Re: "Final" version of tty child frames

[Gerd Möllmann]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Gerd Möllmann <gerd.moellmann@gmail.com>
>> Cc: rudalics@gmx.at,  jared@finder.org,  emacs-devel@gnu.org
>> Date: Fri, 17 Jan 2025 08:50:58 +0100
>> 
>> There might be another problem. Feng Shu, the author of Posframe,
>> reported a problem with child frames over Chinese text at some point:
>> 
>>   https://yhetil.org/emacs-devel/m25xpji82g.fsf@gmail.com/
>> 
>> In short, this handles the case that a child frame overlaps a
>> double-width character, in the sense that one half of the displayed
>> character is outside of the child frame, and the other half is under the
>> child frame.
>
> Didn't you already fix that problem in the past, when child frames on
> TTYs were first introduced?
>
> What should happen in this case is that we don't show the double-width
> character at all.

Yes it's fixed, and the fix is the problem. It modifies the root's
current matrix outside of the area that a child occupies, by changing
glyphs to padding glyphs.

I've made me a branch now for the terminal matrices. Can take a bit,
though :-/.