Johannes Schindelin
c3a6be2333
Incremental MIDX support made object-offset pack IDs local to each layer and then converted them to chain-global IDs by adding `num_packs_in_base`. The conversion was introduced by19419821ba(midx: teach `nth_midxed_pack_int_id()` about incremental MIDXs, 2024-08-06). Chain-aware pack preparation followed in1820bd878c(midx: teach `prepare_midx_pack()` about incremental MIDXs, 2024-08-06), but the final `midx_fill_entry()` lookup remained tied to the original layer. Only with8f909ff4e9(packfile: recover when a multi-pack-index names a removed pack, 2026-08-29) did Coverity point out this issue: a local ID such as `UINT32_MAX` could wrap when the base-pack count was added, producing a plausible but incorrect global ID. After `prepare_midx_pack()` resolved the chain, `midx_fill_entry()` could then underflow or address the wrong layer while indexing the current layer's pack array, causing an invalid memory access and crashing Git. Validate each local pack ID against its layer's pack count before adding the base count, and obtain the final pack through `nth_midxed_pack()`, which resolves the correct MIDX layer. This prevents an invalid local ID from wrapping during conversion and ensures that the lookup uses the layer identified by the resolved chain-global ID. Assisted-by: GPT-5.6 Luna Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> 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.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).
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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