bug#31880: 26.1; VC mode line popup when clicked is off screen

[martin rudalics]

> I am using a high resolution display (built-in Retina display on a MacBook 
Pro).
> I have the scaling set to 200%. When I change to 100%, the popup works fine. 
When
> I change to LoDPI mode, the popup works fine. It definitely seems to be an 
issue
> with scaled HiDPI.

Thanks for the information.  Please keep 31880@debbugs.gnu.org cc'ed.

Robert what do you think?  create_and_show_popup_menu has

#ifdef HAVE_GTK3
      /* Use window scaling factor to adjust position for hidpi screens. */
      x /= xg_get_scale (f);
      y /= xg_get_scale (f);
#endif

Shouldn't this take of Brian's problem?  If not, could you tell him
how to debug this?

Thanks, martin