1 files changed, 6 insertions, 0 deletions

diff --git a/lisp/font-lock.el b/lisp/font-lock.el
index 052e92391af..56a4005a41c 100644
--- a/lisp/font-lock.el
+++ b/lisp/font-lock.el
@@ -1324,6 +1324,12 @@ HIGHLIGHT should be of the form MATCH-HIGHLIGHT, see `font-lock-keywords'."
           (add-text-properties start end (cddr val))
           (setq val (cadr val)))
         (cond
+         ((not val)
+          ;; If `val' is nil, don't do anything.  It is important to do it
+          ;; explicitly, because when adding nil via things like
+          ;; font-lock-append-text-property, the property is actually
+          ;; changed from <face> to (<face>) which is undesirable.  --Stef
+          nil)
          ((not override)
           ;; Cannot override existing fontification.
           (or (text-property-not-all start end 'face nil)