When nsOggDecodeStateMachine decodes all of a video and moves to COMPLETED state, after it's played the last frame it sets an async callback to nsOggDecoder::PlaybackEnded(). nsOggDecodeStateMachine then goes into a loop while it's waiting for PlaybackEnded() to Stop() and shut it down. If there is a pending JS timeout which does a seek which runs after the PlaybackEnded() callback is set, but before the PlaybackEnded() callback fires, the seek will not trigger, and its seeking/seeked events won't fire either. This could cause intermittent test timeouts, if a testcase is seeking a playing media and relies on a seeking/onseeked event in order to terminate. The problem is that the loop in nsOggDecodeStateMachine::Run() COMPLETED case which waits for PlaybackEnded to shut down the state machine loops while (mState != SHUTDOWN). The state machine will be in COMPLETED state. Then nsOggDecoder::Seek() changes state the state machine's state to SEEKING, but when PlaybackEnded() fires it just overwrites the state with SHUTDOWN, obliterating the seek. One solution: * Change the while (mState != SHUTDOWN) loop in nsOggDecodeStateMachine::Run() COMPLETED case to while (mState == COMPLETED), and have PlaybackEnded bail out if (nsOggDecoder::mPlayState != SEEKING).

Test case. Just run it, and eventually it will stop counting down. Check the log and you'll see that a seek was started, but ended was fired which canceled the seek.

Solution as described in comment 1.

Comment on attachment 352456 [details] [diff] [review] Patch v1 [Checkin: Comment 3 & 4] http://hg.mozilla.org/mozilla-central/rev/3633177885d6

Comment on attachment 352456 [details] [diff] [review] Patch v1 [Checkin: Comment 3 & 4] http://hg.mozilla.org/releases/mozilla-1.9.1/rev/8f5515472d73

verified FIXED on builds: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2a1pre) Gecko/20090422 Minefield/3.6a1pre ID:20090422044118 and Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b4pre) Gecko/20090422 Shiretoko/3.5b4pre ID:20090422042031