d09a6a2ef3
Add support for external diff processes that communicate via the
long-running process protocol (pkt-line over stdin/stdout).
A diff process is configured per userdiff driver:
[diff "cdiff"]
process = /path/to/diff-tool
The tool provides custom line-matching: it receives file pairs
and returns hunks that reference line numbers in the content.
When textconv is also configured, the tool receives the
textconv-transformed content. The tool controls which lines
are marked as changed while the display shows the file content.
Patch output features (word diff, function context, color) work
normally; --stat uses its own diff codepath and never consults
the diff process.
The handshake negotiates version=1 and capability=hunks. Per-file
requests send command=hunks, pathname, and both file contents as
packetized data. The tool responds with hunk lines and a status
packet (success, error, or abort). On error, Git warns and falls
back to the builtin diff algorithm for that file. On abort, Git
silently falls back for the current file and stops sending further
requests to the tool for the remainder of the session.
When the tool returns no hunks followed by status=success, Git
treats the file as having no changes and produces no diff output.
This also means --exit-code reports no changes for that file.
The subprocess is stored on the userdiff_driver struct and
launched on first use. If the process fails to start, the
handshake fails, or a communication error occurs mid-stream,
the failure is cached on the driver to avoid retrying and
re-warning on every subsequent file.
diff_process_fill_hunks() is the sole public entry point. It
handles driver lookup, flag checks, subprocess management, and
error reporting, returning an enum that lets callers distinguish
"hunks populated" from "files equivalent" from "not applicable"
from "tool failure."
Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Michael Montalbo <mmontalbo@gmail.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