[pygobject] Skip marshalling NULL output arguments in Python closures

[Simon Feltman <sfeltman src gnome org>]

commit 92f0d6ebf9b67729d8253e15fce77b0ad0375573
Author: Simon Feltman <sfeltman src gnome org>
Date:   Wed Aug 20 13:39:31 2014 -0700

    Skip marshalling NULL output arguments in Python closures
    
    Skip marshalling optional output arguments which are passed NULL
    as the memory location. This fixes fallout from bug 727004.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=735090

 gi/pygi-closure.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gi/pygi-closure.c b/gi/pygi-closure.c
index 15c6767..599503f 100644
--- a/gi/pygi-closure.c
+++ b/gi/pygi-closure.c
@@ -371,7 +371,8 @@ _pygi_closure_convert_arguments (PyGIInvokeState *state,
     for (i = 0; i < _pygi_callable_cache_args_len (cache); i++) {
         PyGIArgCache *arg_cache = g_ptr_array_index (cache->args_cache, i);
 
-        if (arg_cache->direction & PYGI_DIRECTION_FROM_PYTHON) {
+        if (arg_cache->direction & PYGI_DIRECTION_FROM_PYTHON &&
+                state->arg_values[i].v_pointer) {
             state->arg_pointers[i].v_pointer = state->arg_values[i].v_pointer;
             state->arg_values[i] = *(GIArgument *) state->arg_values[i].v_pointer;
         }