bug#56682: feature/improved-locked-narrowing 9dee6df39c: Reworked locked narrowing.

[Eli Zaretskii]

> From: Juri Linkov <juri@linkov.net>
> Cc: gregory@heytings.org,  56682@debbugs.gnu.org,  monnier@iro.umontreal.ca
> Date: Mon, 30 Jan 2023 19:56:44 +0200
> 
> I noticed this problem only in one commit last week, but didn't realize
> it's caused by long lines.  I had time to debug it only today.
> Now could try to create a minimal test case.

Thanks, please do.