bug#43702: Emacs master: Incorrect highlighting in regexp isearch.

[Eli Zaretskii]

> Date: Tue, 29 Sep 2020 12:13:17 +0000
> From: Alan Mackenzie <acm@muc.de>
> Cc: acm@muc.de
> 
> In the Emacs master branch
> (i) emacs -Q
> (ii) C-x C-f emacs/src/syntax.c<CR>
> (iii) C-M-s \(inc\|dec\)_both
> (iv) Press C-s a few times.
> 
> Notice that the highlighting of the found match has the purple
> background over the correct characters, but the characters displayed in
> the foreground are "   _both".  This incorrect display is a bug.

Here, I don't see any incorrect display, I see a new feature at work.
If you don't like it, set search-highlight-submatches to nil.

How many colors do you have on the terminal where you see the problem?