(previous-scroll-bar-mode): New variable

(set-scroll-bar-mode): Set previous-scroll-bar-mode.
(scroll-bar-mode): Use previous-scroll-bar-mode if set.

diff --git a/lisp/scroll-bar.el b/lisp/scroll-bar.el
index 69d696f7741d86e07b5e507a671d2268180c8fb1..438aa8f14dd65ffcd8249105391f478c25d328d5 100644 (file)
--- a/lisp/scroll-bar.el
+++ b/lisp/scroll-bar.el
@@ -75,6 +75,7 @@ SIDE must be the symbol `left' or `right'."
 ;;;; Helpful functions for enabling and disabling scroll bars.
 
 (defvar scroll-bar-mode)
+(defvar previous-scroll-bar-mode nil)
 
 (defvar scroll-bar-mode-explicit nil
   "Non-nil means `set-scroll-bar-mode' should really do something.
@@ -85,6 +86,9 @@ This is nil while loading `scroll-bar.el', and t afterward.")
 
 (defun set-scroll-bar-mode (value)
   "Set `scroll-bar-mode' to VALUE and put the new value into effect."
+  (if scroll-bar-mode
+      (setq previous-scroll-bar-mode scroll-bar-mode))
+
   (setq scroll-bar-mode value)
 
   (when scroll-bar-mode-explicit
@@ -137,7 +141,8 @@ turn off scroll bars; otherwise, turn on scroll bars."
                               (not scroll-bar-mode)
                             (setq flag (prefix-numeric-value flag))
                             (or (not (numberp flag)) (>= flag 0)))
-                          default-frame-scroll-bars)))
+                          (or previous-scroll-bar-mode
+                              default-frame-scroll-bars))))
 
 (defun toggle-scroll-bar (arg)
   "Toggle whether or not the selected frame has vertical scroll bars.