A co-worker and I are both working on the master branch at the moment. I have some code in my working tree that I don\'t want to commit (debugging statements and the like). No
Forget everything you ever learned from subversion.
Always commit before introducing external changes.
Imagine you had a mostly-working tree -- maybe not perfect, but you're making some progress. Then you go to do a merge and the code you're bringing in just wreaked havoc (was buggy itself, too many conflicts to deal with, etc...). Wouldn't it be nice if you could just undo that?
If you commit, you can. If you don't, you're just going to suffer.
Remember: What you commit doesn't have to be what you push, but what you don't commit you can easily lose.
Just do the safe and easy thing and commit early and commit often.