(redisplay_window): Don't automatically select a new window

start for a contination line during mouse-click.

diff --git a/src/xdisp.c b/src/xdisp.c
index b018735c3c6e760de337c8547514a48970b8a95a..07762f5658253fa3962b1b7520def830228b67f6 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -13134,8 +13134,15 @@ redisplay_window (window, just_this_one_p)
 
       /* If first window line is a continuation line, and window start
         is inside the modified region, but the first change is before
-        current window start, we must select a new window start.*/
+        current window start, we must select a new window start.
+
+        However, if this is the result of a down-mouse event (e.g. by
+        extending the mouse-drag-overlay), we don't want to select a
+        new window start, since that would change the position under
+        the mouse, resulting in an unwanted mouse-movement rather
+        than a simple mouse-click.  */
       if (NILP (w->start_at_line_beg)
+         && NILP (do_mouse_tracking)
          && CHARPOS (startp) > BEGV)
        {
          /* Make sure beg_unchanged and end_unchanged are up to date.