Created attachment 631873 [details] [diff] [review] Patch v1 No idea what the effects are, but I reckon it has some.
It's not clear why this is flagged for tracking - can we get an idea of the impact of this bug? A regression range?
roc - is this a worthwhile uplift to FF15? Any risks here, or perhaps we should consider backing out bug 749075?
Untracking for 15 unless someone wants to come and pitch why we should consider for uplift.