bug#21173: 25.0.50; New frames positioned off screen with multiple monitors

[Francis Litterio <flitterio@gmail.com>]

martin rudalics <rudalics <at> gmx.at> writes:

> 
>  > Function x_calc_absolute_position does not account for the fact
>  > that my left monitor's left offsets are negative.  I believe that
>  > is the root of the bug.
> 
> If `display-monitor-attributes-list' returns the correct geometry 
values
> it shouldn't be too hard to fix this.

Thanks, Martin.  I see display-monitor-attributes-list return
this value:

  (((geometry 0 0 1920 1080)
    (workarea 0 0 1920 1080)
    (mm-size 677 381)
    (name . "\\\\.\\DISPLAY1")
    (frames #<frame emacs - Izsystem023 - *Buffer List* 06e2fad8>))
   ((geometry -1920 0 1920 1080)
    (workarea -1920 0 1920 1080)
    (mm-size 677 381)
    (name . "\\\\.\\DISPLAY2")
    (frames)))

Note the "-1920" in the info for DISPLAY2.  So I think all
the information is there to fix this.

> That is, after the final
> calculation of f->left_pos in x_calc_absolute_position subtract from 
it
> the value (if negative) of whatever 
w32_display_monitor_attributes_list
> returns as first value in `geometry' and from f->top_pos the second
> value.

I could do this in pure Elisp, but x_calc_absolute_position is
written in C, and I'm weak at using Elisp functions and objects
from C.  I'll give it a try and re-test.  If I get something
working, I'll post the patch here for review.
--
Fran