Fix handling hscroll during drag-and-drop

* lisp/x-dnd.el (x-dnd-hscroll-flags): Delete function.
(x-dnd-get-modifiers, x-dnd-wheel-modifier-type): New functions.
(x-dnd-mwheel-scroll): Use that to determine hscroll instead.
* src/window.c (set_window_hscroll): Mark window as needing
redisplay if the hscroll really changed.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/window.c b/src/window.c
index 8f889585582..3cd2f98a850 100644
--- a/src/window.c
+++ b/src/window.c
@@ -1275,7 +1275,10 @@ set_window_hscroll (struct window *w, EMACS_INT hscroll)
 
   /* Prevent redisplay shortcuts when changing the hscroll.  */
   if (w->hscroll != new_hscroll)
-    XBUFFER (w->contents)->prevent_redisplay_optimizations_p = true;
+    {
+      XBUFFER (w->contents)->prevent_redisplay_optimizations_p = true;
+      wset_redisplay (w);
+    }
 
   w->hscroll = new_hscroll;
   w->suspend_auto_hscroll = true;