[gtk+/xi2] Allow unsetting the device window in _gtk_widget_set_device_window().

[Carlos Garnacho <carlosg src gnome org>]

commit a79003a9991d2a6bcf45599717aaa5ec8a8b3cc4
Author: Carlos Garnacho <carlos gnome org>
Date:   Sat Jan 9 13:33:00 2010 +0100

    Allow unsetting the device window in _gtk_widget_set_device_window().

 gtk/gtkwidget.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 922b9bb..dd77772 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -8682,7 +8682,7 @@ _gtk_widget_set_device_window (GtkWidget *widget,
 
   g_return_if_fail (GTK_IS_WIDGET (widget));
   g_return_if_fail (GDK_IS_DEVICE (device));
-  g_return_if_fail (GDK_IS_WINDOW (window));
+  g_return_if_fail (!window || GDK_IS_WINDOW (window));
 
   if (!GTK_WIDGET_REALIZED (widget))
     return;
@@ -8699,7 +8699,10 @@ _gtk_widget_set_device_window (GtkWidget *widget,
                                (GDestroyNotify) g_hash_table_destroy);
     }
 
-  g_hash_table_insert (device_window, device, window);
+  if (window)
+    g_hash_table_insert (device_window, device, window);
+  else
+    g_hash_table_remove (device_window, device);
 }
 
 /*