3.13.2: cast in Py_XDECREF causes runtime failures with immortal objects

Bug report

Bug description:

In Python 3.13.2 I use

Py_XDECREF(PyObject *op) 

It is called at the end of a function-call to load an image (cv2.imread) which fails, resulting in a None value (not NULL!). For Python 3.9 Py_XDECREF works just fine, without crash. For Python 3.13.2 the program, compiled with VS2022 (64 Bit), raises a "Run-Time Check Failure #1 - A cast to a smaller data type has caused a loss of data." and my application crashes ("/RTC1 = Basic Runtime Checks enabled").

I followed up the calls:

    Py_DECREF
        _Py_IsImmortal
            #elif SIZEOF_VOID_P > 4
                _Py_CAST(PY_INT32_T, op->ob_refcnt)     <-- crash

The value is

op->ob_refcnt == 0x0000000100000000

To fix this problem, I propose, that the type cast to 32 bit should be changed to

_Py_CAST(PY_INT32_T, op->ob_refcnt & 0xFFFFFFFF)

CPython versions tested on:

3.13

Operating systems tested on:

Windows

从 Py_XDECREF/Py_DECREF 和 _Py_IsImmortal 的调用路径开始，使用报告中的 immortal reference count 重现 Windows VS2022 /RTC1 失败。将 cast 行为与提议的 masking 进行比较，然后使用相关的 CPython 测试验证该失败已得到解决；该 issue 未指定具体的源文件或测试。