bug#43519: 28.0.50; Overlay at end of minibuf hides minibuf's real content

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: Gregory Heytings <ghe@sdf.org>,  43519@debbugs.gnu.org
> Date: Mon, 21 Sep 2020 13:28:59 -0400
> 
> Eli Zaretskii [2020-09-21 17:17:23] wrote:
> > For example: would it be okay to start the display at
> > the beginning of the screen line where we end up after
> > move_it_vertically_backward returns?
> 
> Sounds reasonable.

Thanks.  if this is agreed upon, I will try to come up with a (tested)
patch.

> Do we have something like tests (or at least a list of recipes to
> try) so we can catch regressions?

Not for the mini-window display, I'm afraid.

> It seems this part of the code is trying to satisfy needs which
> aren't clearly expressed anywhere, so while this suggestion may
> sound good to me (just like the patch I just sent), I'm afraid it
> will bring back other problems.

That's a risk, yes.  That's why I prefer "small changes", i.e. changes
that aren't supposed to affect scenarios unrelated to the ones
discussed.