--- a/lisp/cmdloop.el	Tue Feb 22 22:56:02 2011 +0100
+++ b/lisp/cmdloop.el	Thu Mar 17 23:42:59 2011 +0100
@@ -146,7 +146,7 @@
     (message nil)
     (ding nil (cond ((eq etype 'undefined-keystroke-sequence)
 		     (if (and (vectorp (nth 1 error-object))
-			      (/= 0 (length (nth 1 error-object)))
+			      (not (eql 0 (length (nth 1 error-object))))
 			      (button-event-p (aref (nth 1 error-object) 0)))
 			 'undefined-click
 		       'undefined-key))
@@ -468,7 +468,7 @@
                           (single-key-description event))
                  (ding nil 'y-or-n-p)
                  (discard-input)
-                 (if (= (length pre) 0)
+                 (if (eql (length pre) 0)
                      (setq pre (gettext "Please answer y or n.  ")))))))
       yn)))
 
@@ -505,7 +505,7 @@
       ;; and-fboundp is redundant, since yes-or-no-p-dialog-box is only
       ;; bound if (featurep 'dialog). But it eliminates a compile-time
       ;; warning.
-      (and-fboundp #'yes-or-no-p-dialog-box (yes-or-no-p-dialog-box prompt))
+      (and-fboundp 'yes-or-no-p-dialog-box (yes-or-no-p-dialog-box prompt))
     (yes-or-no-p-minibuf prompt)))
 
 (defun y-or-n-p (prompt)