Git commit message guidelines

The first line of the commit message should be a short description (50 characters is the soft limit), should start with a capital letter and should skip the full stop.

The body should provide a meaningful commit message, which:

• uses the imperative, present tense: “change” not “changed” or “changes”. Describe what the effect of applying the change will be, not what you did do make the change.

• includes motivation for the change, and contrasts its implementation with previous behaviour.

• Wrap lines at 72 chars or so

See

• http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html

• http://git.kernel.org/?p=git/git.git;a=blob;f=Documentation/SubmittingPatches;h=ece3c77482b3ff006b973f1ed90b708e26556862;hb=HEAD

• http://365git.tumblr.com/post/3308646748/writing-git-commit-messages

for some justifications on this strategy

An example commit message:

BUG:nnnnn Short summary (around 50 chars)

More detailed explanatory text, if necessary.  Wrap it to about 72
characters or so.  In some contexts, the first line is treated as the
subject of an email and the rest of the text as the body.  The blank
line separating the summary from the body is critical (unless you omit
the body entirely); tools like rebase can get confused if you run the
two together.

Write your commit message in the present tense: "Fix bug" and not "Fixed
bug."  This convention matches up with commit messages generated by
commands like git merge and git revert.

Further paragraphs come after blank lines.

- Bullet points are okay, too

- Typically a hyphen or asterisk is used for the bullet, preceded by a
  single space, with blank lines in between, but conventions vary here

- Use a hanging indent

In order to save a bit of space on the short summary, and to fit the 'present tense' paradigm, I propose that where we previously used FIXED: and FEATURE: we should say FIX: or NEW:. REGRESSION has never been particularly useful (as it doesn't indicate which version it was first broken in) and should be withdrawn. Not sure what I think about INTERNAL: (is there really any such thing any more?)

NOTE: These guidelines refer to the git commit message and not any github comment fields used for discussing a commit, pull-request, or line. The github comment fields do not form part of the project's git history. When submitting a pull request there is no need to put anything in the pull-request's comment field in most cases - the commit messages should already explain the reason for the request. Comments on the pull-request might be useful for such things as "this pull request is dependent on you having taken that other one" or suchlike...