When moving mouse pointer from an active element to its popover, there is a small area in between which is neither. A different active element is sometimes there, in which case we quickly switch to its popover. This is a correct behavior in general, but it makes it difficult to interact with the popover in some cases. Adding a tiny timeout before switching to another popover should help I think.
Created attachment 220354 [details] WIP patch Seems to work correctly at first glance, but needs more refactoring and testing.
Created attachment 220384 [details] proposed patch
Comment on attachment 220384 [details] proposed patch Clearing flags on attachment: 220384 Committed r161441: <http://trac.webkit.org/changeset/161441>
All reviewed patches have been landed. Closing bug.