Only show the "You can run" message if it's significantly shorter

* simple.el (execute-extended-command): Don't show the help
message if the binding isn't significantly shorter than the
M-x command the user typed (bug#19013).

lisp/ChangeLog

+2014-11-16  Lars Magne Ingebrigtsen  <larsi@gnus.org>
+
+	* simple.el (execute-extended-command): Don't show the help
+	message if the binding isn't significantly shorter than the
+	M-x command the user typed (bug#19013).
+
 2014-11-16  Ulf Jasper  <ulf.jasper@web.de>
 	* calendar/icalendar.el (icalendar--convert-tz-offset): Return

lisp/simple.el

@@ -1686,7 +1686,13 @@ invoking, give a prefix argument to `execute-extended-command'."
           (while-no-input
             (setq binding (execute-extended-command--shorter
                            (symbol-name function) typed))))
-        (when binding
+        (when (and binding
+		   (or (not (stringp binding))
+		       (> (- (length (symbol-name function)) (length binding))
+			  ;; Don't show the help message if the
+			  ;; binding isn't significantly shorter than
+			  ;; the M-x command the user typed.
+			  5)))
           (with-temp-message
               (format "You can run the command `%s' with %s"
                       function