Made font-lock-compile-keywords not compile if it looks like it already has.

diff --git a/lisp/font-lock.el b/lisp/font-lock.el
index 83ca7e049ccbc2547e57ad1aca10f18fa89bf38c..af9fca1d31313047b38adb9ba8ca8cf108204548 100644 (file)
--- a/lisp/font-lock.el
+++ b/lisp/font-lock.el
@@ -497,25 +497,27 @@ the face is also set; its value is the face name."
 \f
 ;;; Fontifying arbitrary patterns
 
-(defun font-lock-compile-keywords ()
+(defun font-lock-compile-keywords (&optional keywords)
   ;; Compile `font-lock-keywords' into the form (t KEYWORD ...) where KEYWORD
   ;; is the (MATCHER HIGHLIGHT ...) shown in the variable's doc string.
-  (setq font-lock-keywords
-   (cons t
-    (mapcar (function
-            (lambda (item)
-              (cond ((nlistp item)
-                     (list item '(0 font-lock-keyword-face)))
-                    ((numberp (cdr item))
-                     (list (car item) (list (cdr item)
-                                            'font-lock-keyword-face)))
-                    ((symbolp (cdr item))
-                     (list (car item) (list 0 (cdr item))))
-                    ((nlistp (nth 1 item))
-                     (list (car item) (cdr item)))
-                    (t
-                     item))))
-           font-lock-keywords))))
+  (let ((keywords (or keywords font-lock-keywords)))
+    (setq font-lock-keywords 
+     (if (eq (car-safe keywords) t)
+        keywords
+       (cons t
+       (mapcar
+        (function (lambda (item)
+           (cond ((nlistp item)
+                  (list item '(0 font-lock-keyword-face)))
+                 ((numberp (cdr item))
+                  (list (car item) (list (cdr item) 'font-lock-keyword-face)))
+                 ((symbolp (cdr item))
+                  (list (car item) (list 0 (cdr item))))
+                 ((nlistp (nth 1 item))
+                  (list (car item) (cdr item)))
+                 (t
+                  item))))
+        keywords))))))
 
 (defsubst font-lock-apply-highlight (highlight)
   "Apply HIGHLIGHT following a match.  See `font-lock-keywords'."