Created attachment 39476 [details]
On the page that is served after logging into americanexpress.com, there are drop down menus at the top of the page. After http://trac.webkit.org/changeset/47440, they can easily disappear on mouse out. before that change, one could slowly move the mouse below the menu and access the submenu, but now you have to move quickly in order for the menu not to disappear on you.
Bug is observable on Windows, but not on Mac. Reduction attached.
Created attachment 40316 [details]
The reduction text should say “green” instead of “yellow”.
Created attachment 40323 [details]
Include self-painting inlines in line box overflow
Perhaps there is a more elegant and efficient solution (note that this extends r47798), but in practice I think this is fine.
Fixed in <http://trac.webkit.org/projects/webkit/changeset/48947>