The regression was introduced in r60169.
Created attachment 58005 [details] Patch
Comment on attachment 58005 [details] Patch Clearing flags on attachment: 58005 Committed r60772: <http://trac.webkit.org/changeset/60772>
Revision r60772 cherry-picked into qtwebkit-2.0 with commit ad3e72a151dc7a98a9d7158cffabf1f020fe5ea5