Enable deferred ref counts for MRO tuple.

nascheme · nascheme · commit d4c0df342ae5 · 2025-06-10T16:41:06.000-07:00
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
@@ -5930,6 +5930,10 @@ find_name_in_mro(PyTypeObject *type, PyObject *name, int *error)
         }
     }
 
+    if (!_Py_IsOwnedByCurrentThread(mro)) {
+        PyUnstable_Object_EnableDeferredRefcount(mro);
+    }
+
     PyObject *res = NULL;
     Py_ssize_t n = PyTuple_GET_SIZE(mro);
     for (Py_ssize_t i = 0; i < n; i++) {

Original file line number	Diff line number	Diff line change
`@@ -5930,6 +5930,10 @@ find_name_in_mro(PyTypeObject type, PyObject name, int *error)`
`5930`	`5930`	`}`
`5931`	`5931`	`}`
`5932`	`5932`
	`5933`	`+ if (!_Py_IsOwnedByCurrentThread(mro)) {`
	`5934`	`+ PyUnstable_Object_EnableDeferredRefcount(mro);`
	`5935`	`+ }`
	`5936`	`+`
`5933`	`5937`	`PyObject *res = NULL;`
`5934`	`5938`	`Py_ssize_t n = PyTuple_GET_SIZE(mro);`
`5935`	`5939`	`for (Py_ssize_t i = 0; i < n; i++) {`