The snake case feature filters candidate methods and turns them into snake case. This works fine for built-in classes. The assumption is that all methods come from the tp_methods list. This assumption is not correct when applied to user defined classes. The methods have no static source in this case. To distinguish here, we inspect the tp_methods list. If it is empty, we assume a user defined class and do nothing. A forgotten initialization in feature.py was added, too. As a note: RHEL has such an old Python version that does not have MethodDescriptorType in the types module. [ChangeLog][PySide6] snake_case handling now does explicitly not touch user defined classes. Fixes: PYSIDE-1702 Pick-to: 6.2 Change-Id: Idfa16cdc50cb7234c1d2f473dfae3a568887547e Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>