[gtk/wip/exalm/hotspot-fix-324] wayland: Fix dnd hotspot movement

[Alexander Mikhaylenko <alexm src gnome org>]

commit c67e3f37da1b092e416cab89bb0652953d5cc544
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Thu Aug 27 04:01:01 2020 +0500

    wayland: Fix dnd hotspot movement
    
    _gdk_wayland_window_offset_next_wl_buffer() moves the window relatively to
    its current position, pass it a delta instead of new position.

 gdk/wayland/gdkdnd-wayland.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gdk/wayland/gdkdnd-wayland.c b/gdk/wayland/gdkdnd-wayland.c
index ff3ed53c3d..86b159c6c5 100644
--- a/gdk/wayland/gdkdnd-wayland.c
+++ b/gdk/wayland/gdkdnd-wayland.c
@@ -374,7 +374,7 @@ gdk_wayland_drag_context_set_hotspot (GdkDragContext *context,
     return;
 
   _gdk_wayland_window_offset_next_wl_buffer (context_wayland->dnd_window,
-                                             -hot_x, -hot_y);
+                                             prev_hot_x - hot_x, prev_hot_y - hot_y);
   gdk_window_invalidate_rect (context_wayland->dnd_window, &damage_rect, FALSE);
 }