maint).

 * "git difftool --dir-diff" had a minor regression when started from
   a subdirectory, which has been fixed.
   (merge 853e10c197 da/difftool-dir-diff-fix later to maint).

 * "git commit --allow-empty --only" (no pathspec) with dirty index
   ought to be an acceptable way to create a new commit that does not
   change any paths, but it was forbidden, perhaps because nobody
   needed it so far.
   (merge beb635ca9c ak/commit-only-allow-empty later to maint).

 * Git 2.11 had a minor regression in "merge --ff-only" that competed
   with another process that simultanously attempted to update the
   index. We used to explain what went wrong with an error message,
   but the new code silently failed.  The error message has been
   resurrected.

 * A pathname that begins with "//" or "\\" on Windows is special but
   path normalization logic was unaware of it.
   (merge 7814fbe3f1 js/normalize-path-copy-ceil later to maint).

 * "git pull --rebase", when there is no new commits on our side since
   we forked from the upstream, should be able to fast-forward without
   invoking "git rebase", but it didn't.
   (merge 33b842a1e9 jc/pull-rebase-ff later to maint).

 * The way to specify hotkeys to "xxdiff" that is used by "git
   mergetool" has been modernized to match recent versions of xxdiff.
   (merge 6cf5f6cef7 da/mergetool-xxdiff-hotkey later to maint).

 * Unlike "git am --abort", "git cherry-pick --abort" moved HEAD back
   to where cherry-pick started while picking multiple changes, when
   the cherry-pick stopped to ask for help from the user, and the user
   did "git reset --hard" to a different commit in order to re-attempt
   the operation.
   (merge ce73bb22d8 sb/sequencer-abort-safety later to maint).

 * Code cleanup in shallow boundary computation.
   (merge 649b0c316a nd/shallow-fixup later to maint).

 * A recent update to receive-pack to make it easier to drop garbage
   objects made it clear that GIT_ALTERNATE_OBJECT_DIRECTORIES cannot
   have a pathname with a colon in it (no surprise!), and this in turn
   made it impossible to push into a repository at such a path.  This
   has been fixed by introducing a quoting mechanism used when
   appending such a path to the colon-separated list.
   (merge 5e74824fac jk/quote-env-path-list-component later to maint).

 * The function usage_msg_opt() has been updated to say "fatal:"
   before the custom message programs give, when they want to die
   with a message about wrong command line options followed by the
   standard usage string.
   (merge 87433261a4 jk/parseopt-usage-msg-opt later to maint).

 * "git index-pack --stdin" needs an access to an existing repository,
   but "git index-pack file.pack" to generate an .idx file that
   corresponds to a packfile does not.
   (merge 29401e1575 jk/index-pack-wo-repo-from-stdin later to maint).

 * Fix for NDEBUG builds.
   (merge 08414938a2 jt/mailinfo-fold-in-body-headers later to maint).

 * Other minor doc, test and build updates and code cleanups.
   (merge fa6ca11105 nd/qsort-in-merge-recursive later to maint).
   (merge fa3142c919 ak/lazy-prereq-mktemp later to maint).
   (merge 9c48b4fb23 ls/t0021-fixup later to maint).
   (merge 584f99c87b sb/unpack-trees-grammofix later to maint).
   (merge 54471fdcc3 jk/readme-gmane-is-no-more later to maint).
   (merge 9e189f1a5c sb/t3600-cleanup later to maint).
   (merge e2c20be57c lr/doc-fix-cet later to maint).
   (merge 47437fd3bd kh/tutorial-grammofix later to maint).