mirror of
https://github.com/git/git.git
synced 2026-04-02 04:50:12 +02:00
90cb1c47c7
There is a subtle failure happening when computing corrected commit dates with --split enabled. It requires a base layer needing the generation_data_overflow chunk. Then, the next layer on top erroneously thinks it needs an overflow chunk due to a bug leading to recalculating all reachable generation numbers. The output of the failure is BUG: commit-graph.c:1912: expected to write 8 bytes to chunk 47444f56, but wrote 0 instead These "expected" 8 bytes are due to re-computing the corrected commit date for the lower layer but the new layer does not need any overflow. Add a test to t5318-commit-graph.sh that demonstrates this bug. However, it does not trigger consistently with the existing code. The generation number data is stored in a slab and accessed by commit_graph_data_at(). This data is initialized when parsing a commit, but is otherwise used assuming it has been populated. The loop in compute_generation_numbers() did not enforce that all reachable commits were parsed and had correct values. This could lead to some problems when writing a commit-graph with corrected commit dates based on a commit-graph without them. It has been difficult to identify the issue here because it was so hard to reproduce. It relies on this uninitialized data having a non-zero value, but also on specifically in a way that overwrites the existing data. This patch adds the extra parse to ensure the data is filled before we compute the generation number of a commit. This triggers the new test to fail because the generation number overflow count does not match between this computation and the write for that chunk. The actual fix will follow as the next few changes. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git - fast, scalable, distributed revision control system
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.txt to get started, then see
Documentation/giteveryday.txt for a useful minimum set of commands, and
Documentation/git-<commandname>.txt 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.txt
(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). To subscribe to the list, send an email with just "subscribe git" in the body to majordomo@vger.kernel.org. The mailing list archives are available at https://lore.kernel.org/git/, http://marc.info/?l=git and other archival sites.
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):
- random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of "get" may or may not be relevant.
- stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang.
- "global information tracker": you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room.
- "goddamn idiotic truckload of sh*t": when it breaks