bug#39822: 27.0.90; Cannot set *Completions* buffer height using display-buffer-alist

[Juri Linkov]

>>> You mean 'minibuffer-completion-help' should call 'display-buffer'
>>> directly and do the rest of the setup manually?
>>
>> Yes, and all other commands that currently use
>> with-displayed-buffer-window should get along without it.
>
> OK with me.

Here is a complete list of commands that use
with-displayed-buffer-window:

- dired-mark-pop-up
- minibuffer-completion-help
- save-buffers-kill-emacs

What they all have in common is that they have some post-processing
in the displayed buffer.  I wonder why there are no more such commands
that need to do such post-processing?  Maybe they use some simpler
solution that could be used here as well?

For example, hack-local-variables-confirm uses just

  (pop-to-buffer "*Local Variables*" '(display-buffer--maybe-at-bottom))

and nothing more, without hassles of with-displayed-buffer-window.
And still it fits the window nicely into the buffer height.
Why the above 3 commands couldn't do the same by abandoning
with-displayed-buffer-window?

> So you mean the default value is the value supplied by
> 'display-buffer-alist'.

Actually, I meant the default value is that used as the ACTION arg of
display-buffer.