The art of commit messages
The commit message is one of the most important tools a developer has: in just a few lines, he can communicate a great deal of information to a great variety of people. This group includes a vast swath of eager but relatively nontechnical users who merely want to know what was improved in the most recent update. Additionally, this group includes a number of technical users who may look at the code from time to time and perhaps submit patches intermittently. This group includes the other developers, who on a larger project may not be entirely aware of everything being worked on. This group even includes the developer himself, as he will probably not remember today’s change in detail a year from now.
So what can a developer do to make a commit message relatively succint but still satisfy the needs of all of these people? Let’s take the commit message I wrote for this year’s most significant patch so far, Holger’s overhaul of a large part of x264′s most important assembly code.