Stefan Monnier <monnier@iro.umontreal.ca> schrieb am Di., 13. Dez. 2016 um
14:41 Uhr:

> >     * lisp/emacs-lisp/advice.el (ad-preactivate-advice):
> >     Avoid setting the function definition of nil.
> >     This was happening during bootstrap of org-compat.el,
> >     apparently due to eager macro expansion of code behind
> >     a (featurep 'xemacs) test.
>
> Really, I think this business of "disallow fset of nil" is a big waste
> of time and will just lead to more pain than gain.
>
> There are umpteen different ways for the user to shoot himself in the
> foot.  This one is not even fatal.
>
> Should we also disallow (fset 'car nil)?  How 'bout (fset 'car #'cdr)?
>
>
Yes, fset for most primitives should be forbidden.