diff options
| -rw-r--r-- | Modules/_collectionsmodule.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c index 5dea8cbbd1..66f5939c60 100644 --- a/Modules/_collectionsmodule.c +++ b/Modules/_collectionsmodule.c @@ -1045,6 +1045,9 @@ deque_clear(dequeobject *deque) Py_ssize_t n; PyObject *item; + if (Py_SIZE(deque) == 0) + return; + /* During the process of clearing a deque, decrefs can cause the deque to mutate. To avoid fatal confusion, we have to make the deque empty before clearing the blocks and never refer to @@ -1423,7 +1426,8 @@ deque_init(dequeobject *deque, PyObject *args, PyObject *kwdargs) } } deque->maxlen = maxlen; - deque_clear(deque); + if (Py_SIZE(deque) > 0) + deque_clear(deque); if (iterable != NULL) { PyObject *rv = deque_extend(deque, iterable); if (rv == NULL) |