From: Ammar Askar <ammar@ammaraskar.com>
Date: Wed, 6 Nov 2019 15:40:06 +0000 (-0500)
Subject: bpo-16575: Fix refleak on passing unions in ctypes (GH-17064)
X-Git-Tag: v3.7.6rc1~64
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=484edbf9bf1a9e6bae0fcb10a0c165b89ea79295;p=thirdparty%2FPython%2Fcpython.git

bpo-16575: Fix refleak on passing unions in ctypes (GH-17064)

The master and 3.8 versions of the previous change work as expected
because we perform the lookup for the `from_param` after the union
check. However, in 3.7, this lookup happens before the union
validation and so we must decrease the reference for `cnv` before
returning.
---

diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index d2ce1b074348..0e209c33a80a 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -2285,6 +2285,7 @@ converters_from_argtypes(PyObject *ob)
             if (stgdict->flags & TYPEFLAG_HASUNION) {
                 Py_DECREF(converters);
                 Py_DECREF(ob);
+                Py_DECREF(cnv);
                 if (!PyErr_Occurred()) {
                     PyErr_Format(PyExc_TypeError,
                                  "item %zd in _argtypes_ passes a union by "