Zooming back near the bottom or top of the document can lead to over-scrolling because the restored position is not bound by document size at the correct zooming level.
Created attachment 138793 [details] Patch
Comment on attachment 138793 [details] Patch Clearing flags on attachment: 138793 Committed r115193: <http://trac.webkit.org/changeset/115193>
All reviewed patches have been landed. Closing bug.