From 2309498595cb5a69547ad87a66b4574971684ec3 Mon Sep 17 00:00:00 2001 From: Guido van Rossum Date: Mon, 10 Jun 2002 14:30:43 +0000 Subject: Three's a charm: yet another fix for SF bug 551412. Thinking again about the test case, slot_nb_power gets called on behalf of its second argument, but with a non-None modulus it wouldn't check this, and believes it is called on behalf of its first argument. Fix this properly, and get rid of the code in _PyType_Lookup() that tries to call _PyType_Ready(). But do leave a check for a NULL tp_mro there, because this can still legitimately occur. I'll fix this in 2.2.x too. --- Objects/typeobject.c | 36 +++++++++++++++++------------------- 1 file changed, 17 insertions(+), 19 deletions(-) diff --git a/Objects/typeobject.c b/Objects/typeobject.c index cb2c791..07de6dc 100644 --- a/Objects/typeobject.c +++ b/Objects/typeobject.c @@ -1309,22 +1309,13 @@ _PyType_Lookup(PyTypeObject *type, PyObject *name) /* Look in tp_dict of types in MRO */ mro = type->tp_mro; - if (mro == NULL) { - if (PyType_Ready(type) < 0) { - /* It's not ideal to clear the error condition, - but this function is documented as not setting - an exception, and I don't want to change that. - When PyType_Ready() can't proceed, it won't - set the "ready" flag, so future attempts to ready - the same type will call it again -- hopefully - in a context that propagates the exception out. - */ - PyErr_Clear(); - return NULL; - } - mro = type->tp_mro; - assert(mro != NULL); - } + + /* If mro is NULL, the type is either not yet initialized + by PyType_Ready(), or already cleared by type_clear(). + Either way the safest thing to do is to return NULL. */ + if (mro == NULL) + return NULL; + assert(PyTuple_Check(mro)); n = PyTuple_GET_SIZE(mro); for (i = 0; i < n; i++) { @@ -3099,9 +3090,16 @@ slot_nb_power(PyObject *self, PyObject *other, PyObject *modulus) if (modulus == Py_None) return slot_nb_power_binary(self, other); - /* Three-arg power doesn't use __rpow__ */ - return call_method(self, "__pow__", &pow_str, - "(OO)", other, modulus); + /* Three-arg power doesn't use __rpow__. But ternary_op + can call this when the second argument's type uses + slot_nb_power, so check before calling self.__pow__. */ + if (self->ob_type->tp_as_number != NULL && + self->ob_type->tp_as_number->nb_power == slot_nb_power) { + return call_method(self, "__pow__", &pow_str, + "(OO)", other, modulus); + } + Py_INCREF(Py_NotImplemented); + return Py_NotImplemented; } SLOT0(slot_nb_negative, "__neg__") -- cgit v0.12