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author | Oren Milman <orenmn@gmail.com> | 2018-09-11 21:46:55 +0300 |
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committer | Benjamin Peterson <benjamin@python.org> | 2018-09-11 11:48:35 -0700 |
commit | a7c1f94b4b054ed69e873cbe3f3e528ac7cf3e5f (patch) | |
tree | e26233e193cdac999426a849c3b75a83e52bf28a | |
parent | 889f080a4d5cdb1cfb901b953f4b89f3ea806bbe (diff) | |
download | cpython-git-backport-24bd50b-3.6.tar.gz |
[3.6] closes bpo-31608: Fix a crash in methods of a subclass of _collections.deque with a bad __new__(). (GH-3788).backport-24bd50b-3.6
(cherry picked from commit 24bd50bdcc97d65130c07d6cd26085fd06c3e972)
Co-authored-by: Oren Milman <orenmn@gmail.com>
-rw-r--r-- | Lib/test/test_deque.py | 15 | ||||
-rw-r--r-- | Misc/NEWS.d/next/Library/2017-10-29-10-37-55.bpo-31608.wkp8Nw.rst | 2 | ||||
-rw-r--r-- | Modules/_collectionsmodule.c | 16 |
3 files changed, 30 insertions, 3 deletions
diff --git a/Lib/test/test_deque.py b/Lib/test/test_deque.py index ce517b51d5..ed9ea0251a 100644 --- a/Lib/test/test_deque.py +++ b/Lib/test/test_deque.py @@ -893,6 +893,21 @@ class TestSubclass(unittest.TestCase): d1 == d2 # not clear if this is supposed to be True or False, # but it used to give a SystemError + @support.cpython_only + def test_bug_31608(self): + # The interpreter used to crash in specific cases where a deque + # subclass returned a non-deque. + class X(deque): + pass + d = X() + def bad___new__(cls, *args, **kwargs): + return [42] + X.__new__ = bad___new__ + with self.assertRaises(TypeError): + d * 42 # shouldn't crash + with self.assertRaises(TypeError): + d + deque([1, 2, 3]) # shouldn't crash + class SubclassWithKwargs(deque): def __init__(self, newarg=1): diff --git a/Misc/NEWS.d/next/Library/2017-10-29-10-37-55.bpo-31608.wkp8Nw.rst b/Misc/NEWS.d/next/Library/2017-10-29-10-37-55.bpo-31608.wkp8Nw.rst new file mode 100644 index 0000000000..d657a86973 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2017-10-29-10-37-55.bpo-31608.wkp8Nw.rst @@ -0,0 +1,2 @@ +Raise a ``TypeError`` instead of crashing if a ``collections.deque`` subclass +returns a non-deque from ``__new__``. Patch by Oren Milman. diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c index d7b344be69..85037d0027 100644 --- a/Modules/_collectionsmodule.c +++ b/Modules/_collectionsmodule.c @@ -514,6 +514,7 @@ deque_inplace_concat(dequeobject *deque, PyObject *other) static PyObject * deque_copy(PyObject *deque) { + PyObject *result; dequeobject *old_deque = (dequeobject *)deque; if (Py_TYPE(deque) == &deque_type) { dequeobject *new_deque; @@ -538,10 +539,19 @@ deque_copy(PyObject *deque) return NULL; } if (old_deque->maxlen < 0) - return PyObject_CallFunction((PyObject *)(Py_TYPE(deque)), "O", deque, NULL); + result = PyObject_CallFunctionObjArgs((PyObject *)(Py_TYPE(deque)), + deque, NULL); else - return PyObject_CallFunction((PyObject *)(Py_TYPE(deque)), "Oi", - deque, old_deque->maxlen, NULL); + result = PyObject_CallFunction((PyObject *)(Py_TYPE(deque)), "Oi", + deque, old_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."); |