[at-spi2-core] Fix a crash when calling an object from a disposed application

[Mike Gorse <mgorse src gnome org>]

commit 4bc6e9e267e9164545cb6c03c9ac1cbec131613f
Author: Mike Gorse <mgorse novell com>
Date:   Thu Dec 30 06:33:56 2010 -0500

    Fix a crash when calling an object from a disposed application

 atspi/atspi-misc.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/atspi/atspi-misc.c b/atspi/atspi-misc.c
index d8feb32..23e3920 100644
--- a/atspi/atspi-misc.c
+++ b/atspi/atspi-misc.c
@@ -1005,6 +1005,13 @@ _atspi_dbus_call (gpointer obj, const char *interface, const char *method, GErro
   DBusError err;
   AtspiObject *aobj = ATSPI_OBJECT (obj);
 
+  if (!aobj->app || !aobj->app->bus)
+  {
+    g_set_error_literal (error, ATSPI_ERROR, ATSPI_ERROR_APPLICATION_GONE,
+                          _("The application no longer exists"));
+    return FALSE;
+  }
+
   va_start (args, type);
   dbus_error_init (&err);
   retval = dbind_method_call_reentrant_va (aobj->app->bus, aobj->app->bus_name,