Use PyType_GetDict to safely access tp_dict [3.12]

[cdce8p]

This resolve the Segmenation fault issues with Python 3.12.0b1 - 3.12.0b4. My particular test case, although others in the existing test suite failed as well (when tested with Python 3.12.0b4).

import orjson

def default(obj):
    if isinstance(obj, set):
        return list(obj)
    raise TypeError

print(orjson.dumps({1, 2}, default=default))

For 3.12 it's no longer safe to assume tp_dict is always a PyObject as it can be NULL too for static builtin types now. Instead use PyType_GetDict (new in 3.12) to access it safely.

Requires: PyO3/pyo3#3339

Refs:
https://docs.python.org/3.12/whatsnew/changelog.html?highlight=pytype_getdict#c-api
https://docs.python.org/3.12/c-api/type.html#c.PyType_GetDict
https://docs.python.org/3.12/c-api/typeobj.html#c.PyTypeObject.tp_dict

python/cpython#103912

[ijl]

Thanks. This will wait on the first release candidate and PyO3.

[cdce8p]

PyO3 was released today: https://github.com/PyO3/pyo3/releases/tag/v0.19.2

I've updated the PR to use v0.19.2 now. Besides the change with PyType_GetDict the ref counting in pyo3 for Python 3.12 was changed a bit. See PyO3/pyo3#3335. Pushed another commit to address this.

[ijl]

Thanks, this is on master cherry-picked as 5c8f93d, fa2df4d.

[ijl]

https://github.com/ijl/orjson/releases/tag/3.9.3

[cdce8p]

Awesome! Thanks 🚀