(font-lock-fontify-region): Handle comment-start-skip = nil.

1 files changed, 4 insertions, 1 deletions

diff --git a/lisp/font-lock.el b/lisp/font-lock.el
index c2a3a4dfbd8..c6f28b0739e 100644
--- a/lisp/font-lock.el
+++ b/lisp/font-lock.el
@@ -166,7 +166,10 @@ slow things down!")
       ;; Find each interesting place between here and END.
       (while (and (< (point) end)
                   (setq prev (point) prevstate state)
-                  (re-search-forward (concat "\\s\"\\|" comment-start-skip) end t)
+                  (re-search-forward (if comment-start-skip
+                                         (concat "\\s\"\\|" comment-start-skip)
+                                       "\\s\"")
+                                     end t)
                   ;; Clear out the fonts of what we skip over.
                   (progn (remove-text-properties prev (point) '(face nil)) t)
                   ;; Verify the state at that place