--- old/gtk+-2.24.23/gdk/quartz/GdkQuartzWindow.c	2013-10-16 11:29:55.000000000 -0400
+++ new/gtk+-2.24.23/gdk/quartz/GdkQuartzWindow.c	2015-07-20 15:05:40.000000000 -0400
@@ -625,6 +625,41 @@
   event.dnd.send_event = FALSE;
   event.dnd.context = _gdk_quartz_drag_source_context;
 
+  /* Check to see if the coordinates are inside a known GdkWindow */
+
+  GdkScreen* screen = gdk_window_get_screen (event.dnd.window);
+
+  if (screen) 
+    {
+       GList* windows, *list;
+       gint gx, gy;
+       
+       event.dnd.context->dest_window = NULL;
+
+       windows = gdk_screen_get_toplevel_windows (screen);
+       _gdk_quartz_window_nspoint_to_gdk_xy (aPoint, &gx, &gy);
+       
+       for (list = windows; list; list = list->next) 
+         {
+            GdkWindow* win = (GdkWindow*) list->data;
+            gint wx, wy;
+            gint ww, wh;
+            
+            gdk_window_get_root_origin (win, &wx, &wy);
+            ww = gdk_window_get_width (win);
+            wh = gdk_window_get_height (win);
+            
+            if (gx > wx && 
+                gy > wy &&
+                gx <= wx + ww && 
+                gy <= wy + wh) 
+              {
+                 /* found a toplevel GdkWindow at the drop position */
+                 event.dnd.context->dest_window = win;
+              }
+         }
+    }
+
   (*_gdk_event_func) (&event, _gdk_event_data);
 
   g_object_unref (event.dnd.window);