* lisp/font-lock.el (font-lock-ensure): Use font-lock-specified-p (bug#39597)

diff --git a/lisp/font-lock.el b/lisp/font-lock.el
index 506c888ff640a74db8c1d0c84b20603879c020cc..e0955b74abcb1677c0a6f2ebade98de9892f58b9 100644 (file)
--- a/lisp/font-lock.el
+++ b/lisp/font-lock.el
@@ -1120,9 +1120,10 @@ locking for a mode, and is not meant to be called from lisp functions."
   "Make sure the region BEG...END has been fontified.
 If the region is not specified, it defaults to the entire accessible
 portion of the buffer."
-  (font-lock-set-defaults)
-  (funcall font-lock-ensure-function
-           (or beg (point-min)) (or end (point-max))))
+  (when (font-lock-specified-p t)
+    (font-lock-set-defaults)
+    (funcall font-lock-ensure-function
+             (or beg (point-min)) (or end (point-max)))))
 
 (defun font-lock-default-fontify-buffer ()
   "Fontify the whole buffer using `font-lock-fontify-region-function'."