if the argument of MM_pop is not NULL but an empty tuple, don't unpack it

src/DocumentTemplate/cDocumentTemplate.c

@@ -231,7 +231,7 @@ MM_pop(MM *self, PyObject *args)
   int i=1, l;
   PyObject *r;
 
-  if (args) UNLESS(PyArg_ParseTuple(args, "i", &i)) return NULL;
+  if (args && PyTuple_Size(args) != 0) UNLESS(PyArg_ParseTuple(args, "i", &i)) return NULL;
   if ((l=PyList_Size(self->data)) < 0) return NULL;
   i=l-i;
   UNLESS(r=PySequence_GetItem(self->data,l-1)) return NULL;