bug#44070: 28.0.50; Minibuffer display "jumps" upon minor edit

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: 44070@debbugs.gnu.org
> Date: Sun, 01 Nov 2020 10:38:03 -0500
> 
> > I thought about testing equality between the window being redisplayed
> > and minibuf_window.  We could also look at the buffer displayed by the
> > window, and see if it appears in Vminibuffer_list.  Does that make
> > sense?
> 
> Sounds pretty ugly.

??? Why?  In any case, we do this stuff all over the place.  A random
example:

      else if ((w != XWINDOW (minibuf_window)
                || minibuf_level == 0)
               /* When buffer is nonempty, redisplay window normally.  */
               && BUF_Z (XBUFFER (w->contents)) == BUF_BEG (XBUFFER 
(w->contents))
               /* Quail displays non-mini buffers in minibuffer window.
                  In that case, redisplay the window normally.  */
               && !NILP (Fmemq (w->contents, Vminibuffer_list)))