* lisp/newcomment.el (comment-normalize-vars): Better test validity of

comment-end-skip.

lisp/ChangeLog

+2010-09-21  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+	* newcomment.el (comment-normalize-vars): Better test validity of
+	comment-end-skip.
+
 2010-09-19  Stefan Monnier  <monnier@iro.umontreal.ca>
 
 	* emacs-lisp/float-sup.el (float-pi): New name for `pi'.

lisp/newcomment.el

@@ -318,7 +318,8 @@ the variables are properly set."
 		   "+\\)[ \t]*")))
     (unless (and comment-end-skip
 		 ;; In case comment-end has changed since last time.
-		 (string-match comment-end-skip comment-end))
+		 (string-match comment-end-skip
+                               (if (string= "" comment-end) "\n" comment-end)))
       (let ((ce (if (string= "" comment-end) "\n"
 		  (comment-string-strip comment-end t t))))
 	(set (make-local-variable 'comment-end-skip)