bug#29345: 27.0.50; Error message for cl-destructuring-bind could be improved

[Philipp Stephani <p.stephani2@gmail.com>]

Am Do., 25. Juli 2019 um 21:54 Uhr schrieb Lars Ingebrigtsen <larsi@gnus.org>:
>
> Lars Ingebrigtsen <larsi@gnus.org> writes:
>
> > Philipp Stephani <p.stephani2@gmail.com> writes:
> >
> >> $ emacs -Q -batch -l cl-lib -eval '(cl-destructuring-bind (a b) (list 1))'
> >> Wrong number of arguments: nil, 1
> >>
> >> It would be nice if the first error data item weren't nil, but
> >> e.g. `(cl-destructuring-bind (a b))` so that the error is obvious.
> >
> > What about
> >
> > Wrong number of arguments: (a b), 1
> >
> > The following patch achieves that, but since it was explicitly 'cl-none
> > before (which is the magic value that gives you nil in that error
> > message), I'm not sure whether this has any negative effects?  Probably
> > not, because there's this:
> >
> > (defvar cl--bind-block) ;Name of surrounding block, only use for `signal' data.
> >
> > Any opinions?
>
> There weren't any, so I'm applying the patch.

Thanks!