[libpeas] If calling the wrapper function fails set the return value to NULL

[Garrett Regier <gregier src gnome org>]

commit 6948aa2a9ca409a1ee968ee7e64cc56845df8e55
Author: Garrett Regier <garrettregier gmail com>
Date:   Wed Mar 21 17:44:49 2012 -0700

    If calling the wrapper function fails set the return value to NULL
    
    This way for gjs, python and seed plugins if an error occurs while
    calling the function a pointer value would be set to NULL which
    should help prevent segfaults.

 libpeas/peas-extension-subclasses.c |   10 +++++++---
 1 files changed, 7 insertions(+), 3 deletions(-)
---
diff --git a/libpeas/peas-extension-subclasses.c b/libpeas/peas-extension-subclasses.c
index ffb7289..b110f98 100644
--- a/libpeas/peas-extension-subclasses.c
+++ b/libpeas/peas-extension-subclasses.c
@@ -64,6 +64,7 @@ handle_method_impl (ffi_cif  *cif,
   PeasExtensionWrapper *instance;
   GIArgument *arguments;
   GIArgument return_value;
+  gboolean success;
 
   instance = *((PeasExtensionWrapper **) args[0]);
   g_assert (PEAS_IS_EXTENSION_WRAPPER (instance));
@@ -83,9 +84,12 @@ handle_method_impl (ffi_cif  *cif,
         arguments[i].v_pointer = *((gpointer **) args[i + 1]);
     }
 
-  peas_extension_wrapper_callv (instance, impl->interface_type,
-                                impl->invoker_info, impl->method_name,
-                                arguments, &return_value);
+  success = peas_extension_wrapper_callv (instance, impl->interface_type,
+                                          impl->invoker_info, impl->method_name,
+                                          arguments, &return_value);
+
+  if (!success)
+    memset (&return_value, 0, sizeof (GIArgument));
 
   g_callable_info_load_return_type (impl->invoker_info, &return_type_info);
   if (g_type_info_get_tag (&return_type_info) != GI_TYPE_TAG_VOID)