Comment 8 for bug 1134409

It's both - binary and using imagelib.

I haven't been able to reproduce it at all. But IIUC the trace suggests that the observer has been freed already, and when I checked if this could happen in our addon I realized that we're calling imgIRequest::Cancel() when releasing our only reference to the imgINotificationObserver. I guess this is likely to cause these types of crashes? I don't know why this hasn't shown up before, seeing as it's been like it for nearly 2 years :/

I wish we could catch these issues sooner. We have our (Ubuntu) crash reports appear in Socorro for release builds, but the crash reports from the beta builds we provide aren't exposed in the UI (presumably there is some server side magic to map a build ID to a particular beta milestone, eg 20.0b1)

Eg, https://crash-stats.mozilla.com/topcrasher/byos/Firefox/20.0b1/Linux/7/browser shows crashes for the Mozilla builds, but you need to manually hunt for crashes in "20.0" to find ours:

https://crash-stats.mozilla.com/query/query?product=Firefox&version=Firefox%3A20.0&platform=linux&range_value=1&range_unit=weeks&date=02%2F27%2F2013+17%3A49%3A10&query_search=signature&query_type=contains&query=&reason=&build_id=&process_type=any&hang_type=any&do_query=1

Is there anything we can do to fix this?