-Checklist (and a short version for the impatient):
-
- Commits:
-
- - make commits of logical units
- - check for unnecessary whitespace with "git diff --check"
- before committing
- - do not check in commented out code or unneeded files
- - the first line of the commit message should be a short
- description (50 characters is the soft limit, see DISCUSSION
- in git-commit(1)), and should skip the full stop
- - it is also conventional in most cases to prefix the
- first line with "area: " where the area is a filename
- or identifier for the general area of the code being
- modified, e.g.
- . archive: ustar header checksum is computed unsigned
- . git-cherry-pick.txt: clarify the use of revision range notation
- (if in doubt which identifier to use, run "git log --no-merges"
- on the files you are modifying to see the current conventions)
- - the body should provide a meaningful commit message, which:
- . explains the problem the change tries to solve, iow, what
- is wrong with the current code without the change.
- . justifies the way the change solves the problem, iow, why
- the result with the change is better.
- . alternate solutions considered but discarded, if any.
- - describe changes in imperative mood, e.g. "make xyzzy do frotz"
- instead of "[This patch] makes xyzzy do frotz" or "[I] changed
- xyzzy to do frotz", as if you are giving orders to the codebase
- to change its behaviour.
- - try to make sure your explanation can be understood without
- external resources. Instead of giving a URL to a mailing list
- archive, summarize the relevant points of the discussion.
- - add a "Signed-off-by: Your Name <you@example.com>" line to the
- commit message (or just use the option "-s" when committing)
- to confirm that you agree to the Developer's Certificate of Origin
- - make sure that you have tests for the bug you are fixing
- - make sure that the test suite passes after your commit
-
- Patch:
-
- - use "git format-patch -M" to create the patch
- - do not PGP sign your patch
- - do not attach your patch, but read in the mail
- body, unless you cannot teach your mailer to
- leave the formatting of the patch alone.
- - be careful doing cut & paste into your mailer, not to
- corrupt whitespaces.
- - provide additional information (which is unsuitable for
- the commit message) between the "---" and the diffstat
- - if you change, add, or remove a command line option or
- make some other user interface change, the associated
- documentation should be updated as well.
- - if your name is not writable in ASCII, make sure that
- you send off a message in the correct encoding.
- - send the patch to the list (git@vger.kernel.org) and the
- maintainer (gitster@pobox.com) if (and only if) the patch
- is ready for inclusion. If you use git-send-email(1),
- please test it first by sending email to yourself.
- - see below for instructions specific to your mailer
-
-Long version:
-
-I started reading over the SubmittingPatches document for Linux
-kernel, primarily because I wanted to have a document similar to
-it for the core GIT to make sure people understand what they are
-doing when they write "Signed-off-by" line.
-
-But the patch submission requirements are a lot more relaxed
-here on the technical/contents front, because the core GIT is
-thousand times smaller ;-). So here is only the relevant bits.
+Here are some guidelines for people who want to contribute their code
+to this software.
(0) Decide what to base your work on.
wait until some of the dependent topics graduate to 'master', and
rebase your work.
+ - Some parts of the system have dedicated maintainers with their own
+ repositories (see the section "Subsystems" below). Changes to
+ these parts should be based on their trees.
+
To find the tip of a topic branch, run "git log --first-parent
master..pu" and look for the merge commit. The second parent of this
commit is the tip of the topic branch.
differs substantially from the prior version, are all good things
to have.
-Oh, another thing. I am picky about whitespaces. Make sure your
+Make sure that you have tests for the bug you are fixing. See
+t/README for guidance.
+
+When adding a new feature, make sure that you have new tests to show
+the feature triggers the new behavior when it should, and to show the
+feature does not trigger when it shouldn't. After any code change, make
+sure that the entire test suite passes.
+
+If you have an account at GitHub (and you can get one for free to work
+on open source projects), you can use their Travis CI integration to
+test your changes on Linux, Mac (and hopefully soon Windows). See
+GitHub-Travis CI hints section for details.
+
+Do not forget to update the documentation to describe the updated
+behavior and make sure that the resulting documentation set formats
+well. It is currently a liberal mixture of US and UK English norms for
+spelling and grammar, which is somewhat unfortunate. A huge patch that
+touches the files all over the place only to correct the inconsistency
+is not welcome, though. Potential clashes with other changes that can
+result from such a patch are not worth it. We prefer to gradually
+reconcile the inconsistencies in favor of US English, with small and
+easily digestible patches, as a side effect of doing some other real
+work in the vicinity (e.g. rewriting a paragraph for clarity, while
+turning en_UK spelling to en_US). Obvious typographical fixes are much
+more welcomed ("teh -> "the"), preferably submitted as independent
+patches separate from other documentation changes.
+
+Oh, another thing. We are picky about whitespaces. Make sure your
changes do not trigger errors with the sample pre-commit hook shipped
in templates/hooks--pre-commit. To help ensure this does not happen,
run git diff --check on your changes before you commit.
-(2) Generate your patch using git tools out of your commits.
+(2) Describe your changes well.
+
+The first line of the commit message should be a short description (50
+characters is the soft limit, see DISCUSSION in git-commit(1)), and
+should skip the full stop. It is also conventional in most cases to
+prefix the first line with "area: " where the area is a filename or
+identifier for the general area of the code being modified, e.g.
+
+ . doc: clarify distinction between sign-off and pgp-signing
+ . githooks.txt: improve the intro section
+
+If in doubt which identifier to use, run "git log --no-merges" on the
+files you are modifying to see the current conventions.
+
+It's customary to start the remainder of the first line after "area: "
+with a lower-case letter. E.g. "doc: clarify...", not "doc:
+Clarify...", or "githooks.txt: improve...", not "githooks.txt:
+Improve...".
+
+The body should provide a meaningful commit message, which:
+
+ . explains the problem the change tries to solve, iow, what is wrong
+ with the current code without the change.
+
+ . justifies the way the change solves the problem, iow, why the
+ result with the change is better.
+
+ . alternate solutions considered but discarded, if any.
+
+Describe your changes in imperative mood, e.g. "make xyzzy do frotz"
+instead of "[This patch] makes xyzzy do frotz" or "[I] changed xyzzy
+to do frotz", as if you are giving orders to the codebase to change
+its behaviour. Try to make sure your explanation can be understood
+without external resources. Instead of giving a URL to a mailing list
+archive, summarize the relevant points of the discussion.
+
+If you want to reference a previous commit in the history of a stable
+branch, use the format "abbreviated sha1 (subject, date)",
+with the subject enclosed in a pair of double-quotes, like this:
+
+ Commit f86a374 ("pack-bitmap.c: fix a memleak", 2015-03-30)
+ noticed that ...
-git based diff tools generate unidiff which is the preferred format.
+The "Copy commit summary" command of gitk can be used to obtain this
+format, or this invocation of "git show":
+
+ git show -s --date=short --pretty='format:%h ("%s", %ad)' <commit>
+
+(3) Generate your patch using Git tools out of your commits.
+
+Git based diff tools generate unidiff which is the preferred format.
You do not have to be afraid to use -M option to "git diff" or
"git format-patch", if your patch involves file renames. The
receiving end can handle them just fine.
-Please make sure your patch does not include any extra files
-which do not belong in a patch submission. Make sure to review
+Please make sure your patch does not add commented out debugging code,
+or include any extra files which do not relate to what your patch
+is trying to achieve. Make sure to review
your patch after generating it, to ensure accuracy. Before
sending out, please make sure it cleanly applies to the "master"
branch head. If you are preparing a work based on "next" branch,
that is fine, but please mark it as such.
-(3) Sending your patches.
+(4) Sending your patches.
-People on the git mailing list need to be able to read and
+Learn to use format-patch and send-email if possible. These commands
+are optimized for the workflow of sending patches, avoiding many ways
+your existing e-mail client that is optimized for "multipart/*" mime
+type e-mails to corrupt and render your patches unusable.
+
+People on the Git mailing list need to be able to read and
comment on the changes you are submitting. It is important for
a developer to be able to "quote" your changes, using standard
e-mail tools, so that they may comment on specific portions of
-your code. For this reason, all patches should be submitted
-"inline". WARNING: Be wary of your MUAs word-wrap
+your code. For this reason, each patch should be submitted
+"inline" in a separate message.
+
+Multiple related patches should be grouped into their own e-mail
+thread to help readers find all parts of the series. To that end,
+send them as replies to either an additional "cover letter" message
+(see below), the first patch, or the respective preceding patch.
+
+If your log message (including your name on the
+Signed-off-by line) is not writable in ASCII, make sure that
+you send off a message in the correct encoding.
+
+WARNING: Be wary of your MUAs word-wrap
corrupting your patch. Do not cut-n-paste your patch; you can
lose tabs that way if you are not careful.
You often want to add additional explanation about the patch,
other than the commit message itself. Place such "cover letter"
-material between the three dash lines and the diffstat. Git-notes
-can also be inserted using the `--notes` option.
+material between the three-dash line and the diffstat. For
+patches requiring multiple iterations of review and discussion,
+an explanation of changes between each iteration can be kept in
+Git-notes and inserted automatically following the three-dash
+line via `git format-patch --notes`.
Do not attach the patch as a MIME attachment, compressed or not.
Do not let your e-mail client send quoted-printable. Do not let
Exception: If your mailer is mangling patches then someone may ask
you to re-send them using MIME, that is OK.
-Do not PGP sign your patch, at least for now. Most likely, your
-maintainer or other people on the list would not have your PGP
-key and would not bother obtaining it anyway. Your patch is not
-judged by who you are; a good patch from an unknown origin has a
-far better chance of being accepted than a patch from a known,
-respected origin that is done poorly or does incorrect things.
+Do not PGP sign your patch. Most likely, your maintainer or other people on the
+list would not have your PGP key and would not bother obtaining it anyway.
+Your patch is not judged by who you are; a good patch from an unknown origin
+has a far better chance of being accepted than a patch from a known, respected
+origin that is done poorly or does incorrect things.
If you really really really really want to do a PGP signed
patch, format it as "multipart/signed", not a text/plain message
that starts with '-----BEGIN PGP SIGNED MESSAGE-----'. That is
not a text/plain, it's something else.
-Unless your patch is a very trivial and an obviously correct one,
-first send it with "To:" set to the mailing list, with "cc:" listing
+Send your patch with "To:" set to the mailing list, with "cc:" listing
people who are involved in the area you are touching (the output from
"git blame $path" and "git shortlog --no-merges $path" would help to
-identify them), to solicit comments and reviews. After the list
-reached a consensus that it is a good idea to apply the patch, re-send
-it with "To:" set to the maintainer and optionally "cc:" the list for
-inclusion. Do not forget to add trailers such as "Acked-by:",
-"Reviewed-by:" and "Tested-by:" after your "Signed-off-by:" line as
-necessary.
+identify them), to solicit comments and reviews.
+
+After the list reached a consensus that it is a good idea to apply the
+patch, re-send it with "To:" set to the maintainer [*1*] and "cc:" the
+list [*2*] for inclusion.
+
+Do not forget to add trailers such as "Acked-by:", "Reviewed-by:" and
+"Tested-by:" lines as necessary to credit people who helped your
+patch.
+ [Addresses]
+ *1* The current maintainer: gitster@pobox.com
+ *2* The mailing list: git@vger.kernel.org
-(4) Sign your work
+
+(5) Certify your work by adding your "Signed-off-by: " line
To improve tracking of who did what, we've borrowed the
"sign-off" procedure from the Linux kernel project on patches
-that are being emailed around. Although core GIT is a lot
+that are being emailed around. Although core Git is a lot
smaller project it is a good discipline to follow it.
The sign-off is a simple line at the end of the explanation for
person who certified (a), (b) or (c) and I have not modified
it.
- (d) I understand and agree that this project and the contribution
- are public and that a record of the contribution (including all
- personal information I submit with it, including my sign-off) is
- maintained indefinitely and may be redistributed consistent with
- this project or the open source license(s) involved.
+ (d) I understand and agree that this project and the contribution
+ are public and that a record of the contribution (including all
+ personal information I submit with it, including my sign-off) is
+ maintained indefinitely and may be redistributed consistent with
+ this project or the open source license(s) involved.
then you just add a line saying
- Signed-off-by: Random J Developer <random@developer.example.org>
+ Signed-off-by: Random J Developer <random@developer.example.org>
-This line can be automatically added by git if you run the git-commit
+This line can be automatically added by Git if you run the git-commit
command with the -s option.
Notice that you can place your own Signed-off-by: line when
You can also create your own tag or use one that's in common usage
such as "Thanks-to:", "Based-on-patch-by:", or "Mentored-by:".
+------------------------------------------------
+Subsystems with dedicated maintainers
+
+Some parts of the system have dedicated maintainers with their own
+repositories.
+
+ - git-gui/ comes from git-gui project, maintained by Pat Thoyts:
+
+ git://repo.or.cz/git-gui.git
+
+ - gitk-git/ comes from Paul Mackerras's gitk project:
+
+ git://ozlabs.org/~paulus/gitk
+
+ - po/ comes from the localization coordinator, Jiang Xin:
+
+ https://github.com/git-l10n/git-po/
+
+Patches to these parts should be based on their trees.
+
------------------------------------------------
An ideal patch flow
spend their time to improve your patch. Go back to step (2).
(4) The list forms consensus that the last round of your patch is
- good. Send it to the list and cc the maintainer.
+ good. Send it to the maintainer and cc the list.
(5) A topic branch is created with the patch and is merged to 'next',
and cooked further and eventually graduates to 'master'.
tell you if your patch is merged in pu if you rebase on top of
master).
-* Read the git mailing list, the maintainer regularly posts messages
+* Read the Git mailing list, the maintainer regularly posts messages
entitled "What's cooking in git.git" and "What's in git.git" giving
the status of various proposed changes.
+--------------------------------------------------
+GitHub-Travis CI hints
+
+With an account at GitHub (you can get one for free to work on open
+source projects), you can use Travis CI to test your changes on Linux,
+Mac (and hopefully soon Windows). You can find a successful example
+test build here: https://travis-ci.org/git/git/builds/120473209
+
+Follow these steps for the initial setup:
+
+ (1) Fork https://github.com/git/git to your GitHub account.
+ You can find detailed instructions how to fork here:
+ https://help.github.com/articles/fork-a-repo/
+
+ (2) Open the Travis CI website: https://travis-ci.org
+
+ (3) Press the "Sign in with GitHub" button.
+
+ (4) Grant Travis CI permissions to access your GitHub account.
+ You can find more information about the required permissions here:
+ https://docs.travis-ci.com/user/github-oauth-scopes
+
+ (5) Open your Travis CI profile page: https://travis-ci.org/profile
+
+ (6) Enable Travis CI builds for your Git fork.
+
+After the initial setup, Travis CI will run whenever you push new changes
+to your fork of Git on GitHub. You can monitor the test state of all your
+branches here: https://travis-ci.org/<Your GitHub handle>/git/branches
+
+If a branch did not pass all test cases then it is marked with a red
+cross. In that case you can click on the failing Travis CI job and
+scroll all the way down in the log. Find the line "<-- Click here to see
+detailed test output!" and click on the triangle next to the log line
+number to expand the detailed test output. Here is such a failing
+example: https://travis-ci.org/git/git/jobs/122676187
+
+Fix the problem and push your fix to your Git fork. This will trigger
+a new Travis CI build to ensure all tests pass.
+
+
------------------------------------------------
MUA specific hints