bug#34516: Multi-monitor frame sets

[Juri Linkov]

>> > What kind of list does display-monitor-attributes-list return on your
>> > system, and how can you tell which part there refers to what physical
>> > monitor?
>> 
>> It returns a list with such meaningless monitor names as “LVDS”, “eDP-1”, 
>> “DP-2-2”,
>> etc. that don't help to refer to a physical monitor.  However, I noticed that
>> the only attribute that could help is ‘geometry’ in the form of (X Y WIDTH 
>> HEIGHT),
>> e.g. when two adjacent monitors have such geometry attributes:
>> 
>>   (geometry    0  0 1920 1080)
>>   (geometry 1920 16 2560 1440)
>> 
>> the right edge of the first monitor ends (1920px) is where the left edge
>> of the second monitor begins.  Based on this guess I tried to deduce
>> a relative placement of new frames, but maybe I'm wrong.
>
> Does the proposed function sound useful, given these issues?

The proposed function tries to provide the right geometry for
‘make-frame’, i.e. the geometry of the selected monitor, but I see
that it doesn't always makes a new frame on the specified monitor.
Also I don't understand the logic how currently ‘make-frame’ decides
on which monitor to make a new frame.