bpo-36379: __ipow__ must be a ternaryfunc, not a binaryfunc (GH-13546)

If a type's __ipow__ method was implemented in C, attempting to use
the *modulo* parameter would cause crashes.


https://bugs.python.org/issue36379
This commit is contained in:
Zackery Spytz 2019-05-31 03:46:36 -06:00 committed by Miss Islington (bot)
parent c7f7069e77
commit c7f803b08e
4 changed files with 36 additions and 1 deletions

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@ -184,6 +184,13 @@ class CAPITest(unittest.TestCase):
o @= m1
self.assertEqual(o, ("matmul", 42, m1))
def test_c_type_with_ipow(self):
# When the __ipow__ method of a type was implemented in C, using the
# modulo param would cause segfaults.
o = _testcapi.ipowType()
self.assertEqual(o.__ipow__(1), (1, None))
self.assertEqual(o.__ipow__(2, 2), (2, 2))
def test_return_null_without_error(self):
# Issue #23571: A function must not return NULL without setting an
# error

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@ -0,0 +1,2 @@
Fix crashes when attempting to use the *modulo* parameter when ``__ipow__``
is implemented in C.

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@ -5522,6 +5522,27 @@ static PyTypeObject matmulType = {
PyObject_Del, /* tp_free */
};
typedef struct {
PyObject_HEAD
} ipowObject;
static PyObject *
ipowType_ipow(PyObject *self, PyObject *other, PyObject *mod)
{
return Py_BuildValue("OO", other, mod);
}
static PyNumberMethods ipowType_as_number = {
.nb_inplace_power = ipowType_ipow
};
static PyTypeObject ipowType = {
PyVarObject_HEAD_INIT(NULL, 0)
.tp_name = "ipowType",
.tp_basicsize = sizeof(ipowObject),
.tp_as_number = &ipowType_as_number,
.tp_new = PyType_GenericNew
};
typedef struct {
PyObject_HEAD
@ -5947,6 +5968,11 @@ PyInit__testcapi(void)
return NULL;
Py_INCREF(&matmulType);
PyModule_AddObject(m, "matmulType", (PyObject *)&matmulType);
if (PyType_Ready(&ipowType) < 0) {
return NULL;
}
Py_INCREF(&ipowType);
PyModule_AddObject(m, "ipowType", (PyObject *)&ipowType);
if (PyType_Ready(&awaitType) < 0)
return NULL;

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@ -7016,7 +7016,7 @@ static slotdef slotdefs[] = {
IBSLOT("__imod__", nb_inplace_remainder, slot_nb_inplace_remainder,
wrap_binaryfunc, "%="),
IBSLOT("__ipow__", nb_inplace_power, slot_nb_inplace_power,
wrap_binaryfunc, "**="),
wrap_ternaryfunc, "**="),
IBSLOT("__ilshift__", nb_inplace_lshift, slot_nb_inplace_lshift,
wrap_binaryfunc, "<<="),
IBSLOT("__irshift__", nb_inplace_rshift, slot_nb_inplace_rshift,