[at-spi2-atk] Fix issue where we would attempt to reference null objects on the child-changed removed signal.

[Mark Doffman <markdoffman src gnome org>]

commit f84b9301c551d4f828cb474fe9e55e33c08e71e6
Author: Mark Doffman <mark doffman codethink co uk>
Date:   Wed Feb 3 01:15:42 2010 -0800

    Fix issue where we would attempt to reference null objects
    on the child-changed removed signal.

 atk-adaptor/event.c  |    4 +---
 atk-adaptor/object.c |    3 +++
 2 files changed, 4 insertions(+), 3 deletions(-)
---
diff --git a/atk-adaptor/event.c b/atk-adaptor/event.c
index 9930d2c..23133cb 100644
--- a/atk-adaptor/event.c
+++ b/atk-adaptor/event.c
@@ -602,7 +602,6 @@ active_descendant_event_listener (GSignalInvocationHint * signal_hint,
   AtkObject *child;
   GSignalQuery signal_query;
   const gchar *name, *minor;
-  gchar *s;
   gint detail1;
 
   g_signal_query (signal_hint->signal_id, &signal_query);
@@ -617,7 +616,6 @@ active_descendant_event_listener (GSignalInvocationHint * signal_hint,
 
   emit_event (accessible, ITF_EVENT_OBJECT, name, "", detail1, 0,
               "(so)", child, append_object);
-  g_free (s);
   return TRUE;
 }
 
@@ -746,7 +744,7 @@ children_changed_event_listener (GSignalInvocationHint * signal_hint,
   const gchar *name, *minor;
   gint detail1, detail2 = 0;
 
-  AtkObject *accessible, *ao;
+  AtkObject *accessible, *ao=NULL;
   gpointer child;
 
   g_signal_query (signal_hint->signal_id, &signal_query);
diff --git a/atk-adaptor/object.c b/atk-adaptor/object.c
index beeada4..090ee6a 100644
--- a/atk-adaptor/object.c
+++ b/atk-adaptor/object.c
@@ -80,6 +80,9 @@ spi_object_append_reference (DBusMessageIter * iter, AtkObject * obj)
   const gchar *name;
   gchar *path;
 
+  if (!obj)
+    return spi_object_append_null_reference (iter);
+
   maybe_lease (obj);
 
   name = dbus_bus_get_unique_name (spi_global_app_data->bus);