bug#43363: 27.1; Wrapped comment line that contains cyrillic text is displayed in different colors

[Eli Zaretskii]

> Date: Mon, 5 Oct 2020 00:08:10 +0100
> From: Alan Third <alan@idiocy.org>
> Cc: Драгољуб Шишовић <dragoljub.sisovic@gmail.com>,
>       43363@debbugs.gnu.org
> 
> I can reproduce it only with frame-resize-pixelwise set to t and the
> frame not being an exact number of characters wide.

You are right.  After playing with "C-x C-+" a bit, I can see this as
well.

Very strange bug.

Observation #1: It is not some simple redisplay glitch, as "M-x
redraw-display" doesn't fix the problem.  Looks like the region face
and the text face aren't merged properly for some reason.

Observation #2: It doesn't happen only with Cyrillic characters, of
course, it seems to happen with any non-ASCII non-Latin characters.

Observation #3: It never happens in the initial portion of a continued
line, only in the continuation lines.

Hmm...