Re: [Emacs-diffs] master 90e9cf8: * lisp/gnus/mailcap.el (mailcap-mime-data):

[Katsumi Yamaoka]

On Tue, 20 Oct 2015 10:15:09 -0400, Stefan Monnier wrote:
>>       ("pdf"
>>        (viewer . doc-view-mode)
>>        (type . "application/pdf")
>> -      (test . (eq window-system 'x)))
>> +      (test . (and (fboundp 'doc-view-mode)
>> +               (eq window-system 'x))))

> Should this be redundant?  I mean shouldn't the generic code check
> fboundp of the `viewer' anyway?

Well, do you mean we should not add non-existent viewer to
mailcap-mime-data in like this way?

(defvar mailcap-mime-data
  `(("application"
[...]
     ,@(when (fboundp 'doc-view-mode)
        '(("pdf"
           (viewer . doc-view-mode)
           (type . "application/pdf")
           (test . (eq window-system 'x)))))
[...]

It would be perhaps better than adding the fboundp check to
the test token.