On Mon, Nov 6, 2017 at 2:16 PM, Noam Postavsky
<npostavs@users.sourceforge.net> wrote:
> On Mon, Nov 6, 2017 at 2:10 PM, Ken Raeburn <raeburn@permabit.com> wrote:
>
>> It appears that the emacs-26 version of defun* is happy with it (the
>> original Lisp code I posted, using &optional &key) as well, as long as I
>> provide the source, or a byte-compiled file from Emacs 25 or 26
>
> It looks like the cl-defun in newer Emacs throws away the &optional
> for you in this case.

I think we should make cl-defun reject this kind of code, to be
consistent with plain defun. See attached.