We're using a handle that may have been just deleted. Patch forthcoming.
Created attachment 32966 [details] proposed fix
<rdar://problem/7070273>
Comment on attachment 32966 [details] proposed fix I don't have in depth knowledge of the area, but the patch is pretty simple and makes a lot of sense.
This appears to have been landed. Is there a reason that the bug is still open?
No reason. This was committed in <http://trac.webkit.org/changeset/46058>.