bug#32825: 27.0.50; Deterministic window management

[Juri Linkov]

>> Maybe I misunderstand something, but I see that already everything is
>> working fine.  When I tried with display-buffer-below-selected
>> to cause an error in a narrow buffer at the bottom of the frame,
>> then the *Backtrace* buffer is displayed in a new window created
>> by horizontal splitting of the largest window on the frame.
>
> I never doubted that it works correctly (IIRC Michael did).  But from
> what you tell above it's obvious that you tried with customizations of
> the initial frame size which cause 'split-window-sensibly' to prefer a
> horizontal split over a vertical one.  Right?  If so, then since most
> users of Emacs do not have such customizations, your invocation hardly
> qualifies as of the emacs -Q type.

I tried in a wide frame, but trying in a narrow frame is even better:
it selects a large window without splitting it.

What is much worse is that subsequent calls in a narrow frame
display the *Backtrace* buffer each time in another window -
the window is not reused where it was displayed previously.