(menu-bar-update-buffers): If Buffers item is gone,

don't bring it back.

diff --git a/lisp/menu-bar.el b/lisp/menu-bar.el
index b6654a5dc1d8c310f02facdb715be2fcc9399991..8848dacf2c2e86b7d29b9433f357bbad1be03da0 100644 (file)
--- a/lisp/menu-bar.el
+++ b/lisp/menu-bar.el
@@ -286,100 +286,102 @@ A large number or nil slows down menu responsiveness.")
   (select-frame last-command-event))
 
 (defun menu-bar-update-buffers ()
-  (if (frame-or-buffer-changed-p)
-      (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)))
-                         (or (eq ?\ (aref (buffer-name elt) 0))
-                             (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
+  ;; If user discards the Buffers item, play along.
+  (and (lookup-key global-map [menu-bar buffer])
+       (frame-or-buffer-changed-p)
+       (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)))
+                          (or (eq ?\ (aref (buffer-name elt) 0))
+                              (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
-                               (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 frames)
-           (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))
-                               frames))))
-       (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)))))))
+                               '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 frames)
+            (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))
+                                frames))))
+        (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)