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author | Raymond Hettinger <python@rcn.com> | 2016-01-27 05:44:16 (GMT) |
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committer | Raymond Hettinger <python@rcn.com> | 2016-01-27 05:44:16 (GMT) |
commit | 3743432302e9b31d4fe0db31485543a306057fc8 (patch) | |
tree | 44b17d2b0ee2b6d75db1aaa4c931527ab1a35020 /Modules/_collectionsmodule.c | |
parent | d4e51f45a9b82832e95dcc55ba0d8f53ca725824 (diff) | |
download | cpython-3743432302e9b31d4fe0db31485543a306057fc8.zip cpython-3743432302e9b31d4fe0db31485543a306057fc8.tar.gz cpython-3743432302e9b31d4fe0db31485543a306057fc8.tar.bz2 |
Issue #26194: Fix undefined behavior for deque.insert() when len(d) == maxlen
Diffstat (limited to 'Modules/_collectionsmodule.c')
-rw-r--r-- | Modules/_collectionsmodule.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c index 1a33428..b9c4f3b 100644 --- a/Modules/_collectionsmodule.c +++ b/Modules/_collectionsmodule.c @@ -973,10 +973,17 @@ deque_insert(dequeobject *deque, PyObject *args) Py_ssize_t index; Py_ssize_t n = Py_SIZE(deque); PyObject *value; + PyObject *oldvalue; PyObject *rv; if (!PyArg_ParseTuple(args, "nO:insert", &index, &value)) return NULL; + if (deque->maxlen == Py_SIZE(deque)) { + if (index >= deque->maxlen || Py_SIZE(deque) == 0) + Py_RETURN_NONE; + oldvalue = deque_pop(deque, NULL); + Py_DECREF(oldvalue); + } if (index >= n) return deque_append(deque, value); if (index <= -n || index == 0) |