The page in the URL uses document.getBoxObjectFor (or falls back on the IE extension getBoundingClientRect which isn't implemented in WebKit either) for submenu positioning. I couldn't find any official information on getBoxObjectFor.
Firefox has exposed getBoxObjectFor by accident: https://bugzilla.mozilla.org/show_bug.cgi?id=340571
Given that this already leaked, I'm not 100% sure that it's a good idea to remove it :-(
(In reply to comment #2) > Given that this already leaked, I'm not 100% sure that it's a good idea to > remove it :-( Reopened. My own opinion is that WebKit should not implement getBoxObjectFor.
We should implement getBoundingClientRect() (on HTMLElement), IMHO. IMHO getBoxObjectFor() should not be implemented.
It absolutely should not be implemented.
getBoundingClientRect would be reasonable I suppose.