bug#32825: 27.0.50; Deterministic window management

[martin rudalics]

>> (1) Decide whether a specific window can be (re-)used.  Should we
>> refute it when the window cannot be enlarged to 'min-height' lines?
>> The decision would have to be made via 'window-resizable-p' and its
>> IGNORE argument set to the window itself so we can, for example,
>> (re-)use a preserved size window showing some other buffer.
>>
>> (2) Actually resize that window via a 'window-height' entry.  This is
>> independent from (1).  Processing a 'window-height' entry is just some
>> sort of bonus work 'display-buffer' does for the convenience of the
>> user.  It in now way affects the decision which window is chosen.
>>
>> So please think of any bad consequences of what we decide in (1) like
>> not using _any_ window on the selected frame because none of them fits
>> the 'min-height' constraint.  Consider a default two windows frame
>> where the size of the selected window is preserved.
>
> Maybe simply display the buffer in the below window regardless of its
> size?  Because it makes no sense for display-buffer-below-selected to
> display the buffer in a window other than below.

But then the same argument holds for popping up a new window.  Even
if we can't make the new window as large as we want, popping it up
below the selected one is the only thing that makes sense if the
selected window is at the bottom of the frame.  Unless we decide that
failing should be better than not making the window high enough.

martin