check for NULL tp_as_mapping in PySequence_(Get/Set/Del)Slice #9834
diff --git a/Misc/NEWS b/Misc/NEWS
index ca64883..225531b 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -108,6 +108,13 @@
guaranteed to exist in all Python implementations and the names of hash
algorithms available in the current process.
+C-API
+-----
+
+- Issue #9834: Don't segfault in PySequence_GetSlice, PySequence_SetSlice, or
+ PySequence_DelSlice when the object doesn't have any mapping operations
+ defined.
+
Tools/Demos
-----------
diff --git a/Objects/abstract.c b/Objects/abstract.c
index 612271d..4eb33d3 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -1612,7 +1612,7 @@
if (!s) return null_error();
mp = s->ob_type->tp_as_mapping;
- if (mp->mp_subscript) {
+ if (mp && mp->mp_subscript) {
PyObject *res;
PyObject *slice = _PySlice_FromIndices(i1, i2);
if (!slice)
@@ -1690,7 +1690,7 @@
}
mp = s->ob_type->tp_as_mapping;
- if (mp->mp_ass_subscript) {
+ if (mp && mp->mp_ass_subscript) {
int res;
PyObject *slice = _PySlice_FromIndices(i1, i2);
if (!slice)
@@ -1715,7 +1715,7 @@
}
mp = s->ob_type->tp_as_mapping;
- if (mp->mp_ass_subscript) {
+ if (mp && mp->mp_ass_subscript) {
int res;
PyObject *slice = _PySlice_FromIndices(i1, i2);
if (!slice)