bug#44303: 28.0.50; json-pretty-print-buffer creates spurious lock file

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: simenheg@runbox.com,  44303@debbugs.gnu.org
> Date: Sun, 01 Nov 2020 13:06:00 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > But we then have this:
> >
> >   if (modification_hooks_inhibited)
> >     {
> >       signal_after_change (BEGV, size_a, ZV - BEGV);
> >       update_compositions (BEGV, ZV, CHECK_INSIDE);
> >     }
> >
> > Does this not work, or fail to unlock the file?
> 
> This does not unlock the file in the test case.

Should be fixed now on master.

I wonder whether we should actually cherry-pick this to the release
branch.  The original recipe doesn't trigger the problem there, but
that's because json-pretty-print-buffer does modify the buffer on
emacs-27.  If it didn't, we'd probably have the same problem in Emacs
27.

Thoughts?