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

[Eli Zaretskii]

> Date: Sun, 20 Sep 2020 08:27:55 +0000
> From: Gregory Heytings <ghe@sdf.org>
> cc: 43519@debbugs.gnu.org
> 
> But the point is that there is clearly enough horizontal space, so there 
> is (or there does not seem to be) no reason to scroll horizontally.

There's no horizontal scroll.  What happens is that Emacs decides that
the mini-window's display will start at EOB.  I hope I've explained
why this happens in my previous message.

> > You are asking the display engine to do the impossible.
> 
> No.  With a minibuffer-only frame, the bug is not present.

With a minibuffer-only frame, mini-window resizing works very
differently: it resizes the entire frame.

> So it's feasible, and the display engine knows how to do it.

I'm sure we will welcome patches to make this happen in the other
cases.