bug#73881: 31.0.50; Unexpected warnings about recursive occurrences of obsolete functions

[Eli Zaretskii <eliz@gnu.org>]

> From: Eshel Yaron <me@eshelyaron.com>
> Cc: 73881@debbugs.gnu.org
> Date: Sat, 19 Oct 2024 20:11:08 +0200
> 
> >> In allout-old-expose-topic:
> >> allout.el:5092:29: Warning: ‘allout-old-expose-topic’ is an obsolete function
> >>     (as of 28.1); use ‘allout-expose-topic’ instead.
> >> allout.el:5097:44: Warning: ‘allout-old-expose-topic’ is an obsolete function
> >>     (as of 28.1); use ‘allout-expose-topic’ instead.
> >> allout.el:5106:8: Warning: ‘allout-old-expose-topic’ is an obsolete function
> >>     (as of 28.1); use ‘allout-expose-topic’ instead.
> >> --8<---------------cut here---------------end--------------->8---
> >> 
> >> These warnings are unhelpful since these are recursive calls within the
> >> definition of the obsolete function itself.  They need not be replaced
> >> with another function as the warnings suggest.  Ideally, recursive calls
> >> to obsolete functions should not produce such warnings.
> >
> > From where I stand, this could be closed as wontfix, unless someone
> > sees an easy fix.  I don't see any harm from emitting these warnings
> > in this scenario.  The warnings are correct.
> 
> All right, FWIW I find them more distracting then helpful: if I'm
> declaring a function as obsolete, that means it's going to stay around
> for at least a short while, with its recursive calls, which I have no
> interest in adapting.  So these warnings do not tell me anything useful.
> 
> As for an easy fix, maybe something like this?
> 
> diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
> index 29e7882c851..edb8160a250 100644
> --- a/lisp/emacs-lisp/bytecomp.el
> +++ b/lisp/emacs-lisp/bytecomp.el
> @@ -1533,6 +1533,7 @@ byte-compile-arglist-signature-string
>  
>  (defun byte-compile-function-warn (f nargs def)
>    (when (and (get f 'byte-obsolete-info)
> +             (not (eq f byte-compile-current-form)) ; Recursive call.
>               (not (memq f byte-compile-not-obsolete-funcs)))
>      (byte-compile-warn-obsolete f "function"))

Thanks, let's see what others think about this.