pythongh-119011: Return an empty tuple on type_get_type_params as special case for PyType_Type

Author: mdkcore0

Misc/NEWS.d/next/Core and Builtins/2024-05-21-11-51-54.gh-issue-119011.Ja5dwc.rst

@@ -0,0 +1,2 @@
+This fixes an issue with ``functools.update_wrapper`` where it was not
+returning a tuple for ``__type_params__`` as expected.

Objects/typeobject.c

@@ -1743,7 +1743,7 @@ static PyObject *
 type_get_type_params(PyTypeObject *type, void *context)
 {
     PyObject *params;
-    if (PyDict_GetItemRef(lookup_tp_dict(type), &_Py_ID(__type_params__), &params) == 0) {
+    if (type == &PyType_Type || PyDict_GetItemRef(lookup_tp_dict(type), &_Py_ID(__type_params__), &params) == 0) {
         return PyTuple_New(0);
     }
     return params;