bug#56393: Actually fix the long lines display bug

[Eli Zaretskii]

> Cc: gerd.moellmann@gmail.com, larsi@gnus.org, 56393@debbugs.gnu.org
> Date: Mon, 18 Jul 2022 21:56:44 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> 
> > Date: Mon, 18 Jul 2022 18:26:22 +0000
> > From: Gregory Heytings <gregory@heytings.org>
> > cc: gerd.moellmann@gmail.com, larsi@gnus.org, 56393@debbugs.gnu.org
> > 
> > 
> > >> Thanks, but couldn't we use the existing BUF_CHARS_MODIFF for that?
> > >
> > > I'll have a look, thanks.
> > >
> > 
> > And the answer is no.  (I tried to use it, but did not remember the reason 
> > why it was not usable in this context while writing my previous reply.) 
> > I don't know what BUF_CHARS_MODIFF records
> 
> What BUF_CHARS_MODIFF records is documented in the doc string of
> buffer-chars-modified-tick.
> 
> > but it is for example == 2 before and after C-x i dictionary.json
> > RET.
> 
> It's a bug, plain and simple.

Should now be fixed on the master branch.