nsPrompter could use a few more tests, specifically for checking the default button and default focus in dialogs.

Pushed http://hg.mozilla.org/mozilla-central/rev/d4cfad073452

Backed out due to orange http://hg.mozilla.org/mozilla-central/rev/d0a4697b4b6a Next time don't let your plant review any code :p

Exciting, I was not expecting Linux to be different than Windows and OS X! Will investigate. [Aside: this is why it's good to file bugs even for fairly trivial test-only checkins!]

The failures on Linux are for the window-modal prompts; the focus manager is to be saying nothing is focused (.focusedElement == null), but I'm not sure I believe it (the prompt sure seems to _work_ as if the expected things are focused). So, I'm going to land this test with a todo() that skips the focused element checking on Linux. CC'd Enn, maybe you feel like looking at this some time? [It's just a test, I don't believe this is causing any real-world problems.] Oh, I also tried adding a waitForFocus() callback in prompt_common.js's timer observer, but it was never invoking the callback.

Pushed http://hg.mozilla.org/mozilla-central/rev/6757bf360091

Tests that use modal alert windows frequently fail on Fedora Linux. I'd just leave it for now.