bug#52385: 29.0.50; Doc-View can't view separate pages in separate windows

[Eli Zaretskii]

> From: Juri Linkov <juri@linkov.net>
> Date: Thu, 16 Dec 2021 19:04:12 +0200
> Cc: 52385@debbugs.gnu.org
> 
> But the regression is in overlay window priorities:
> when two overlays with 'window' properties are added
> over the same region, then in 27.2 the overlay where
> the overlay window matches the selected window is preferred
> over the overlay with another window.  But in 28.0.90
> the first overlay always wins.

If you don't assign priorities to overlays, you cannot expect any
particular order of their preferences.  It depends on random factors
you cannot control.  The window property only filters candidate
overlays, it doesn't affect their priorities for affecting the
display.