bug#56393: Actually fix the long lines display bug

[Eli Zaretskii]

> Date: Mon, 18 Jul 2022 14:10:10 +0000
> From: Gregory Heytings <gregory@heytings.org>
> cc: gerd.moellmann@gmail.com, larsi@gnus.org, 56393@debbugs.gnu.org
> 
> >> I guess it's better, as it reduces the number of cases where the 
> >> problem could happen, at the price of making those cases slower.
> >
> > Okay, I'll push that.  It seems to work as well.
> >
> 
> Done.  Can you please check that the earlier segfaults are still gone?

Still gone.