[Python-checkins] bpo-34899: Fix a possible assertion failure due to int_from_bytes_impl() (GH-9705)

[Serhiy Storchaka]

https://github.com/python/cpython/commit/7bb9cd0a6766fd3e7b3c1e8f2315304ae192b34c
commit: 7bb9cd0a6766fd3e7b3c1e8f2315304ae192b34c
branch: master
author: Zackery Spytz <zspytz at gmail.com>
committer: Serhiy Storchaka <storchaka at gmail.com>
date: 2018-10-06T00:02:23+03:00
summary:

bpo-34899: Fix a possible assertion failure due to int_from_bytes_impl() (GH-9705)

The _PyLong_FromByteArray() call in int_from_bytes_impl() was
unchecked.

files:
M Objects/longobject.c

diff --git a/Objects/longobject.c b/Objects/longobject.c
index afe30bc0532a..ae3a98cc791c 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -5403,7 +5403,7 @@ int_from_bytes_impl(PyTypeObject *type, PyObject *bytes_obj,
         little_endian, is_signed);
     Py_DECREF(bytes);
 
-    if (type != &PyLong_Type) {
+    if (long_obj != NULL && type != &PyLong_Type) {
         Py_SETREF(long_obj, PyObject_CallFunctionObjArgs((PyObject *)type,
                                                          long_obj, NULL));
     }