bug#56682: locked narrowing

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: dgutov@yandex.ru,  56682@debbugs.gnu.org,  gregory@heytings.org
> Date: Wed, 17 Aug 2022 09:06:21 -0400
> 
> > If a package wants to count lines in a function registered with
> > jit-lock, I think it makes no sense for it to do that in Lisp.  It
> > would be much better to let such packages use the built-in
> > capabilities that we use all the time, both on the mode line and under
> > display-line-numbers mode.  There are at least two advantages to that:
> > (1) it will be at least slightly faster, sometimes more than slightly
> > (due to caching); and (2) the problem of narrowing would be seamlessly
> > resolved.
> 
> FWIW, I agree.  I don't think this information is cleanly&reliably
> exposed to ELisp

It isn't currently.  I was suggesting to do so.