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

[Gregory Heytings]

> > Yes: that's what the "record_unwind_protect (save_restriction_restore, 
> > save_restriction_save ());" does.
>
> So save_restriction_restore will reinstate the buffer in the 
> narrowing_locks list?

Yes:

Lisp_Object
save_restriction_save (void)
{
  Lisp_Object restr = save_restriction_save_1 ();
  Lisp_Object locks = narrowing_locks_save ();
  return Fcons (restr, locks);
}

void
save_restriction_restore (Lisp_Object data)
{
  narrowing_locks_restore (XCDR (data));
  save_restriction_restore_1 (XCAR (data));
}