This is an easily reproducible bug.
Created attachment 303847 [details] WIP I've got some other random stuff I need to remove still.
Created attachment 303889 [details] patch
Comment on attachment 303889 [details] patch Clearing flags on attachment: 303889 Committed r213653: <http://trac.webkit.org/changeset/213653>
All reviewed patches have been landed. Closing bug.