(scroll-bar-drag-1): Set point-before-scroll properly.

(scroll-bar-scroll-down, scroll-bar-scroll-up): Likewise.

1 files changed, 27 insertions, 16 deletions

diff --git a/lisp/scroll-bar.el b/lisp/scroll-bar.el
index 25b0a80d89f..ad1e07abcdb 100644
--- a/lisp/scroll-bar.el
+++ b/lisp/scroll-bar.el
@@ -133,17 +133,20 @@ EVENT should be a scroll bar click or drag event."
 If you click outside the slider, the window scrolls to bring the slider there."
   (interactive "e")
   (let* (done)
+    (or point-before-scroll
+        (setq point-before-scroll (point)))
     (scroll-bar-drag-1 event)
-    (track-mouse
-      (while (not done)
-        (setq event (read-event))
-        (if (eq (car-safe event) 'mouse-movement)
-            (setq event (read-event)))
-        (cond ((eq (car-safe event) 'scroll-bar-movement)
-               (scroll-bar-drag-1 event))
-              (t
-               ;; Exit when we get the drag event; ignore that event.
-               (setq done t)))))))
+    (let (point-before-scroll)
+      (track-mouse
+        (while (not done)
+          (setq event (read-event))
+          (if (eq (car-safe event) 'mouse-movement)
+              (setq event (read-event)))
+          (cond ((eq (car-safe event) 'scroll-bar-movement)
+                 (scroll-bar-drag-1 event))
+                (t
+                 ;; Exit when we get the drag event; ignore that event.
+                 (setq done t))))))))
 
 (defun scroll-bar-scroll-down (event)
   "Scroll the window's top line down to the location of the scroll bar click.
@@ -155,9 +158,13 @@ EVENT should be a scroll bar click."
           (let* ((end-position (event-end event))
                  (window (nth 0 end-position))
                  (portion-whole (nth 2 end-position)))
-            (select-window window)
-            (scroll-down
-             (scroll-bar-scale portion-whole (1- (window-height))))))
+            (let (point-before-scroll)
+              (select-window window))
+            (or point-before-scroll
+                (setq point-before-scroll (point)))
+            (let (point-before-scroll)
+              (scroll-down
+               (scroll-bar-scale portion-whole (1- (window-height)))))))
       (select-window old-selected-window))))
 
 (defun scroll-bar-scroll-up (event)
@@ -170,9 +177,13 @@ EVENT should be a scroll bar click."
           (let* ((end-position (event-end event))
                  (window (nth 0 end-position))
                  (portion-whole (nth 2 end-position)))
-            (select-window window)
-            (scroll-up
-             (scroll-bar-scale portion-whole (1- (window-height))))))
+            (let (point-before-scroll)
+              (select-window window))
+            (or point-before-scroll
+                (setq point-before-scroll (point)))
+            (let (point-before-scroll)
+              (scroll-up
+               (scroll-bar-scale portion-whole (1- (window-height)))))))
       (select-window old-selected-window))))