gnus-art.el (gnus-mime-view-part-as-type): Make it work when being called interactively.

lisp/gnus/ChangeLog

 2010-10-06  Katsumi Yamaoka  <yamaoka@jpl.org>
+	* gnus-art.el (gnus-mime-view-part-as-type): Make it work when being
+	called interactively.
+
 	* gnus-util.el (gnus-remove-if): Allow hash table.
 	(gnus-remove-if-not): New function.

lisp/gnus/gnus-art.el

@@ -5139,7 +5139,9 @@ available media-types."
 	  (let ((default (gnus-mime-view-part-as-type-internal)))
 	    (gnus-completing-read
 	     "View as MIME type"
-	     (gnus-remove-if-not pred (mailcap-mime-types))
+	     (if pred
+		 (gnus-remove-if-not pred (mailcap-mime-types))
+	       (mailcap-mime-types))
 	     nil nil nil
 	     (car default)))))
   (gnus-article-check-buffer)