Give a slight better error message in mml-minibuffer-read-file

* lisp/gnus/mml.el (mml-minibuffer-read-file): Give a slightly
better error message when the user enters nothing (bug#20480).

1 files changed, 3 insertions, 1 deletions

diff --git a/lisp/gnus/mml.el b/lisp/gnus/mml.el
index df541fbcccd..19c19decedd 100644
--- a/lisp/gnus/mml.el
+++ b/lisp/gnus/mml.el
@@ -1251,9 +1251,11 @@ If not set, `default-directory' will be used."
   (let* ((completion-ignored-extensions nil)
          (file (read-file-name prompt
                                (or mml-default-directory default-directory)
-                               nil t)))
+                               "" t)))
     ;; Prevent some common errors.  This is inspired by similar code in
     ;; VM.
+    (when (zerop (length file))
+      (error "No file name entered"))
     (when (file-directory-p file)
       (error "%s is a directory, cannot attach" file))
     (unless (file-exists-p file)