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The pseudo-merge commit lookup table stores each commit's position in the pack- or pseudo-pack order, and is used to perform a binary search in order to determine which pseudo-merge(s) a given commit belongs to. However, the table was previously sorted in lexical order (via `oid_array_sort()`), causing the binary search to fail. While this causes pseudo-merge bitmaps to be de-facto broken for fill-in traversal, there are a couple of important points to keep in mind: * Pseudo-merge application during the initial phases of a bitmap-based traversal are applied via `cascade_pseudo_merges_1()`. This function enumerates the known pseudo-merges and determines if its parents are a subset of the traversal roots. This is a different path than the fill-in traversal, where we are looking for any pseudo-merges which may be satisfied after visiting some commit along an object walk, which involves the aforementioned (broken) binary search. As a consequence, any pseudo-merges we apply at this stage are done so correctly. * While this bug makes applying pseudo-merges during fill-in traversal effectively broken, it does not produce wrong results. Instead of applying the *wrong* pseudo-merge, we will simply fail to find satisfied pseudo-merges, leaving the traversal to use the existing fill-in routines. Fix this by sorting the table by bit position before writing, matching the order that the reader's binary search expects. This does produce a change the on-disk format insofar as the actual code now complies with the documented format (for more details, refer to: Documentation/technical/bitmap-format.adoc). Given that this never worked in the first place, such a change should be OK to perform. If an out-of-tree implementation of pseudo-merges happened to generate bitmaps that comply with the documented format, they will continue to be read and interpreted as normal. 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.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).
To subscribe to the list, send an email to git+subscribe@vger.kernel.org (see https://subspace.kernel.org/subscribing.html for details). The mailing list archives are available at https://lore.kernel.org/git/, https://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