[gtk+] gdkwindow: Specify some invariants for cursors

[Jasper St. Pierre <jstpierre src gnome org>]

commit 52e3b8838240c01b416783372703bf4ad9045c1d
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Mon Oct 27 21:18:15 2014 -0700

    gdkwindow: Specify some invariants for cursors
    
    Cursors should not be on a different display than their window /
    device, as that would break Wayland.

 gdk/gdkwindow.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index c0186aa..1f05aff 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -6015,6 +6015,9 @@ gdk_window_set_cursor_internal (GdkWindow *window,
   if (GDK_WINDOW_DESTROYED (window))
     return;
 
+  g_assert (gdk_window_get_display (window) == gdk_device_get_display (device));
+  g_assert (!cursor || gdk_window_get_display (window) == gdk_cursor_get_display (cursor));
+
   if (window->window_type == GDK_WINDOW_ROOT ||
       window->window_type == GDK_WINDOW_FOREIGN)
     GDK_WINDOW_IMPL_GET_CLASS (window->impl)->set_device_cursor (window, device, cursor);