Created attachment 250607 [details]
I’ve had Safari’s “DFG Worklist Worker Thread” crash Safari (8.0.5 on 10.10.3) twice. The last time I was typing into a text field (ironically at bugreport.apple.com), loosing my already typed text.
Thread 15 Crashed:: DFG Worklist Worker Thread
Also filed rdar://20512791
Created attachment 250608 [details]
crash report 2
Can you reproduce this failure @ bugreport.apple.com?
Are both crash reports from bugreport.apple.com, or is there another URL we should try to reproduce this bug?
No, I can't reproduce this at all and I don't know that if this has anything to do with bugreport.apple.com, though I can't rule it out either. The first crash definitely wasn't while bugreport.apple.com was the active tab, though it could be that it was in some tab in the background.
At the time of the 2 crashes I had somewhat between 10 and 20 tabs open, some of them could be executing js in the background.
I have no idea how I could relate the crash to one of the tabs.
I suspect that this is fixed by the change to <https://bugs.webkit.org/show_bug.cgi?id=143727> - "DFG register fillSpeculate*() functions should validate incoming spill format is compatible with requested fill format" which was landed in change set r182827: <http://trac.webkit.org/changeset/182827>.
It is hard to prove if we can't reproduce the crash.
Thank you Michael. Should I encounter the crash again, I will note all open URLs so I can try to reproduce, and let you know.
However, the crash seems pretty rare, as I'm having Safari open almost all day long and using it heavily, but encountered it only those 2 times I have the crash logs attached.
Haven't come across this since then, marking as resolved.