(add-minor-mode): New function.

lisp/subr.el

@@ -1485,4 +1485,19 @@ If DIR-FLAG is non-nil, create a new empty directory instead of a file."
       nil)
     file))
 
+
+(defun add-minor-mode (symbol name map)
+  "Register a new minor mode.
+SYMBOL is the name of a buffer-local variable that is toggled on
+or off to say whether the minor mode is active or not.  NAME is the
+string that will appear in the mode line when the minor mode is
+active.  MAP is the keymap for the minor mode."
+  (make-local-variable symbol)
+  (setq symbol t)
+  (unless (assq symbol minor-mode-alist)
+    (add-to-list 'minor-mode-alist (list symbol name)))
+  (unless (assq symbol minor-mode-map-alist)
+    (add-to-list 'minor-mode-map-alist (cons symbol map))))
+
+
 ;;; subr.el ends here