- check for unnecessary whitespace with "git diff --check"
before committing
- do not check in commented out code or unneeded files
- - provide a meaningful commit message
- the first line of the commit message should be a short
- description and should skip the full stop
- - if you want your work included in git.git, 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
+ description (50 characters is the soft limit, see DISCUSSION
+ in git-commit(1)), and should skip the full stop
+ - 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
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:
here on the technical/contents front, because the core GIT is
thousand times smaller ;-). So here is only the relevant bits.
+(0) Decide what to base your work on.
+
+In general, always base your work on the oldest branch that your
+change is relevant to.
+
+ - A bugfix should be based on 'maint' in general. If the bug is not
+ present in 'maint', base it on 'master'. For a bug that's not yet
+ in 'master', find the topic that introduces the regression, and
+ base your work on the tip of the topic.
+
+ - A new feature should be based on 'master' in general. If the new
+ feature depends on a topic that is in 'pu', but not in 'master',
+ base your work on the tip of that topic.
+
+ - Corrections and enhancements to a topic not yet in 'master' should
+ be based on the tip of that topic. If the topic has not been merged
+ to 'next', it's alright to add a note to squash minor corrections
+ into the series.
+
+ - In the exceptional case that a new feature depends on several topics
+ not in 'master', start working on 'next' or 'pu' privately and send
+ out patches for discussion. Before the final merge, you may have to
+ wait until some of the dependent topics graduate to 'master', and
+ rebase your work.
+
+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.
(1) Make separate commits for logically separate changes.
commit message and generate a series of patches from your
repository. It is a good discipline.
-Describe the technical detail of the change(s).
+Give an explanation for the change(s) that is detailed enough so
+that people can judge if it is good thing to do, without reading
+the actual patch text to determine how well the code does what
+the explanation promises to do.
If your description starts to get too long, that's a sign that you
probably need to split up your commit to finer grained pieces.
+That being said, patches which plainly describe the things that
+help reviewers check the patch, and future maintainers understand
+the code, are the most beautiful patches. Descriptions that summarise
+the point in the subject well, and describe the motivation for the
+change, the approach taken by the change, and if relevant how this
+differs substantially from the prior version, are all good things
+to have.
Oh, another thing. I am picky about whitespaces. Make sure your
changes do not trigger errors with the sample pre-commit hook shipped
(1a) Try to be nice to older C compilers
-We try to support wide range of C compilers to compile
+We try to support a wide range of C compilers to compile
git with. That means that you should not use C99 initializers, even
if a lot of compilers grok it.
(2) Generate your patch using git tools out of your commits.
-git based diff tools (git, Cogito, and StGIT included) generate
-unidiff which is the preferred format.
+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
that starts with '-----BEGIN PGP SIGNED MESSAGE-----'. That is
not a text/plain, it's something else.
-Note that your maintainer does not necessarily read everything
-on the git mailing list. If your patch is for discussion first,
-send it "To:" the mailing list, and optionally "cc:" him. If it
-is trivially correct or after the list reached a consensus, send
-it "To:" the maintainer and optionally "cc:" the list for
-inclusion.
-
-Also note that your maintainer does not actively involve himself in
-maintaining what are in contrib/ hierarchy. When you send fixes and
-enhancements to them, do not forget to "cc: " the person who primarily
-worked on that hierarchy in contrib/.
+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
+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.
(4) Sign your work
place an in-body "From: " line at the beginning to properly attribute
the change to its true author (see (2) above).
-Some people also put extra tags at the end.
+Also notice that a real name is used in the Signed-off-by: line. Please
+don't hide your real name.
+
+If you like, you can put extra tags at the end:
+
+1. "Reported-by:" is used to credit someone who found the bug that
+ the patch attempts to fix.
+2. "Acked-by:" says that the person who is more familiar with the area
+ the patch attempts to modify liked the patch.
+3. "Reviewed-by:", unlike the other tags, can only be offered by the
+ reviewer and means that she is completely satisfied that the patch
+ is ready for application. It is usually offered only after a
+ detailed review.
+4. "Tested-by:" is used to indicate that the person applied the patch
+ and found it to have the desired effect.
-"Acked-by:" says that the patch was reviewed by the person who
-is more familiar with the issues and the area the patch attempts
-to modify. "Tested-by:" says the patch was tested by the person
-and found to have the desired effect.
+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:".
------------------------------------------------
An ideal patch flow
their trees themselves.
------------------------------------------------
-MUA specific hints
+Know the status of your patch after submission
-Some of patches I receive or pick up from the list share common
-patterns of breakage. Please make sure your MUA is set up
-properly not to corrupt whitespaces. Here are two common ones
-I have seen:
+* You can use Git itself to find out when your patch is merged in
+ master. 'git pull --rebase' will automatically skip already-applied
+ patches, and will let you know. This works only if you rebase on top
+ of the branch in which your patch has been merged (i.e. it will not
+ tell you if your patch is merged in pu if you rebase on top of
+ master).
-* Empty context lines that do not have _any_ whitespace.
+* 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.
-* Non empty context lines that have one extra whitespace at the
- beginning.
-
-One test you could do yourself if your MUA is set up correctly is:
-
-* Send the patch to yourself, exactly the way you would, except
- To: and Cc: lines, which would not contain the list and
- maintainer address.
-
-* Save that patch to a file in UNIX mailbox format. Call it say
- a.patch.
-
-* Try to apply to the tip of the "master" branch from the
- git.git public repository:
-
- $ git fetch http://kernel.org/pub/scm/git/git.git master:test-apply
- $ git checkout test-apply
- $ git reset --hard
- $ git am a.patch
-
-If it does not apply correctly, there can be various reasons.
+------------------------------------------------
+MUA specific hints
-* Your patch itself does not apply cleanly. That is _bad_ but
- does not have much to do with your MUA. Please rebase the
- patch appropriately.
+Some of patches I receive or pick up from the list share common
+patterns of breakage. Please make sure your MUA is set up
+properly not to corrupt whitespaces.
-* Your MUA corrupted your patch; "am" would complain that
- the patch does not apply. Look at .git/rebase-apply/ subdirectory and
- see what 'patch' file contains and check for the common
- corruption patterns mentioned above.
+See the DISCUSSION section of git-format-patch(1) for hints on
+checking your patch by mailing it to yourself and applying with
+git-am(1).
-* While you are at it, check what are in 'info' and
- 'final-commit' files as well. If what is in 'final-commit' is
- not exactly what you would want to see in the commit log
- message, it is very likely that your maintainer would end up
- hand editing the log message when he applies your patch.
- Things like "Hi, this is my first patch.\n", if you really
- want to put in the patch e-mail, should come after the
- three-dash line that signals the end of the commit message.
+While you are at it, check the resulting commit log message from
+a trial run of applying the patch. If what is in the resulting
+commit is not exactly what you would want to see, it is very
+likely that your maintainer would end up hand editing the log
+message when he applies your patch. Things like "Hi, this is my
+first patch.\n", if you really want to put in the patch e-mail,
+should come after the three-dash line that signals the end of the
+commit message.
Pine
it.
-Thunderbird
------------
-
-(A Large Angry SCM)
+Thunderbird, KMail, GMail
+-------------------------
-Here are some hints on how to successfully submit patches inline using
-Thunderbird.
-
-This recipe appears to work with the current [*1*] Thunderbird from Suse.
-
-The following Thunderbird extensions are needed:
- AboutConfig 0.5
- http://aboutconfig.mozdev.org/
- External Editor 0.7.2
- http://globs.org/articles.php?lng=en&pg=8
-
-1) Prepare the patch as a text file using your method of choice.
-
-2) Before opening a compose window, use Edit->Account Settings to
-uncheck the "Compose messages in HTML format" setting in the
-"Composition & Addressing" panel of the account to be used to send the
-patch. [*2*]
-
-3) In the main Thunderbird window, _before_ you open the compose window
-for the patch, use Tools->about:config to set the following to the
-indicated values:
- mailnews.send_plaintext_flowed => false
- mailnews.wraplength => 0
-
-4) Open a compose window and click the external editor icon.
-
-5) In the external editor window, read in the patch file and exit the
-editor normally.
-
-6) Back in the compose window: Add whatever other text you wish to the
-message, complete the addressing and subject fields, and press send.
-
-7) Optionally, undo the about:config/account settings changes made in
-steps 2 & 3.
-
-
-[Footnotes]
-*1* Version 1.0 (20041207) from the MozillaThunderbird-1.0-5 rpm of Suse
-9.3 professional updates.
-
-*2* It may be possible to do this with about:config and the following
-settings but I haven't tried, yet.
- mail.html_compose => false
- mail.identity.default.compose_html => false
- mail.identity.id?.compose_html => false
-
-(Lukas Sandström)
-
-There is a script in contrib/thunderbird-patch-inline which can help
-you include patches with Thunderbird in an easy way. To use it, do the
-steps above and then use the script as the external editor.
+See the MUA-SPECIFIC HINTS section of git-format-patch(1).
Gnus
----
whitespaces (fatal in patches). Running 'C-u g' to display the
message in raw form before using '|' to run the pipe can work
this problem around.
-
-
-KMail
------
-
-This should help you to submit patches inline using KMail.
-
-1) Prepare the patch as a text file.
-
-2) Click on New Mail.
-
-3) Go under "Options" in the Composer window and be sure that
-"Word wrap" is not set.
-
-4) Use Message -> Insert file... and insert the patch.
-
-5) Back in the compose window: add whatever other text you wish to the
-message, complete the addressing and subject fields, and press send.