Subject: bug#26378: 26.0.50; Hitting 'n' during ediff gives Error

From: Noam Postavsky <[email-masked]>
Date: Wed, 5 Apr 2017 17:53:51 -0400

On Wed, Apr 5, 2017 at 5:20 PM, Kaushal Modi <[email-masked]> wrote:
> Subject: [PATCH] Check that file argument is a string

>                         (mapcar (lambda (file)
> -                                 (file-name-unquote
> -                                  (or (file-local-copy file) file)))
> +                                 (when (stringp file)
> +                                   (file-name-unquote
> +                                    (or (file-local-copy file) file))))
>                                 files)))

We should probably update the comment above `ediff-exec-process' where it says:

    All elements in FILES must be strings.

This seems to be a lie, as they can also be nil.