gh-106168: PyTuple_SET_ITEM() now checks the index (#106164)

PyTuple_SET_ITEM() and PyList_SET_ITEM() now check the index argument
with an assertion if Python is built in debug mode or is built with
assertions.

* list_extend() and _PyList_AppendTakeRef() now set the list size
  before calling PyList_SET_ITEM().
* PyStructSequence_GetItem() and PyStructSequence_SetItem() now check
  the index argument: must be lesser than REAL_SIZE(op).
* PyStructSequence_GET_ITEM() and PyStructSequence_SET_ITEM() are now
  aliases to PyStructSequence_GetItem() and
  PyStructSequence_SetItem().

1 files changed, 5 insertions, 8 deletions

diff --git a/Include/structseq.h b/Include/structseq.h
index 9687115..29e24fe 100644
--- a/Include/structseq.h
+++ b/Include/structseq.h
@@ -31,18 +31,15 @@ PyAPI_FUNC(PyTypeObject*) PyStructSequence_NewType(PyStructSequence_Desc *desc);
 
 PyAPI_FUNC(PyObject *) PyStructSequence_New(PyTypeObject* type);
 
+PyAPI_FUNC(void) PyStructSequence_SetItem(PyObject*, Py_ssize_t, PyObject*);
+PyAPI_FUNC(PyObject*) PyStructSequence_GetItem(PyObject*, Py_ssize_t);
+
 #ifndef Py_LIMITED_API
 typedef PyTupleObject PyStructSequence;
-
-/* Macro, *only* to be used to fill in brand new objects */
-#define PyStructSequence_SET_ITEM(op, i, v) PyTuple_SET_ITEM((op), (i), (v))
-
-#define PyStructSequence_GET_ITEM(op, i) PyTuple_GET_ITEM((op), (i))
+#define PyStructSequence_SET_ITEM PyStructSequence_SetItem
+#define PyStructSequence_GET_ITEM PyStructSequence_GetItem
 #endif
 
-PyAPI_FUNC(void) PyStructSequence_SetItem(PyObject*, Py_ssize_t, PyObject*);
-PyAPI_FUNC(PyObject*) PyStructSequence_GetItem(PyObject*, Py_ssize_t);
-
 #ifdef __cplusplus
 }
 #endif