I've discovered a tiny bug in Iceweasel yesterday, and I decided to fix it myself. So I'm proud to have opened bug #494694 against xulrunner with a patch!
That bring me to the tip of the day: if you are bored, I suggest you compile xulrunner and keep looking at the build log while it's building. There's so much gcc warnings that you'll get enthousiastic thinking:
« Argh, it'll fail… Oh no! That was just a bunch of warnings! Ahah this time it'll fail! Shit, just 764 warnings again in a row. Not so bad… ».