Correctly wrap 'initproc' for slot 'tp_init'.

Author: fangerer

graalpython/com.oracle.graal.python.cext/src/object.c

@@ -195,6 +195,10 @@ static PyObject* wrap_ssizeobjargproc(ssizeobjargproc f, PyObject* a, PyObject*
 	return PyLong_FromLong(f(explicit_cast(a), PyLong_AsSsize_t(size), explicit_cast(b)));
 }
 
+static PyObject* wrap_initproc(initproc f, PyObject* a, PyObject* b, PyObject* c) {
+	return PyLong_FromLong(f(explicit_cast(a), explicit_cast(b),  explicit_cast(c)));
+}
+
 int PyType_Ready(PyTypeObject* cls) {
 #define ADD_IF_MISSING(attr, def) if (!(attr)) { attr = def; }
 #define ADD_METHOD(m) ADD_METHOD_OR_SLOT(m.ml_name, get_method_flags_cwrapper(m.ml_flags), m.ml_meth, m.ml_flags, m.ml_doc)
@@ -366,7 +370,7 @@ int PyType_Ready(PyTypeObject* cls) {
     ADD_SLOT("__next__", cls->tp_iternext, -1);
     ADD_SLOT("__get__", cls->tp_descr_get, -3);
     ADD_SLOT("__set__", cls->tp_descr_set, -3);
-    ADD_SLOT("__init__", cls->tp_init, METH_KEYWORDS | METH_VARARGS);
+    ADD_SLOT_CONV("__init__", wrap_initproc, cls->tp_init, METH_KEYWORDS | METH_VARARGS);
     ADD_SLOT_CONV("__alloc__", wrap_allocfunc, cls->tp_alloc, -2);
     ADD_SLOT("__new__", cls->tp_new, METH_KEYWORDS | METH_VARARGS);
     ADD_SLOT("__free__", cls->tp_free, -1);