commit 6a56790e0b50846f1f968e48c3a321c148b5e6cd
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Wed May 02 02:50:48 2018 -0700
committer GitHub <noreply@github.com> Wed May 02 02:50:48 2018 -0700
tree a7c77073584bff62d457e097aee1f4c60928e8e8
parent 01e19f8fedb1e02476c4e42d387829135c9e76a1

bpo-33391: Fix refleak in set_symmetric_difference (GH-6670)

(cherry picked from commit 491bbedc209fea314a04cb3015da68fb0aa63238)

Co-authored-by: lekma <lekmalek@gmail.com>

Misc/NEWS.d/next/Core and Builtins/2018-05-02-08-36-03.bpo-33391.z4a7rb.rst

diff --git a/Misc/NEWS.d/next/Core and Builtins/2018-05-02-08-36-03.bpo-33391.z4a7rb.rst b/Misc/NEWS.d/next/Core and Builtins/2018-05-02-08-36-03.bpo-33391.z4a7rb.rst
new file mode 100644
index 0000000..ab17aa4
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2018-05-02-08-36-03.bpo-33391.z4a7rb.rst
@@ -0,0 +1 @@
+Fix a leak in set_symmetric_difference().

Objects/setobject.c

diff --git a/Objects/setobject.c b/Objects/setobject.c
index 47db6b2..ce35aa2 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -1744,8 +1744,10 @@
     if (otherset == NULL)
         return NULL;
     rv = set_symmetric_difference_update(otherset, (PyObject *)so);
-    if (rv == NULL)
+    if (rv == NULL) {
+        Py_DECREF(otherset);
         return NULL;
+    }
     Py_DECREF(rv);
     return (PyObject *)otherset;
 }