[3.8] bpo-39453: Fix contains method of list to hold strong references (GH-18204)
diff --git a/Objects/listobject.c b/Objects/listobject.c
index 73afc44..3044408 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -445,12 +445,16 @@
static int
list_contains(PyListObject *a, PyObject *el)
{
+ PyObject *item;
Py_ssize_t i;
int cmp;
- for (i = 0, cmp = 0 ; cmp == 0 && i < Py_SIZE(a); ++i)
- cmp = PyObject_RichCompareBool(el, PyList_GET_ITEM(a, i),
- Py_EQ);
+ for (i = 0, cmp = 0 ; cmp == 0 && i < Py_SIZE(a); ++i) {
+ item = PyList_GET_ITEM(a, i);
+ Py_INCREF(item);
+ cmp = PyObject_RichCompareBool(el, item, Py_EQ);
+ Py_DECREF(item);
+ }
return cmp;
}