Handle input extension events when making a window native

It may happen when turning a client side window into a native window
that the window, or some of its children with the same native parent
have extension events enabled, and thus have an input window enabled
for the native parent which needs to change as the window is made
native.

We fix this by temporarily disabling extension events on all the affected
windows while we create the native window, and then reenable them afterwards.

This fixes: https://bugzilla.redhat.com/show_bug.cgi?id=544624

gdk/gdkwindow.c

@@ -1731,6 +1731,67 @@ gdk_window_reparent (GdkWindow *window,
     _gdk_synthesize_crossing_events_for_geometry_change (window);
 }
 
+static gboolean
+temporary_disable_extension_events (GdkWindowObject *window)
+{
+  GdkWindowObject *child;
+  GList *l;
+  gboolean res;
+
+  if (window->extension_events != 0)
+    {
+      g_object_set_data (G_OBJECT (window),
+			 "gdk-window-extension-events",
+			 GINT_TO_POINTER (window->extension_events));
+      gdk_input_set_extension_events ((GdkWindow *)window, 0,
+				      GDK_EXTENSION_EVENTS_NONE);
+    }
+  else
+    res = FALSE;
+
+  for (l = window->children; l != NULL; l = l->next)
+    {
+      child = l->data;
+
+      if (window->impl_window == child->impl_window)
+	res |= temporary_disable_extension_events (window);
+    }
+
+  return res;
+}
+
+static void
+reenable_extension_events (GdkWindowObject *window)
+{
+  GdkWindowObject *child;
+  GList *l;
+  int mask;
+
+  mask = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (window),
+					      "gdk-window-extension-events"));
+
+  if (mask != 0)
+    {
+      /* We don't have the mode here, so we pass in cursor.
+	 This works with the current code since mode is not
+	 stored except as part of the mask, and cursor doesn't
+	 change the mask. */
+      gdk_input_set_extension_events ((GdkWindow *)window, mask,
+				      GDK_EXTENSION_EVENTS_CURSOR);
+      g_object_set_data (G_OBJECT (window),
+			 "gdk-window-extension-events",
+			 NULL);
+    }
+
+  for (l = window->children; l != NULL; l = l->next)
+    {
+      child = l->data;
+
+      if (window->impl_window == child->impl_window)
+	reenable_extension_events (window);
+    }
+}
+
 /**
  * gdk_window_ensure_native:
  * @window: a #GdkWindow
@@ -1758,6 +1819,7 @@ gdk_window_ensure_native (GdkWindow *window)
   GdkWindowObject *above;
   GList listhead;
   GdkWindowImplIface *impl_iface;
+  gboolean disabled_extension_events;
 
   g_return_val_if_fail (GDK_IS_WINDOW (window), FALSE);
 
@@ -1778,6 +1840,12 @@ gdk_window_ensure_native (GdkWindow *window)
 
   /* Need to create a native window */
 
+  /* First we disable any extension events on the window or its
+     descendants to handle the native input window moving */
+  disabled_extension_events = FALSE;
+  if (impl_window->input_window)
+    disabled_extension_events = temporary_disable_extension_events (private);
+
   screen = gdk_drawable_get_screen (window);
   visual = gdk_drawable_get_visual (window);
 
@@ -1831,6 +1899,9 @@ gdk_window_ensure_native (GdkWindow *window)
   if (gdk_window_is_viewable (window))
     impl_iface->show (window, FALSE);
 
+  if (disabled_extension_events)
+    temporary_enable_extension_events (private);
+
   return TRUE;
 }