(menu-bar-update-buffers): Record buffers' mod and

read-only flags, and recompute if they change.

1 files changed, 10 insertions, 2 deletions

diff --git a/lisp/menu-bar.el b/lisp/menu-bar.el
index 8b33d7d08c3..c89a356b6af 100644
--- a/lisp/menu-bar.el
+++ b/lisp/menu-bar.el
@@ -264,11 +264,19 @@ A large number or nil slows down menu responsiveness.")
 (defun menu-bar-update-buffers ()
   (let ((buffers (buffer-list))
         (frames (frame-list))
+        buffers-info
         buffers-menu frames-menu)
-    (if (and (equal buffers menu-bar-update-buffers-last-buffers)
+    (setq buffers-info
+          (mapcar (function (lambda (buffer)
+                              (list buffer (buffer-modified-p buffer)
+                                    (save-excursion
+                                      (set-buffer buffer)
+                                      buffer-read-only))))
+                  buffers))
+    (if (and (equal buffers-info menu-bar-update-buffers-last-buffers)
              (equal frames menu-bar-update-buffers-last-frames))
         nil
-      (setq menu-bar-update-buffers-last-buffers buffers)
+      (setq menu-bar-update-buffers-last-buffers buffers-info)
       (setq menu-bar-update-buffers-last-frames frames)
       ;; If requested, list only the N most recently selected buffers.
       (if (and (integerp buffers-menu-max-size)