1 files changed, 36 insertions, 3 deletions

diff --git a/Objects/descrobject.c b/Objects/descrobject.c
index 615f499..9ffbca7 100644
--- a/Objects/descrobject.c
+++ b/Objects/descrobject.c
@@ -1313,7 +1313,7 @@ static PyMemberDef property_members[] = {
     {"fget", T_OBJECT, offsetof(propertyobject, prop_get), READONLY},
     {"fset", T_OBJECT, offsetof(propertyobject, prop_set), READONLY},
     {"fdel", T_OBJECT, offsetof(propertyobject, prop_del), READONLY},
-    {"__doc__",  T_OBJECT, offsetof(propertyobject, prop_doc), READONLY},
+    {"__doc__",  T_OBJECT, offsetof(propertyobject, prop_doc), 0},
     {0}
 };
 
@@ -1372,6 +1372,9 @@ property_dealloc(PyObject *self)
 static PyObject *
 property_descr_get(PyObject *self, PyObject *obj, PyObject *type)
 {
+    static PyObject * volatile cached_args = NULL;
+    PyObject *args;
+    PyObject *ret;
     propertyobject *gs = (propertyobject *)self;
 
     if (obj == NULL || obj == Py_None) {
@@ -1382,7 +1385,29 @@ property_descr_get(PyObject *self, PyObject *obj, PyObject *type)
         PyErr_SetString(PyExc_AttributeError, "unreadable attribute");
         return NULL;
     }
-    return PyObject_CallFunctionObjArgs(gs->prop_get, obj, NULL);
+    args = cached_args;
+    if (!args || Py_REFCNT(args) != 1) {
+        Py_CLEAR(cached_args);
+        if (!(cached_args = args = PyTuple_New(1)))
+            return NULL;
+    }
+    Py_INCREF(args);
+    assert (Py_REFCNT(args) == 2);
+    Py_INCREF(obj);
+    PyTuple_SET_ITEM(args, 0, obj);
+    ret = PyObject_Call(gs->prop_get, args, NULL);
+    if (args == cached_args) {
+        if (Py_REFCNT(args) == 2) {
+            obj = PyTuple_GET_ITEM(args, 0);
+            PyTuple_SET_ITEM(args, 0, NULL);
+            Py_XDECREF(obj);
+        }
+        else {
+            Py_CLEAR(cached_args);
+        }
+    }
+    Py_DECREF(args);
+    return ret;
 }
 
 static int
@@ -1584,6 +1609,14 @@ property_traverse(PyObject *self, visitproc visit, void *arg)
     return 0;
 }
 
+static int
+property_clear(PyObject *self)
+{
+    propertyobject *pp = (propertyobject *)self;
+    Py_CLEAR(pp->prop_doc);
+    return 0;
+}
+
 PyTypeObject PyProperty_Type = {
     PyVarObject_HEAD_INIT(&PyType_Type, 0)
     "property",                                 /* tp_name */
@@ -1609,7 +1642,7 @@ PyTypeObject PyProperty_Type = {
         Py_TPFLAGS_BASETYPE,                    /* tp_flags */
     property_doc,                               /* tp_doc */
     property_traverse,                          /* tp_traverse */
-    0,                                          /* tp_clear */
+    (inquiry)property_clear,                    /* tp_clear */
     0,                                          /* tp_richcompare */
     0,                                          /* tp_weaklistoffset */
     0,                                          /* tp_iter */