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

[martin rudalics]

> I don't think that performance considerations are applicable here. About
> compromising the one monitor case: in theory, the monitor's geometry is
> always the right thing to use for calculating the tooltip position, not
> x_display_pixel_width/height. For instance: it is possible to configure
> X for having a desktop area larger than the monitor's resolution, IIRC.

But ‘x_display_pixel_height’ returns the value of 'HeightOfScreen' which
is what we need for the one monitor case.

>> There's no guarantee that ‘x-display-monitor-attributes-list’ works on
>> all systems, especially on those where neither Xinerama nor XRandr are
>> installed.  IIRC older versions of the latter might also have problems
>> when a monitor is added/removed during a session.  The fallback should
>> always give the same results as the present code, but who knows ...
>
> See the attached patch. If we can't use the monitor's geometry, we
> default to the old code.

My concern was less that ‘x-display-monitor-attributes-list’ would not
assign a value to max_y.  My concern was that that value could be wrong.

Anyway.  Better install your initial patch then.  It's cleaner and we'll
see soon enough whether it causes any problems.

>> And just to make sure: Can we rely on the fact that XQueryPointer always
>> gives reliable results with multiple monitors and its present arguments?
>
> Dunno. I know nothing about X Windows.

Have you tried with a frame that spans both monitors?

martin