bug#26624: 26.0.50; Generalized variable `buffer-local-value' does't restore local flag

[Eli Zaretskii]

> From: Noam Postavsky <npostavs@users.sourceforge.net>
> Date: Sun, 24 Sep 2017 13:43:20 -0400
> Cc: Michael Heerdegen <michael_heerdegen@web.de>, 26624@debbugs.gnu.org
> 
> Philipp Stephani <p.stephani2@gmail.com> writes:
> 
> > Noam Postavsky <npostavs@users.sourceforge.net> schrieb am So., 24.
> > Sep. 2017 um 17:44 Uhr:
> >
> >     Philipp Stephani <p.stephani2@gmail.com> writes:
> >    
> >     > * lisp/emacs-lisp/gv.el (buffer-local-value): Remove.
> >    
> >     Is it possible to just give an obsolete warning first?
> >
> >
> > I don't think it's possible in the sense of `make-obsolete' because
> > the expander is not a named function.
> > It would be possible to use `display-warning' within the body of the
> > setter, but that would only annoy users.
> > If necessary, we might add additional code to the `setf' macro to
> > warn about this form in particular during byte compilation.
> 
> IMO, a compilation warning would be appropriate.

I agree.  Removing some feature without due warning is not something
we should do, except in very rare cases (which this one isn't).