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

[Gerd Möllmann]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Gerd Möllmann <gerd.moellmann@gmail.com>
>> This is because 'write' deliberatly leaves the bottom-right corner alone
>> if the terminal has "auto right margin" (autowrap).
>
> But AFAIU, the bug actually shows that we somehow _do_ write there,
> although the display engine assumes we don't.  Right?

My theory is that no-one but tty_write_glyphs knows that it didn't write
to the bottom-right corner.  At least so far I couldn't find code that
takes this into account.