[pygi] Return an empty list when a NULL GList and GSList is returned

[Tomeu Vizoso <tomeuv src gnome org>]

commit 4b369f8aca980fc6a582094d6648f40fe4af5e9f
Author: John (J5) Palmieri <johnp redhat com>
Date:   Sat May 22 13:21:30 2010 +0200

    Return an empty list when a NULL GList and GSList is returned
    
    * In GTK a GList * and GSList set to NULL is equivilant to empty list. All
      GTK list methods can take a NULL and treat it as an empty list. e.g.
      g_list_length(NULL) returns 0
    * PyGtk consitently returns empty list when a NULL is returned for  GList or
      GSList return
    * Many PyGtk apps do this:
        for i in range(len(obj.get_list())):
            ...
    * If we were to continue to return None, they would have to add a check
      which is needlessly verbose and isn't very "pythonic"
    
    https://bugzilla.gnome.org/show_bug.cgi?id=619232

 gi/pygi-argument.c       |    6 ------
 tests/test_everything.py |    4 ++--
 2 files changed, 2 insertions(+), 8 deletions(-)
---
diff --git a/gi/pygi-argument.c b/gi/pygi-argument.c
index 930df31..6461980 100644
--- a/gi/pygi-argument.c
+++ b/gi/pygi-argument.c
@@ -1563,12 +1563,6 @@ _pygi_argument_to_object (GArgument  *arg,
             GITransfer item_transfer;
             gsize i;
 
-            if (arg->v_pointer == NULL) {
-                object = Py_None;
-                Py_INCREF(object);
-                break;
-            }
-
             list = arg->v_pointer;
             length = g_slist_length(list);
 
diff --git a/tests/test_everything.py b/tests/test_everything.py
index ab4bdc9..5953dd1 100644
--- a/tests/test_everything.py
+++ b/tests/test_everything.py
@@ -65,8 +65,8 @@ class TestNullableArgs(unittest.TestCase):
         self.assertEqual(None, Everything.test_ghash_null_out())
 
     def test_out_nullable_list(self):
-        self.assertEqual(None, Everything.test_gslist_null_out())
-        self.assertEqual(None, Everything.test_glist_null_out())
+        self.assertEqual([], Everything.test_gslist_null_out())
+        self.assertEqual([], Everything.test_glist_null_out())
 
     def test_out_nullable_array(self):
         self.assertEqual(None, Everything.test_array_int_null_out())