bug#57728: 29.0.50; Emacs writes wrong glyph at the bottom-right corner of text terminals

[Gerd Möllmann]

Andreas Schwab <schwab@suse.de> writes:

> On Sep 12 2022, Eli Zaretskii wrote:
>
>> But AFAIU, the bug actually shows that we somehow _do_ write there,
>> although the display engine assumes we don't.  Right?
>
> I think it is the other way round.  The display engine doesn't know that
> sometimes the last character isn't written, and thus does not bother to
> redraw it if the bottom line is scrolled up.

Yes, something like that.