builtin/stash: merge index in-core "git stash apply --index" does a 2-step dance to report index conflicts before carrying out the main unstash: first, attempt to merge the index (and remember the name of the resulting tree). If that succeeds, reset the index and carry on unstashing the working tree, then use the remembered index tree to unstash the index. The "merge the index" step is performed on the actual index by a combination of git-diff-tree(1) and git-apply(1), which incurs an extra cost to git-reset(1) to cleanup. This also introduces an autostash bug when stash.index is true: "git reset" eventually wants to remove_merge_branch_state(), which calls save_autostash() due to a03b55530a (merge: teach --autostash option, 2020-04-07). This can happen from a "git merge --autostash", which itself calls save_autostash(). Operating on the file-system in this way is not re-entrant, so we end up trying to lock a now-deleted MERGE_AUTOSTASH ref [1]. This bug has lurked for a while, but it would have been impossible to trigger without the availability of stash.index to force the autostash apply into index mode. [1]: https://lore.kernel.org/git/CALO-guvbk2TcrVwzdNQ3yRpzHr0HHZ3h1wite0Xp0sUyAT4otA@mail.gmail.com/ Fortunately, we can achieve 2 goals at once: avoid round-tripping to the file-system (and invoking expensive subprocesses) by performing the merge in-core. If there are conflicts, we discard the resulting tree, so we don't see the usual branch and ancestor labels, but the merge subroutines insist on their presence, so use something simple. We need to take care to get the order of trees right when merging. Add a test that covers this case. We *could* swap just the git-reset(1) subprocess with our internal reset_tree() and refresh_index(), which would fix the bug. We'd much prefer to clean up these vestiges of the shell-based git-stash, though. Reported-by: Eli Barzilay <eli@barzilay.org> Helped-by: Phillip Wood <phillip.wood@dunelm.org.uk> Helped-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: D. Ben Knoble <ben.knoble@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.
Git is an Open Source project covered by the GNU General Public License version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.
Please read the file INSTALL for installation instructions.
Many Git online resources are accessible from https://git-scm.com/ including full documentation and Git related tools.
See Documentation/gittutorial.adoc to get started, then see Documentation/giteveryday.adoc for a useful minimum set of commands, and Documentation/git-<commandname>.adoc for documentation of each command. If git has been correctly installed, then the tutorial can also be read with man gittutorial or git help tutorial, and the documentation of each command with man git-<commandname> or git help <commandname>.
CVS users may also want to read Documentation/gitcvs-migration.adoc (man gitcvs-migration or git help cvs-migration if git is installed).
The user discussion and development of Git take place on the Git mailing list -- everyone is welcome to post bug reports, feature requests, comments and patches to git@vger.kernel.org (read Documentation/SubmittingPatches for instructions on patch submission and Documentation/CodingGuidelines).
Those wishing to help with error message, usage and informational message string translations (localization l10) should see po/README.md (a po file is a Portable Object file that holds the translations).
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Issues which are security relevant should be disclosed privately to the Git Security mailing list git-security@googlegroups.com.
The maintainer frequently sends the “What's cooking” reports that list the current status of various development topics to the mailing list. The discussion following them give a good reference for project status, development direction and remaining tasks.
The name “git” was given by Linus Torvalds when he wrote the very first version. He described the tool as “the stupid content tracker” and the name as (depending on your mood):