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

[Eli Zaretskii]

> From: Драгољуб Шишовић <dragoljub.sisovic@gmail.com>
> Date: Sat, 12 Sep 2020 20:57:17 +0200
> 
> Expected behavior:
> When a single line comment that is wrapped gets selected (or when cursor is 
> positioned on that line) text
> color should be the one defined with the emacs color theme.
> 
> Detected behavior:
> Instead of expected behavior text is colored partially as a comment and 
> partially as a regular text.

This is very strange.  I cannot reproduce this on my system, so the
reason is somehow specific to what you have there.

You didn't show the details collected by report-emacs-bug, so it's
hard to make educated guesses regarding the most probable reasons.
Therefore, what's below are stabs in the dark:

 . does it help to disable double-buffering?
 . if this is a Cairo build, can you try --without-cairo?
 . if you have some advanced optimization features of your system's
   display software turned on, try turning them off

Also, what was the Emacs version before the upgrade to 27.1?

Thanks.