bug#20677: tooltips generate garbage

[Eli Zaretskii <eliz@gnu.org>]

> Date: Tue, 02 Jun 2015 11:35:02 +0200
> From: Angelo Graziosi <angelo.graziosi@alice.it>
> CC: 20677@debbugs.gnu.org
> 
> > Attached. (Schermata2.png is with "emacs -Q &")
> 
> Just for clarification...
> 
> When I move the mouse pointer over an icon which has a tooltip, this is 
> shown correctly. It is when I move the pointer so that the tooltip 
> should be "closed" that it, partially, remains as shown by screenshots I 
> sent.

Yes, that's what I deduced from your screenshots, thanks.

So it probably means the problem is with x-hide-tip, not with
x-show-tip.  Somehow, we don't redraw the parts of the frame that were
overlaid with the tooltip, when the tip pops down, and the artifacts
from the tooltip display stay on screen.

Does Emacs clean up the display if you type "M-x redraw-display RET"
after the tip pops down?  What about covering the frame with the tip
artifacts with another frame, then uncovering it -- does the frame get
redrawn automatically, and does that remove the artifacts?

Finally, can you try setting x-gtk-use-system-tooltips to nil, and see
if that makes the problem go away?