bpo-36374: Fix a possible null pointer dereference (GH-12449)

https://bugs.python.org/issue36374

diff --git a/Misc/NEWS.d/next/Core and Builtins/2019-03-19-15-46-42.bpo-36374.EWKMZE.rst b/Misc/NEWS.d/next/Core and Builtins/2019-03-19-15-46-42.bpo-36374.EWKMZE.rst
new file mode 100644 (file)
index 0000000..2eac301
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2019-03-19-15-46-42.bpo-36374.EWKMZE.rst
@@ -0,0 +1,2 @@
+Fix a possible null pointer dereference in ``merge_consts_recursive()``.
+Patch by Zackery Spytz.

diff --git a/Python/compile.c b/Python/compile.c
index 697833752bb0bdaa6371d12dd0b05ea0b781c5a2..3656a7e00efd939ce027b54572a5efdad2f34dc3 100644 (file)
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -1210,7 +1210,7 @@ merge_consts_recursive(struct compiler *c, PyObject *o)
     PyObject *t = PyDict_SetDefault(c->c_const_cache, key, key);
     if (t != key) {
         // o is registered in c_const_cache.  Just use it.
-        Py_INCREF(t);
+        Py_XINCREF(t);
         Py_DECREF(key);
         return t;
     }