Don't call menu-bar-mode here.

(menu-bar-update-buffers): Check whether frames ad
buffers have actually changed; if not, do nothing.

diff --git a/lisp/menu-bar.el b/lisp/menu-bar.el
index 8f8e0ef5bf1d5d3847c389bcb38c262b87234116..e4367af2640ec6535221e72d09eef52ad729357b 100644 (file)
--- a/lisp/menu-bar.el
+++ b/lisp/menu-bar.el
@@ -254,99 +254,108 @@ A large number or nil slows down menu responsiveness.")
   (raise-frame last-command-event)
   (select-frame last-command-event))
 
+(defvar menu-bar-update-buffers-last-buffers nil)
+(defvar menu-bar-update-buffers-last-frames nil)
+
 (defun menu-bar-update-buffers ()
   (let ((buffers (buffer-list))
+       (frames (frame-list))
        buffers-menu frames-menu)
-    ;; If requested, list only the N most recently selected buffers.
-    (if (and (integerp buffers-menu-max-size)
-            (> buffers-menu-max-size 1))
-       (if (> (length buffers) buffers-menu-max-size)
-           (setcdr (nthcdr buffers-menu-max-size buffers) nil)))
-
-    ;; Make the menu of buffers proper.
-    (setq buffers-menu
-         (cons "Select Buffer"
-               (let ((tail buffers)
-                     (maxbuf 0)
-                     (maxlen 0)
-                     alist
-                     head)
-                 (while tail
-                   (or (eq ?\ (aref (buffer-name (car tail)) 0))
-                       (setq maxbuf
-                             (max maxbuf
-                                  (length (buffer-name (car tail))))))
-                   (setq tail (cdr tail)))
-                 (setq tail buffers)
-                 (while tail
-                   (let ((elt (car tail)))
-                     (if (not (string-match "^ "
-                                            (buffer-name elt)))
-                         (setq alist (cons
+    (if (and (equal buffers 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-frames frames)
+      ;; If requested, list only the N most recently selected buffers.
+      (if (and (integerp buffers-menu-max-size)
+              (> buffers-menu-max-size 1))
+         (if (> (length buffers) buffers-menu-max-size)
+             (setcdr (nthcdr buffers-menu-max-size buffers) nil)))
+
+      ;; Make the menu of buffers proper.
+      (setq buffers-menu
+           (cons "Select Buffer"
+                 (let ((tail buffers)
+                       (maxbuf 0)
+                       (maxlen 0)
+                       alist
+                       head)
+                   (while tail
+                     (or (eq ?\ (aref (buffer-name (car tail)) 0))
+                         (setq maxbuf
+                               (max maxbuf
+                                    (length (buffer-name (car tail))))))
+                     (setq tail (cdr tail)))
+                   (setq tail buffers)
+                   (while tail
+                     (let ((elt (car tail)))
+                       (if (not (string-match "^ "
+                                              (buffer-name elt)))
+                           (setq alist (cons
+                                        (cons
+                                         (format
+                                          (format "%%%ds  %%s%%s  %%s"
+                                                  maxbuf)
+                                          (buffer-name elt)
+                                          (if (buffer-modified-p elt)
+                                              "*" " ")
+                                          (save-excursion
+                                            (set-buffer elt)
+                                            (if buffer-read-only "%" " "))
+                                          (or (buffer-file-name elt)
+                                              (save-excursion
+                                                (set-buffer elt)
+                                                list-buffers-directory)
+                                              ""))
+                                         elt)
+                                        alist)))
+                       (and alist (> (length (car (car alist))) maxlen)
+                            (setq maxlen (length (car (car alist))))))
+                     (setq tail (cdr tail)))
+                   (setq alist (nreverse alist))
+                   (nconc (mapcar '(lambda (pair)
+                                     ;; This is somewhat risque, to use
+                                     ;; the buffer name itself as the event type
+                                     ;; to define, but it works.
+                                     ;; It would not work to use the buffer
+                                     ;; since a buffer as an event has its
+                                     ;; own meaning.
+                                     (nconc (list (buffer-name (cdr pair))
+                                                  (car pair)
+                                                  (cons nil nil))
+                                            'menu-bar-select-buffer))
+                                  alist)
+                          (list (cons 'list-buffers
                                       (cons
-                                       (format
-                                        (format "%%%ds  %%s%%s  %%s"
-                                                maxbuf)
-                                        (buffer-name elt)
-                                        (if (buffer-modified-p elt)
-                                            "*" " ")
-                                        (save-excursion
-                                          (set-buffer elt)
-                                          (if buffer-read-only "%" " "))
-                                        (or (buffer-file-name elt)
-                                            (save-excursion
-                                              (set-buffer elt)
-                                              list-buffers-directory)
-                                            ""))
-                                       elt)
-                                      alist)))
-                     (and alist (> (length (car (car alist))) maxlen)
-                          (setq maxlen (length (car (car alist))))))
-                   (setq tail (cdr tail)))
-                 (setq alist (nreverse alist))
-                 (nconc (mapcar '(lambda (pair)
-                                   ;; This is somewhat risque, to use
-                                   ;; the buffer name itself as the event type
-                                   ;; to define, but it works.
-                                   ;; It would not work to use the buffer
-                                   ;; since a buffer as an event has its
-                                   ;; own meaning.
-                                   (nconc (list (buffer-name (cdr pair))
-                                                (car pair)
-                                                (cons nil nil))
-                                          'menu-bar-select-buffer))
-                                alist)
-                        (list (cons 'list-buffers
-                                    (cons
-                                     (concat (make-string (max (- (/ maxlen
-                                                                     2)
-                                                                  8)
-                                                               0) ?\ )
-                                             "List All Buffers")
-                                     'list-buffers)))))))
-
-    ;; Make a Frames menu if we have more than one frame.
-    (if (cdr (frame-list))
-       (setq frames-menu
-             (cons "Select Frame"
-                   (mapcar '(lambda (frame)
-                              (nconc (list frame
-                                           (cdr (assq 'name
-                                                      (frame-parameters frame)))
-                                           (cons nil nil))
-                                     'menu-bar-select-frame))
-                           (frame-list)))))
-    (if buffers-menu
-       (setq buffers-menu (cons 'keymap buffers-menu)))
-    (if frames-menu
-       (setq frames-menu (cons 'keymap frames-menu)))
-    (define-key global-map [menu-bar buffer]
-      (cons "Buffers"
-           (if (and buffers-menu frames-menu)
-               (list 'keymap "Buffers and Frames"
-                     (cons 'buffers (cons "Buffers" buffers-menu))
-                     (cons 'frames (cons "Frames" frames-menu)))
-             (or buffers-menu frames-menu 'undefined))))))
+                                       (concat (make-string (max (- (/ maxlen
+                                                                       2)
+                                                                    8)
+                                                                 0) ?\ )
+                                               "List All Buffers")
+                                       'list-buffers)))))))
+
+      ;; Make a Frames menu if we have more than one frame.
+      (if (cdr frame)
+         (setq frames-menu
+               (cons "Select Frame"
+                     (mapcar '(lambda (frame)
+                                (nconc (list frame
+                                             (cdr (assq 'name
+                                                        (frame-parameters frame)))
+                                             (cons nil nil))
+                                       'menu-bar-select-frame))
+                             frame))))
+      (if buffers-menu
+         (setq buffers-menu (cons 'keymap buffers-menu)))
+      (if frames-menu
+         (setq frames-menu (cons 'keymap frames-menu)))
+      (define-key global-map [menu-bar buffer]
+       (cons "Buffers"
+             (if (and buffers-menu frames-menu)
+                 (list 'keymap "Buffers and Frames"
+                       (cons 'buffers (cons "Buffers" buffers-menu))
+                       (cons 'frames (cons "Frames" frames-menu)))
+               (or buffers-menu frames-menu 'undefined)))))))
 
 (add-hook 'menu-bar-update-hook 'menu-bar-update-buffers)
 
@@ -400,10 +409,6 @@ turn off menu bars; otherwise, turn on menu bars."
                                            (if menu-bar-mode 1 0))))
        (setq frames (cdr frames))))))
 
-;; Make frames created from now on have a menu bar.
-(if window-system
-    (menu-bar-mode t))
-
 (provide 'menu-bar)
 
 ;;; menu-bar.el ends here