bytecomp fix for bug#14565

* lisp/emacs-lisp/bytecomp.el (byte-compile-char-before)
(byte-compile-backward-char, byte-compile-backward-word):
Handle explicit nil arguments.

lisp/ChangeLog

+2013-06-06  Glenn Morris  <rgm@gnu.org>
+
+	* emacs-lisp/bytecomp.el (byte-compile-char-before)
+	(byte-compile-backward-char, byte-compile-backward-word):
+	Handle explicit nil arguments.  (Bug#14565)
+
 2013-06-05  Alan Mackenzie  <acm@muc.de>
 	* isearch.el (isearch-allow-prefix): New user option.

lisp/emacs-lisp/bytecomp.el

@@ -3447,31 +3447,34 @@ discarding."
 (byte-defop-compiler nconc)
 
 (defun byte-compile-char-before (form)
-  (cond ((= 2 (length form))
+  (cond ((or (= 1 (length form))
+	     (and (= 2 (length form)) (not (nth 1 form))))
+	 (byte-compile-form '(char-after (1- (point)))))
+	((= 2 (length form))
 	 (byte-compile-form (list 'char-after (if (numberp (nth 1 form))
 						  (1- (nth 1 form))
 						`(1- ,(nth 1 form))))))
-	((= 1 (length form))
-	 (byte-compile-form '(char-after (1- (point)))))
 	(t (byte-compile-subr-wrong-args form "0-1"))))
 
 ;; backward-... ==> forward-... with negated argument.
 (defun byte-compile-backward-char (form)
-  (cond ((= 2 (length form))
+  (cond ((or (= 1 (length form))
+	     (and (= 2 (length form)) (not (nth 1 form))))
+	 (byte-compile-form '(forward-char -1)))
+	((= 2 (length form))
 	 (byte-compile-form (list 'forward-char (if (numberp (nth 1 form))
 						    (- (nth 1 form))
 						  `(- ,(nth 1 form))))))
-	((= 1 (length form))
-	 (byte-compile-form '(forward-char -1)))
 	(t (byte-compile-subr-wrong-args form "0-1"))))
 
 (defun byte-compile-backward-word (form)
-  (cond ((= 2 (length form))
+  (cond ((or (= 1 (length form))
+	     (and (= 2 (length form)) (not (nth 1 form))))
+	 (byte-compile-form '(forward-word -1)))
+	((= 2 (length form))
 	 (byte-compile-form (list 'forward-word (if (numberp (nth 1 form))
 						    (- (nth 1 form))
 						  `(- ,(nth 1 form))))))
-	((= 1 (length form))
-	 (byte-compile-form '(forward-word -1)))
 	(t (byte-compile-subr-wrong-args form "0-1"))))
 
 (defun byte-compile-list (form)