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author | Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> | 2018-03-06 23:47:40 -0800 |
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committer | GitHub <noreply@github.com> | 2018-03-06 23:47:40 -0800 |
commit | d824b4e4afbe9cf02310e39b14402fb2aa271f8f (patch) | |
tree | 171067fcbaee01eb008b5858cd18b719996f123c /Modules/_abc.c | |
parent | c4d77a661138debbbe584b8b08410afc8719a9b1 (diff) | |
download | cpython-git-d824b4e4afbe9cf02310e39b14402fb2aa271f8f.tar.gz |
bpo-32999: Fix ABC.__subclasscheck__ crash (GH-6002)
(cherry picked from commit fc7df0e664198cb05cafd972f190a18ca422989c)
Co-authored-by: INADA Naoki <methane@users.noreply.github.com>
Diffstat (limited to 'Modules/_abc.c')
-rw-r--r-- | Modules/_abc.c | 37 |
1 files changed, 25 insertions, 12 deletions
diff --git a/Modules/_abc.c b/Modules/_abc.c index 504e23d9a7..862883987f 100644 --- a/Modules/_abc.c +++ b/Modules/_abc.c @@ -16,6 +16,7 @@ _Py_IDENTIFIER(__abstractmethods__); _Py_IDENTIFIER(__class__); _Py_IDENTIFIER(__dict__); _Py_IDENTIFIER(__bases__); +_Py_IDENTIFIER(__mro__); _Py_IDENTIFIER(_abc_impl); _Py_IDENTIFIER(__subclasscheck__); _Py_IDENTIFIER(__subclasshook__); @@ -568,7 +569,7 @@ _abc__abc_subclasscheck_impl(PyObject *module, PyObject *self, PyObject *subclass) /*[clinic end generated code: output=b56c9e4a530e3894 input=1d947243409d10b8]*/ { - PyObject *ok, *mro, *subclasses = NULL, *result = NULL; + PyObject *ok, *mro = NULL, *subclasses = NULL, *result = NULL; Py_ssize_t pos; int incache; _abc_data *impl = _get_impl(self); @@ -637,20 +638,31 @@ _abc__abc_subclasscheck_impl(PyObject *module, PyObject *self, } Py_DECREF(ok); - /* 4. Check if it's a direct subclass. */ - mro = ((PyTypeObject *)subclass)->tp_mro; - assert(PyTuple_Check(mro)); - for (pos = 0; pos < PyTuple_GET_SIZE(mro); pos++) { - PyObject *mro_item = PyTuple_GET_ITEM(mro, pos); - if (mro_item == NULL) { + /* 4. Check if it's a direct subclass. + * + * if cls in getattr(subclass, '__mro__', ()): + * cls._abc_cache.add(subclass) + * return True + */ + if (_PyObject_LookupAttrId(subclass, &PyId___mro__, &mro) < 0) { + goto end; + } + if (mro != NULL) { + if (!PyTuple_Check(mro)) { + // Python version supports non-tuple iterable. Keep it as + // implementation detail. + PyErr_SetString(PyExc_TypeError, "__mro__ is not a tuple"); goto end; } - if ((PyObject *)self == mro_item) { - if (_add_to_weak_set(&impl->_abc_cache, subclass) < 0) { + for (pos = 0; pos < PyTuple_GET_SIZE(mro); pos++) { + PyObject *mro_item = PyTuple_GET_ITEM(mro, pos); + if ((PyObject *)self == mro_item) { + if (_add_to_weak_set(&impl->_abc_cache, subclass) < 0) { + goto end; + } + result = Py_True; goto end; } - result = Py_True; - goto end; } } @@ -690,7 +702,8 @@ _abc__abc_subclasscheck_impl(PyObject *module, PyObject *self, result = Py_False; end: - Py_XDECREF(impl); + Py_DECREF(impl); + Py_XDECREF(mro); Py_XDECREF(subclasses); Py_XINCREF(result); return result; |