gh-88: Add PyList_GetItemRef()

Author: vstinner

docs/api.rst

@@ -170,6 +170,10 @@ Python 3.13
 
    See `PyTime_PerfCounter() documentation <https://docs.python.org/dev/c-api/time.html#c.PyTime_PerfCounter>`__.
 
+.. c:function:: PyObject* PyList_GetItemRef(PyObject *op, Py_ssize_t index)
+
+   See `PyList_GetItemRef() documentation <https://docs.python.org/dev/c-api/list.html#c.PyList_GetItemRef>`__.
+
 
 Not supported:
 

pythoncapi_compat.h

@@ -1286,6 +1286,18 @@ static inline PyObject* Py_GetConstantBorrowed(unsigned int constant_id)
 #endif
 
 
+// gh-114329 added PyList_GetItemRef() to Python 3.13.0a4
+#if PY_VERSION_HEX < 0x030D00A4
+static inline PyObject *
+PyList_GetItemRef(PyObject *op, Py_ssize_t index)
+{
+    PyObject *item = PyList_GetItem(op, index);
+    Py_XINCREF(item);
+    return item;
+}
+#endif
+
+
 #ifdef __cplusplus
 }
 #endif

tests/test_pythoncapi_compat_cext.c

@@ -1480,15 +1480,24 @@ test_list(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
         return NULL;
     }
 
-    PyObject *abc = PyUnicode_FromString("abc");
-    if (abc == NULL) {
-        return NULL;
+    // test PyList_Extend()
+    {
+        PyObject *abc = PyUnicode_FromString("abc");
+        if (abc == NULL) {
+            Py_DECREF(list);
+            return NULL;
+        }
+
+        assert(PyList_Extend(list, abc) == 0);
+        Py_DECREF(abc);
+        assert(PyList_GET_SIZE(list) == 3);
     }
 
-    // test PyList_Extend()
-    assert(PyList_Extend(list, abc) == 0);
-    Py_DECREF(abc);
-    assert(PyList_GET_SIZE(list) == 3);
+    // test PyList_GetItemRef()
+    PyObject *item = PyList_GetItemRef(list, 1);
+    assert(item != NULL);
+    assert(item == PyList_GetItem(list, 1));
+    Py_DECREF(item);
 
     // test PyList_Clear()
     assert(PyList_Clear(list) == 0);