> From: Philipp Stephani <p.stephani2@gmail.com>
> Date: Thu, 10 Nov 2016 12:58:39 +0000
>
> Philipp Stephani <p.stephani2@gmail.com> schrieb am Mi., 9. Nov. 2016 um 22:19 Uhr:
>
>  For example:
>
>  (funcall (lambda (&optional &rest &rest &optional x) (list x)) 'a)
>  => ((a))
>
>  Obviously here the &rest keyword "wins", but I think that's overly
>  confusing. Such an argument list is most likely a programmer mistake,
>  and should signal an error to make the programmer aware of the mistake.
>
> Here's a patch that detects such argument lists.

Thanks, please push to master.