23532be8e9
When passing a preferred pack to the MIDX write machinery, we ensure that the given preferred pack is non-empty since5d3cd09a80(midx: reject empty `--preferred-pack`'s, 2021-08-31). However packs are only loaded (via `write_midx_internal()`, though a subsequent patch will refactor this code out to its own function) when the `MIDX_WRITE_REV_INDEX` flag is set. So if a caller runs: $ git multi-pack-index write --preferred-pack=... with both (a) an existing MIDX, and (b) specifies a pack from that MIDX as the preferred one, without passing `--bitmap`, then the check added in5d3cd09a80will result in a segfault. Note that packs loaded from disk which don't appear in an existing MIDX do not trigger this issue, as those packs are loaded unconditionally. We conditionally load packs from a MIDX since we tolerate MIDXs whose packs do not resolve (i.e., via the MIDX write after removing unreferenced packs via 'git multi-pack-index expire'). In practice, this isn't possible to trigger when running `git multi-pack-index write` from `git repack`, as the latter always passes `--stdin-packs`, which prevents us from loading an existing MIDX, as it forces all packs to be read from disk. But a future commit in this series will change that behavior to unconditionally load an existing MIDX, even with `--stdin-packs`, making this behavior trigger-able from 'repack' much more easily. Prevent this from being an issue by removing the segfault altogether by calling `prepare_midx_pack()` on packs loaded from an existing MIDX when either the `MIDX_WRITE_REV_INDEX` flag is set *or* we specified a `--preferred-pack`. Signed-off-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 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):
- 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