Manual forward port of 64962 - use PyObject_HashNotImplemented as a tp_hash level indicator that the default hash implementation has not been inherited
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index c139fbc..9306552 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -3810,13 +3810,15 @@
/* Hack for tp_hash and __hash__.
If after all that, tp_hash is still NULL, and __hash__ is not in
- tp_dict, set tp_dict['__hash__'] equal to None.
+ tp_dict, set tp_hash to PyObject_HashNotImplemented and
+ tp_dict['__hash__'] equal to None.
This signals that __hash__ is not inherited.
*/
if (type->tp_hash == NULL) {
if (PyDict_GetItemString(type->tp_dict, "__hash__") == NULL) {
if (PyDict_SetItemString(type->tp_dict, "__hash__", Py_None) < 0)
goto error;
+ type->tp_hash = PyObject_HashNotImplemented;
}
}
@@ -4943,9 +4945,7 @@
}
if (func == NULL) {
- PyErr_Format(PyExc_TypeError, "unhashable type: '%.200s'",
- Py_TYPE(self)->tp_name);
- return -1;
+ return PyObject_HashNotImplemented(self);
}
res = PyEval_CallObject(func, NULL);
@@ -5676,6 +5676,13 @@
sanity checks. I'll buy the first person to
point out a bug in this reasoning a beer. */
}
+ else if (descr == Py_None &&
+ strcmp(p->name, "__hash__") == 0) {
+ /* We specifically allow __hash__ to be set to None
+ to prevent inheritance of the default
+ implementation from object.__hash__ */
+ specific = PyObject_HashNotImplemented;
+ }
else {
use_generic = 1;
generic = p->function;
@@ -5889,12 +5896,21 @@
continue;
if (PyDict_GetItem(dict, p->name_strobj))
continue;
- descr = PyDescr_NewWrapper(type, p, *ptr);
- if (descr == NULL)
- return -1;
- if (PyDict_SetItem(dict, p->name_strobj, descr) < 0)
- return -1;
- Py_DECREF(descr);
+ if (*ptr == PyObject_HashNotImplemented) {
+ /* Classes may prevent the inheritance of the tp_hash
+ slot by storing PyObject_HashNotImplemented in it. Make it
+ visible as a None value for the __hash__ attribute. */
+ if (PyDict_SetItem(dict, p->name_strobj, Py_None) < 0)
+ return -1;
+ }
+ else {
+ descr = PyDescr_NewWrapper(type, p, *ptr);
+ if (descr == NULL)
+ return -1;
+ if (PyDict_SetItem(dict, p->name_strobj, descr) < 0)
+ return -1;
+ Py_DECREF(descr);
+ }
}
if (type->tp_new != NULL) {
if (add_tp_new_wrapper(type) < 0)