From 6bfb71b0d2d1bcc792dd4e2257578f17cb88dc4a Mon Sep 17 00:00:00 2001
From: Victor Stinner <vstinner@python.org>
Date: Mon, 13 Nov 2023 17:29:55 +0100
Subject: [PATCH] Add PyList_Extend()

---
 docs/api.rst                        |  8 ++++++++
 docs/changelog.rst                  |  5 +++++
 pythoncapi_compat.h                 | 15 +++++++++++++++
 tests/test_pythoncapi_compat_cext.c | 28 ++++++++++++++++++++++++++++
 4 files changed, 56 insertions(+)

diff --git a/docs/api.rst b/docs/api.rst
index d4846db..a0b7ecf 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -121,6 +121,14 @@ Python 3.13
 
    See `PyUnicode_EqualToUTF8AndSize() documentation <https://docs.python.org/dev/c-api/unicode.html#c.PyUnicode_EqualToUTF8AndSize>`__.
 
+.. c:function:: int PyList_Extend(PyObject *list, PyObject *iterable)
+
+   See `PyList_Extend() documentation <https://docs.python.org/dev/c-api/list.html#c.PyList_Extend>`__.
+
+.. c:function:: int PyList_Clear(PyObject *list)
+
+   See `PyList_Clear() documentation <https://docs.python.org/dev/c-api/list.html#c.PyList_Clear>`__.
+
 
 Python 3.12
 -----------
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 4147a4a..25e14d2 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -1,6 +1,11 @@
 Changelog
 =========
 
+* 2023-11-13: Add functions:
+
+  * ``PyList_Extend()``
+  * ``PyList_Clear()``
+
 * 2023-10-04: Add functions:
 
   * ``PyUnicode_EqualToUTF8()``
diff --git a/pythoncapi_compat.h b/pythoncapi_compat.h
index b423fbd..6c67426 100644
--- a/pythoncapi_compat.h
+++ b/pythoncapi_compat.h
@@ -1013,6 +1013,21 @@ PyUnicode_EqualToUTF8(PyObject *unicode, const char *str)
 #endif
 
 
+// gh-111138 added PyList_Extend() and PyList_Clear() to Python 3.13.0a2
+#if PY_VERSION_HEX < 0x030D00A2
+static inline int
+PyList_Extend(PyObject *list, PyObject *iterable)
+{
+    return PyList_SetSlice(list, PY_SSIZE_T_MAX, PY_SSIZE_T_MAX, iterable);
+}
+
+static inline int
+PyList_Clear(PyObject *list)
+{
+    return PyList_SetSlice(list, 0, PY_SSIZE_T_MAX, NULL);
+}
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/tests/test_pythoncapi_compat_cext.c b/tests/test_pythoncapi_compat_cext.c
index 8d8ef38..81cfe6b 100644
--- a/tests/test_pythoncapi_compat_cext.c
+++ b/tests/test_pythoncapi_compat_cext.c
@@ -1395,6 +1395,33 @@ test_unicode(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
 }
 
 
+static PyObject *
+test_list(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
+{
+    PyObject *list = PyList_New(0);
+    if (list == NULL) {
+        return NULL;
+    }
+
+    PyObject *abc = PyUnicode_FromString("abc");
+    if (abc == NULL) {
+        return NULL;
+    }
+
+    // test PyList_Extend()
+    assert(PyList_Extend(list, abc) == 0);
+    Py_DECREF(abc);
+    assert(PyList_GET_SIZE(list) == 3);
+
+    // test PyList_Clear()
+    assert(PyList_Clear(list) == 0);
+    assert(PyList_GET_SIZE(list) == 0);
+
+    Py_DECREF(list);
+    Py_RETURN_NONE;
+}
+
+
 static struct PyMethodDef methods[] = {
     {"test_object", test_object, METH_NOARGS, _Py_NULL},
     {"test_py_is", test_py_is, METH_NOARGS, _Py_NULL},
@@ -1425,6 +1452,7 @@ static struct PyMethodDef methods[] = {
     {"test_managed_dict", test_managed_dict, METH_NOARGS, _Py_NULL},
 #endif
     {"test_unicode", test_unicode, METH_NOARGS, _Py_NULL},
+    {"test_list", test_list, METH_NOARGS, _Py_NULL},
     {_Py_NULL, _Py_NULL, 0, _Py_NULL}
 };