update pickle/copy

Author: bkap123

Modules/_functoolsmodule.c

@@ -777,34 +777,11 @@ partial_repr(PyObject *self)
    operation so we define a __setstate__ that replaces all the information
    about the partial.  If we only replaced part of it someone would use
    it as a hook to do strange things.
-
-   Additionally, since frozendict does not work for pickle protocols 0 and 1,
-   __reduce_ex__ creates a temporary dict for protocols 0 and 1 and calls
-   __reduce__ for protocols 2+.
  */
 
 static PyObject *
 partial_reduce(PyObject *self, PyObject *Py_UNUSED(args))
 {
-    partialobject *pto = partialobject_CAST(self);
-    return Py_BuildValue("O(O)(OOOO)", Py_TYPE(pto), pto->fn, pto->fn,
-                         pto->args, pto->kw,
-                         pto->dict ? pto->dict : Py_None);
-}
-
-static PyObject *
-partial_reduce_ex(PyObject *self, PyObject *args)
-{
-    int64_t protocol;
-
-    if (!PyArg_ParseTuple(args, "l", &protocol)) {
-        return NULL;
-    }
-
-    if (protocol >= 2) {
-        return partial_reduce(self, NULL);
-    }
-
     partialobject *pto = partialobject_CAST(self);
     PyObject *keywords_dict = PyObject_CallOneArg((PyObject*)&PyDict_Type, pto->kw);
     PyObject *result = Py_BuildValue("O(O)(OOOO)", Py_TYPE(pto), pto->fn, pto->fn,
@@ -902,10 +879,23 @@ partial_setstate(PyObject *self, PyObject *state)
     Py_RETURN_NONE;
 }
 
+static PyObject *
+partial_copy(PyObject *self, PyObject *Py_UNUSED(args))
+{
+    partialobject *pto = partialobject_CAST(self);
+    PyTypeObject *type = Py_TYPE(pto);
+    partialobject *new_pto = (partialobject *)type->tp_alloc(type, 0);
+    new_pto->fn = Py_NewRef(pto->fn);
+    new_pto->args = Py_NewRef(pto->args);
+    new_pto->kw = Py_NewRef(pto->kw);
+    new_pto->dict = Py_XNewRef(pto->dict);
+    return (PyObject *)new_pto;
+}
+
 static PyMethodDef partial_methods[] = {
     {"__reduce__", partial_reduce, METH_NOARGS},
-    {"__reduce_ex__", partial_reduce_ex, METH_VARARGS},
     {"__setstate__", partial_setstate, METH_O},
+    {"__copy__", partial_copy, METH_NOARGS},
     {"__class_getitem__",    Py_GenericAlias,
     METH_O|METH_CLASS,       PyDoc_STR("See PEP 585")},
     {NULL,              NULL}           /* sentinel */