When I go to check code into a Subversion repository, I like to review a diff of my changes. I can confirm I’m committing the right files, make sure I didn’t leave in any debugging statements, and take one last chance to ponder the code. Usually this means doing an svn diff in another window or shelling out of vim to run it. This is a bit awkward, so it’s easy to forget the step. That’s backwards, it should be easier to do things right than slack.