Backport of _abccoll.py by Benjamin Arangueren, issue 1383.
With some changes of my own thrown in (e.g. backport of r58107).
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 59dec4a..1a221c8 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -2590,12 +2590,6 @@
return f(self);
}
-static long
-object_hash(PyObject *self)
-{
- return _Py_HashPointer(self);
-}
-
static PyObject *
object_get_class(PyObject *self, void *closure)
{
@@ -3030,7 +3024,7 @@
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
- object_hash, /* tp_hash */
+ (hashfunc)_Py_HashPointer, /* tp_hash */
0, /* tp_call */
object_str, /* tp_str */
PyObject_GenericGetAttr, /* tp_getattro */
@@ -3236,6 +3230,33 @@
type->tp_flags |= Py_TPFLAGS_DICT_SUBCLASS;
}
+/* Map rich comparison operators to their __xx__ namesakes */
+static char *name_op[] = {
+ "__lt__",
+ "__le__",
+ "__eq__",
+ "__ne__",
+ "__gt__",
+ "__ge__",
+ "__cmp__",
+ /* These are only for overrides_hash(): */
+ "__hash__",
+};
+
+static int
+overrides_hash(PyTypeObject *type)
+{
+ int i;
+ PyObject *dict = type->tp_dict;
+
+ assert(dict != NULL);
+ for (i = 0; i < 8; i++) {
+ if (PyDict_GetItemString(dict, name_op[i]) != NULL)
+ return 1;
+ }
+ return 0;
+}
+
static void
inherit_slots(PyTypeObject *type, PyTypeObject *base)
{
@@ -3367,7 +3388,8 @@
if (type->tp_flags & base->tp_flags & Py_TPFLAGS_HAVE_RICHCOMPARE) {
if (type->tp_compare == NULL &&
type->tp_richcompare == NULL &&
- type->tp_hash == NULL)
+ type->tp_hash == NULL &&
+ !overrides_hash(type))
{
type->tp_compare = base->tp_compare;
type->tp_richcompare = base->tp_richcompare;
@@ -3548,6 +3570,18 @@
}
}
+ /* 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.
+ This signals that __hash__ is not inherited.
+ */
+ if (type->tp_hash == NULL &&
+ PyDict_GetItemString(type->tp_dict, "__hash__") == NULL &&
+ PyDict_SetItemString(type->tp_dict, "__hash__", Py_None) < 0)
+ {
+ goto error;
+ }
+
/* Some more special stuff */
base = type->tp_base;
if (base != NULL) {
@@ -4937,16 +4971,6 @@
return 0;
}
-/* Map rich comparison operators to their __xx__ namesakes */
-static char *name_op[] = {
- "__lt__",
- "__le__",
- "__eq__",
- "__ne__",
- "__gt__",
- "__ge__",
-};
-
static PyObject *
half_richcompare(PyObject *self, PyObject *other, int op)
{