(mouse-major-mode-menu): Suppress duplicate menus.

diff --git a/lisp/mouse.el b/lisp/mouse.el
index 179670c73261124c94d3f256fd0140ef8901f203..27bf00ce26763b40e508ffb9be382a44d7eaeed4 100644 (file)
--- a/lisp/mouse.el
+++ b/lisp/mouse.el
@@ -173,11 +173,22 @@ Default to the Edit menu if the major mode doesn't define a menu."
         ;; default to the edit menu.
         (newmap (if ancestor
                     (make-sparse-keymap (concat mode-name " Mode"))
-                  menu-bar-edit-menu)))
+                  menu-bar-edit-menu))
+        uniq)
     (if ancestor
        ;; Make our menu inherit from the desired keymap which we want
        ;; to display as the menu now.
-       (set-keymap-parent newmap ancestor))
+       ;; Sometimes keymaps contain duplicate menu code, leading to
+       ;; duplicates in the popped-up menu. Avoid this by simply
+       ;; taking the first of any identically-named menus.
+       ;; http://lists.gnu.org/archive/html/emacs-devel/2007-11/msg00469.html
+       (set-keymap-parent newmap
+                          (progn
+                            (dolist (e ancestor)
+                              (unless (and (listp e)
+                                           (assoc (car e) uniq))
+                                (setq uniq (append uniq (list e)))))
+                            uniq)))
     (popup-menu newmap event prefix)))