(rmail-get-new-mail): Cope if display-time-string is nil.

diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index 3aa0391..fcda6eb 100644 (file)
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -720,6 +720,7 @@ argument causes us to read a file name and use that file as the inbox."
          (message "%d new message%s read"
                   new-messages (if (= 1 new-messages) "" "s"))
          (and (boundp 'display-time-string)
+              (stringp display-time-string)
               (string-match " Mail" display-time-string)
               (setq display-time-string
                     (concat