Drew Adams <drew.adams@oracle.com> schrieb am Mo., 6. Nov. 2017 um 15:41 Uhr:
> >> We should perhaps put something about throwing error on '&option &rest'
> >> into NEWS though.
> >
> > I don't understand.  In Common Lisp it is perfectly correct
> > to use both &optional and &rest.
>
> What's rejected is (&optional &rest other-vars), whereas (&optional
> var1 &rest other-vars) is okay. Does CL accept the first form (and if
> yes, what does it mean)? I couldn't tell from the page you linked to.

CL accepts a single variable after &rest. And there must be
a variable after &optional.  (&optional foo &rest bar) is OK.

(&optional &rest foo) is not OK.
(&optional foo &rest bar toto titi) is not OK.

That should match the current behavior in Emacs Lisp now.