Re: Concerning `(letrec ((ignore)) ...)' in line 2718 of lisp/ox.el

[Zack Piper <zack@apertron.net>]

On Fri, Dec 11, 2015 at 10:27:55AM -0500, Kyle Meyer wrote:
> 
> Zack Piper <zack@apertron.net> writes:
> 
> > I (think) I have a recipe to reproduce this:
> >
> > - Emacs 25 (emacs-25 branch from Git)
> > - Org mode from latest Git (make sure that there's no ELC files from
> >   Emacs *24*, if it uses files from Emacs 24 it works fine (bug in
> >   byte compiler?)).
> >
> > ╭────[ r.el ]
> > │ (add-to-list 'load-path "~/org-mode/lisp")
> > │ (add-to-list 'load-path "~/org-mode/contrib/lisp")
> > │ (require 'org)
> > │
> > │ (find-file "~/r.org")
> > │
> > │ (org-html-export-as-html)
> > ╰────
> >
> > ╭────[ $ ]
> > │ emacs -Q -l r.el
> > ╰────
> >
> > Produces:
> >
> > ╭────
> > │ Wrong number of arguments: setq, 1
> > ╰────
> 
> I believe this because an odd number of arguments to setq now signals an
> error:
> 
>     https://lists.gnu.org/archive/html/emacs-devel/2015-11/msg02028.html
> 
> From Emacs 25 NEWS:
> 
>     ** `setq' must now be called with an even number of arguments.  The
>     earlier behavior of silently supplying a nil to the last variable when
>     there was an odd number of arguments has been eliminated.
> 
> The binding
> 
>   (letrec ((ignore)
> 
> results in letrec passing an odd number of arguments to setq:
> 
>   `(let ,(mapcar #'car binders)
>      ,@(mapcar (lambda (binder) `(setq ,@binder)) binders)
>      ,@body))
>      
> Changing (ignore) to (ignore nil) should fix it.  There are several
> other places in ox.el that have the same problem.  However, I don't know
> if letrec should handle this instead.  Nicolas?

I submitted a patch to the emacs-devel ML which fixes this (at least
for me).
Thanks very much for tracking down this issue, Kyle!


-- 
Zack Piper <zack@apertron.net> http://apertron.net