bug#69983: Use category for display-buffer-alist

[Juri Linkov]

>> > If we want to enable user control of displaying warnings, we will have
>> > to add an option for that, because currently that cannot be
>> > controlled.  display-buffer-alist is inappropriate for such control,
>> > since in some cases warnings are not displayed in pop-up windows.
>>
>> Could you show an example when warnings are not displayed in pop-up windows.
>
> The two calls to 'message' there.

These calls are irrelevant.  It makes no sense to add an option
to display text "at the bottom of 'message'".

>> > Thanks, but what do you mean by "at the bottom"?  Can you describe
>> > that place more precisely?
>>
>> Here is an example:
>
> I understand what this means in the simple cases, but not necessarily
> what happens in more complex cases.

This case is not simple.  It demonstrates the problem
in horizontally split windows.

> This is why I asked for a detailed definition of "at bottom".

The detailed definition is in the documentation of
'display-buffer-at-bottom'.