bug#22549: 25.0.50; Tooltips placed outside of screen limits

[martin rudalics]

> My initial patch is not better because it doesn't protect against the
> possible lack of information on x-display-monitor-attributes-list you
> mentioned above and on your previous e-mail. If that structure has not
> the correct geometry info about the current monitor, the variables
> max/min_x/y are guaranteed to be wrong. My last patch provides some
> protection against that circunstance, so I'll feel better committing it.

I'd still prefer something like

if (CONSP (attributes))
  while (CONSP (attributes))
    ... your new code ...
else
  ... the old code ...

but I leave it to you.  I feel uneasy talking about changes I can't
really test here.

> (BTW, the path is basically yours, not mine. I just corrected some
> issues but the 90% was written by you, so I'll feel a bit uneasy taking
> credit for it.)

80% of my code was stolen from the person who wrote the Windows code.  I
suppose it was Andy Moreton but I can't find the corresponding ChangeLog
entry now.  So don't bother ;-)

>> Have you tried with a frame that spans both monitors?
>
> Just tried. It seems to work fine: for a frame that spawns both
> monitors, the tooltip is correctly positioned taking into account the
> coordinates of the mouse cursor and the geometry of the corresponding
> monitor.

I suppose you tested with underlying text very near the dividing screen
edge.  When you drag the frame with the mouse from left to right and
back does the tooltip "jump" accordingly from one monitor to the other?

martin