Issue 8420: Fix ref counting problem in set_repr().
diff --git a/Objects/setobject.c b/Objects/setobject.c
index c3eabf5..9447441 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -601,10 +601,8 @@
 
 	listrepr = PyObject_Repr(keys);
 	Py_DECREF(keys);
-	if (listrepr == NULL) {
-		Py_DECREF(keys);
+	if (listrepr == NULL)
 		goto done;
-	}
 	newsize = PyUnicode_GET_SIZE(listrepr);
 	result = PyUnicode_FromUnicode(NULL, newsize);
 	if (result) {