Repro: put this in the location field and press return:
Created attachment 219007 [details]
Comment on attachment 219007 [details]
Clearing flags on attachment: 219007
Committed r160515: <http://trac.webkit.org/changeset/160515>
All reviewed patches have been landed. Closing bug.
I suspect that this might have caused bug 126014.
Chris suggested to roll out while he is looking into this. Landed the rollout as <http://trac.webkit.org/r160866>.
Also filed <https://bugs.webkit.org/show_bug.cgi?id=126021> for the general case of using this pattern.