Add some more assertions to _PyObject_VisitType.

ZeroIntensity · ZeroIntensity · commit c58e4d0c117c · 2025-09-01T10:19:18.000-04:00
diff --git a/Objects/object.c b/Objects/object.c
@@ -3388,6 +3388,9 @@ PyUnstable_Object_IsUniquelyReferenced(PyObject *op)
 int _PyObject_VisitType(PyObject *op, visitproc visit, void *arg)
 {
     assert(op != NULL);
-    Py_VISIT(Py_TYPE(op));
+    PyTypeObject *tp = Py_TYPE(op);
+    assert(PyType_HasFeature(tp, Py_TPFLAGS_HEAPTYPE));
+    assert(!PyType_HasFeature(tp, Py_TPFLAGS_IMMUTABLETYPE));
+    Py_VISIT(tp);
     return 0;
 }

Original file line number	Diff line number	Diff line change
`@@ -3388,6 +3388,9 @@ PyUnstable_Object_IsUniquelyReferenced(PyObject *op)`
`3388`	`3388`	`int _PyObject_VisitType(PyObject op, visitproc visit, void arg)`
`3389`	`3389`	`{`
`3390`	`3390`	`assert(op != NULL);`
`3391`		`- Py_VISIT(Py_TYPE(op));`
	`3391`	`+ PyTypeObject *tp = Py_TYPE(op);`
	`3392`	`+ assert(PyType_HasFeature(tp, Py_TPFLAGS_HEAPTYPE));`
	`3393`	`+ assert(!PyType_HasFeature(tp, Py_TPFLAGS_IMMUTABLETYPE));`
	`3394`	`+ Py_VISIT(tp);`
`3392`	`3395`	`return 0;`
`3393`	`3396`	`}`