[2.7] closes bpo-31608: Fix a crash in methods of a subclass of _collections.deque with a bad __new__(). (GH-9179)
diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
index 9364aba..3ca3930 100644
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -859,11 +859,20 @@
static PyObject *
deque_copy(PyObject *deque)
{
+ PyObject *result;
if (((dequeobject *)deque)->maxlen == -1)
- return PyObject_CallFunction((PyObject *)(Py_TYPE(deque)), "O", deque, NULL);
+ result = PyObject_CallFunction((PyObject *)(Py_TYPE(deque)), "O", deque, NULL);
else
- return PyObject_CallFunction((PyObject *)(Py_TYPE(deque)), "Oi",
+ result = PyObject_CallFunction((PyObject *)(Py_TYPE(deque)), "Oi",
deque, ((dequeobject *)deque)->maxlen, NULL);
+ if (result != NULL && !PyObject_TypeCheck(result, &deque_type)) {
+ PyErr_Format(PyExc_TypeError,
+ "%.200s() must return a deque, not %.200s",
+ Py_TYPE(deque)->tp_name, Py_TYPE(result)->tp_name);
+ Py_DECREF(result);
+ return NULL;
+ }
+ return result;
}
PyDoc_STRVAR(copy_doc, "Return a shallow copy of a deque.");