Writing good commit messages

1. Introduction
2. The seven rules of a great git commit message
3. References

1. Introduction

Good commit messages serve at least three important purposes:

• To speed up the reviewing process.
• To help write a good release note.
• To help the future maintainers to find out why a particular change was made to the code or why a specific feature was added.

2. The seven rules of a great git commit message

1. Separate subject from body with a blank line.
2. Limit the subject line to 50 characters.
3. Capitalize the subject line.
4. Do not end the subject line with a period.
5. Use the imperative mood in the subject line.
6. Wrap the body at 72 characters.
7. Use the body to explain what and why vs. how.

For example (from http://git-scm.com/book/ch5-2.html):

Short (50 chars or less) summary of changes

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.

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

If you use an issue tracker, put references to them at the bottom,
like this:

Resolves: #123
See also: #456, #789

3. References

The following blog post has a nice discussion of commit messages:

• http://chris.beams.io/posts/git-commit/