sys_getwindowsversion_impl might potentially swallow errors in sysmodule.c

[sobolevn]

Bug report

While merging #115321 I've noticed a similar issue to #115320:

cpython/Python/sysmodule.c

Lines 1661 to 1699 in 207030f

	PyStructSequence_SET_ITEM(version, pos++, PyLong_FromLong(ver.dwMajorVersion));
	PyStructSequence_SET_ITEM(version, pos++, PyLong_FromLong(ver.dwMinorVersion));
	PyStructSequence_SET_ITEM(version, pos++, PyLong_FromLong(ver.dwBuildNumber));
	PyStructSequence_SET_ITEM(version, pos++, PyLong_FromLong(ver.dwPlatformId));
	PyStructSequence_SET_ITEM(version, pos++, PyUnicode_FromWideChar(ver.szCSDVersion, -1));
	PyStructSequence_SET_ITEM(version, pos++, PyLong_FromLong(ver.wServicePackMajor));
	PyStructSequence_SET_ITEM(version, pos++, PyLong_FromLong(ver.wServicePackMinor));
	PyStructSequence_SET_ITEM(version, pos++, PyLong_FromLong(ver.wSuiteMask));
	PyStructSequence_SET_ITEM(version, pos++, PyLong_FromLong(ver.wProductType));
	// GetVersion will lie if we are running in a compatibility mode.
	// We need to read the version info from a system file resource
	// to accurately identify the OS version. If we fail for any reason,
	// just return whatever GetVersion said.
	PyObject *realVersion = _sys_getwindowsversion_from_kernel32();
	if (!realVersion) {
	PyErr_Clear();
	realVersion = Py_BuildValue("(kkk)",
	ver.dwMajorVersion,
	ver.dwMinorVersion,
	ver.dwBuildNumber
	);
	}
	if (realVersion) {
	PyStructSequence_SET_ITEM(version, pos++, realVersion);
	}
	if (PyErr_Occurred()) {
	Py_DECREF(version);
	return NULL;
	}
	if (PyObject_SetAttrString(module, "_cached_windows_version", version) < 0) {
	Py_DECREF(version);
	return NULL;
	}
	return version;

It can also overwrite errors, I will send a PR similar to #115321 to fix this as well.

Linked PRs

• gh-116326: Handler errors correctly in getwindowsversion in sysmodule #116339
• [3.12] gh-116326: Handler errors correctly in getwindowsversion in sysmodule (GH-116339) #116354
• [3.11] gh-116326: Handler errors correctly in getwindowsversion in sysmodule (GH-116339) #116388