active items in window list miscoloured by overlaps

[Martin Erik Werner]

When active items in the window list are overlapped by tooltips or dropped menus, the colour of the overlapped area changes to the non-active colour and remains so after the overlapping item is gone.
Hence window list items ends up half-coloured in some cases.
If item is completely covered by a tooltip or a menu, or if the item is activated (mouse-over) the miscolouring goes away, though comes back if overlap is repeated.

TEST CASE:
Using Firefox Downloads window:
1. Launch firefox
2. Open FIrefox Downloads window
3. Focus on Firefox window and download something
4. Once download is finished, wait for the Downloads window-list item to stop flashing (~5s), it should now be highlighted & in bold text
5. Overlap the Downloads window-list item PARTLY with a tooltip or dropped menu
6. Leave tooltip/menu

* window-list item is not highlighted where the overlap was
! Expected item to go back to highlighted colour where the overlap was

Screenshot of half-coloured item attached

[Martin Erik Werner (arand)]

Video showing miscolouring with tooltip overlap

[Wayno (ichabod)]

Might be nvidia related. seems okay with the stock ati driver.

[Martin Erik Werner (arand)]

Might be metacity-related, since seen on VirtualBox instance & proper install running on nvidia blob.
adding metacity task

[Martin Erik Werner (arand)]

And on nouveau as well (with metacity)

[Martin Erik Werner (arand)]

Problem seen on Karmic with nvida blob as well.
No regression

[Pedro Villavicencio (pedro)]

Thanks for sent this upstream.