More attrwrapper-instead-of-dict support

Specifically, when passed to PyArg_ParseTuple when a dict argument
is asked for.

from_cpython/Python/getargs.c

@@ -619,6 +619,8 @@ int _PyArg_ParseSingle_SizeT(PyObject* obj, int arg_idx, const char* fname, cons
     return r;
 }
 
+extern PyTypeObject* attrwrapper_cls;
+
 /* Convert a non-tuple argument.  Return NULL if conversion went OK,
    or a string with a message describing the failure.  The message is
    formatted as "must be <desired type>, not <actual type>".
@@ -1279,7 +1281,7 @@ convertsimple(PyObject *arg, const char **p_format, va_list *p_va, int flags,
             type = va_arg(*p_va, PyTypeObject*);
             p = va_arg(*p_va, PyObject **);
             format++;
-            if (PyType_IsSubtype(arg->ob_type, type))
+            if (PyType_IsSubtype(arg->ob_type, type) || /* Pyston hack */ (arg->ob_type == attrwrapper_cls && type == &PyDict_Type))
                 *p = arg;
             else
                 return converterr(type->tp_name, arg, msgbuf, bufsize);

test/test_extension/api_test.c

@@ -6,8 +6,18 @@ set_size(PyObject *self, PyObject *so)
     return Py_BuildValue("i", PySet_Size(so));
 }
 
+static PyObject*
+test_attrwrapper_parse(PyObject *self, PyObject* args) {
+    PyObject* d;
+    int r = PyArg_ParseTuple(args, "O!", &PyDict_Type, &d);
+    if (!r)
+        return NULL;
+    Py_RETURN_NONE;
+}
+
 static PyMethodDef TestMethods[] = {
     {"set_size",  set_size, METH_O, "Get set size by PySet_Size." },
+    {"test_attrwrapper_parse",  test_attrwrapper_parse, METH_VARARGS, "Test PyArg_ParseTuple for attrwrappers." },
     {NULL, NULL, 0, NULL}        /* Sentinel */
 };
 

test/tests/attrwrappers.py

+# import ctypes
+# 
+# print ctypes.pythonapi.PyArg_ParseTuple(globals()
+
+import api_test
+
+api_test.test_attrwrapper_parse(globals())
+def f():
+    pass
+api_test.test_attrwrapper_parse(f.__dict__)