bug#40968: 28.0.50; (apply nil)

[Eli Zaretskii]

> From: Pip Cet <pipcet@gmail.com>
> Date: Wed, 6 May 2020 17:54:23 +0000
> Cc: Stefan Kangas <stefan@marxist.se>, 40968@debbugs.gnu.org
> 
> > Can we instead identify the problematic usage and signal an error?
> 
> Yes. What we also have to do is fix the documentation, and fix the
> byte optimizer.
> 
> Here's a first suggestion. I'd particularly appreciate hints on better
> wording for the documentation.

The documentation parts of the patch look fine to me, thanks.  (The
rest also looks fine.)  Let's wait for a few days so others could
comment.