bpo-36946:Fix possible signed integer overflow when handling slices. (GH-15639)

This is a complement to PR 13375.

1 files changed, 4 insertions, 2 deletions

diff --git a/Objects/listobject.c b/Objects/listobject.c
index 5fca08ea36..645742b801 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -2789,7 +2789,8 @@ list_subscript(PyListObject* self, PyObject* item)
         return list_item(self, i);
     }
     else if (PySlice_Check(item)) {
-        Py_ssize_t start, stop, step, slicelength, cur, i;
+        Py_ssize_t start, stop, step, slicelength, i;
+        size_t cur;
         PyObject* result;
         PyObject* it;
         PyObject **src, **dest;
@@ -2925,7 +2926,8 @@ list_ass_subscript(PyListObject* self, PyObject* item, PyObject* value)
             /* assign slice */
             PyObject *ins, *seq;
             PyObject **garbage, **seqitems, **selfitems;
-            Py_ssize_t cur, i;
+            Py_ssize_t i;
+            size_t cur;
 
             /* protect against a[::-1] = a */
             if (self == (PyListObject*)value) {