[pygobject] Unify filename to Python GI marshaling code

[Simon Feltman <sfeltman src gnome org>]

commit 2eb2a712864a1a685d19018e0860cf0da7c5c9ab
Author: Simon Feltman <sfeltman src gnome org>
Date:   Thu Mar 28 05:29:08 2013 -0700

    Unify filename to Python GI marshaling code
    
    Change _pygi_argument_to_object to use the cachers marshaler
    (_pygi_marshal_to_py_filename) directly instead of keeping a
    copy of the code.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=693405

 gi/pygi-argument.c      |   22 ++--------------------
 gi/pygi-marshal-to-py.c |    6 ++----
 2 files changed, 4 insertions(+), 24 deletions(-)
---
diff --git a/gi/pygi-argument.c b/gi/pygi-argument.c
index dd0944f..8868d4e 100644
--- a/gi/pygi-argument.c
+++ b/gi/pygi-argument.c
@@ -1534,26 +1534,8 @@ _pygi_argument_to_object (GIArgument  *arg,
         }
         case GI_TYPE_TAG_FILENAME:
         {
-            GError *error = NULL;
-            gchar *string;
-
-            if (arg->v_string == NULL) {
-                object = Py_None;
-                Py_INCREF (object);
-                break;
-            }
-
-            string = g_filename_to_utf8 (arg->v_string, -1, NULL, NULL, &error);
-            if (string == NULL) {
-                PyErr_SetString (PyExc_Exception, error->message);
-                /* TODO: Convert the error to an exception. */
-                break;
-            }
-
-            object = PYGLIB_PyUnicode_FromString (string);
-
-            g_free (string);
-
+            object = _pygi_marshal_to_py_filename (NULL, NULL, NULL,
+                                                   arg);
             break;
         }
         case GI_TYPE_TAG_ARRAY:
diff --git a/gi/pygi-marshal-to-py.c b/gi/pygi-marshal-to-py.c
index fbd2bb0..31a6add 100644
--- a/gi/pygi-marshal-to-py.c
+++ b/gi/pygi-marshal-to-py.c
@@ -306,14 +306,12 @@ _pygi_marshal_to_py_filename (PyGIInvokeState   *state,
                               PyGIArgCache      *arg_cache,
                               GIArgument        *arg)
 {
-    gchar *string;
+    gchar *string = NULL;
     PyObject *py_obj = NULL;
     GError *error = NULL;
 
     if (arg->v_string == NULL) {
-        py_obj = Py_None;
-        Py_INCREF (py_obj);
-        return py_obj;
+        Py_RETURN_NONE;
     }
 
     string = g_filename_to_utf8 (arg->v_string, -1, NULL, NULL, &error);