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The --no-index option of git-diff enables using the diff machinery from git while operating outside of a repository. This mode of git diff is able to compare directories and produce a diff of their contents. When operating git diff in a repository, git has the notion of "pathspecs" which can specify which files to compare. In particular, when using git to diff two trees, you might invoke: $ git diff-tree -r <treeish1> <treeish2>. where the treeish could point to a subdirectory of the repository. When invoked this way, users can limit the selected paths of the tree by using a pathspec. Either by providing some list of paths to accept, or by removing paths via a negative refspec. The git diff --no-index mode does not support pathspecs, and cannot limit the diff output in this way. Other diff programs such as GNU difftools have options for excluding paths based on a pattern match. However, using git diff as a diff replacement has several advantages over many popular diff tools, including coloring moved lines, rename detections, and similar. Teach git diff --no-index how to handle pathspecs to limit the comparisons. This will only be supported if both provided paths are directories. For comparisons where one path isn't a directory, the --no-index mode already has some DWIM shortcuts implemented in the fixup_paths() function. Modify the fixup_paths function to return 1 if both paths are directories. If this is the case, interpret any extra arguments to git diff as pathspecs via parse_pathspec. Use parse_pathspec to load the remaining arguments (if any) to git diff --no-index as pathspec items. Disable PATHSPEC_ATTR support since we do not have a repository to do attribute lookup. Disable PATHSPEC_FROMTOP since we do not have a repository root. All pathspecs are treated as rooted at the provided comparison paths. After loading the pathspec data, calculate skip offsets for skipping past the root portion of the paths. This is required to ensure that pathspecs start matching from the provided path, rather than matching from the absolute path. We could instead pass the paths as prefix values to parse_pathspec. This is slightly problematic because the paths come from the command line and don't necessarily have the proper trailing slash. Additionally, that would require parsing pathspecs multiple times. Pass the pathspec object and the skip offsets into queue_diff, which in-turn must pass them along to read_directory_contents. Modify read_directory_contents to check against the pathspecs when scanning the directory. Use the skip offset to skip past the initial root of the path, and only match against portions that are below the intended directory structure being compared. The search algorithm for finding paths is recursive with read_dir. To make pathspec matching work properly, we must set both DO_MATCH_DIRECTORY and DO_MATCH_LEADING_PATHSPEC. Without DO_MATCH_DIRECTORY, paths like "a/b/c/d" will not match against pathspecs like "a/b/c". This is usually achieved by setting the is_dir parameter of match_pathspec. Without DO_MATCH_LEADING_PATHSPEC, paths like "a/b/c" would not match against pathspecs like "a/b/c/d". This is crucial because we recursively iterate down the directories. We could simply avoid checking pathspecs at subdirectories, but this would force recursion down directories which would simply be skipped. If we always passed DO_MATCH_LEADING_PATHSPEC, then we will incorrectly match in certain cases such as matching 'a/c' against ':(glob)**/d'. The match logic will see that a matches the leading part of the **/ and accept this even tho c doesn't match. To avoid this, use the match_leading_pathspec() variant recently introduced. This sets both flags when is_dir is set, but leaves them both cleared when is_dir is 0. Add test cases and documentation covering the new functionality. Note for the documentation I opted not to move the placement of '--' which is sometimes used to disambiguate arguments. The diff --no-index mode requires exactly 2 arguments determining what to compare. Any additional arguments are interpreted as pathspecs and must come afterwards. Use of '--' would not actually disambiguate anything, since there will never be ambiguity over which arguments represent paths or pathspecs. Signed-off-by: Jacob Keller <jacob.keller@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