New warning: "‘subobj’ may be used uninitialized in this function" in Objects/bytes_methods.c

[sobolevn]

Example:

This looks like a false-positive, because subobj is always initialized in stringlib_parse_args_finds(function_name, args, &subobj, &start, &end):

cpython/Objects/bytes_methods.c

Lines 770 to 786 in 87be8d9

	static PyObject *
	_Py_bytes_tailmatch(const char *str, Py_ssize_t len,
	const char *function_name, PyObject *args,
	int direction)
	{
	Py_ssize_t start = 0;
	Py_ssize_t end = PY_SSIZE_T_MAX;
	PyObject *subobj;
	int result;
	if (!stringlib_parse_args_finds(function_name, args, &subobj, &start, &end))
	return NULL;
	if (PyTuple_Check(subobj)) {
	Py_ssize_t i;
	for (i = 0; i < PyTuple_GET_SIZE(subobj); i++) {
	result = tailmatch(str, len, PyTuple_GET_ITEM(subobj, i),
	start, end, direction);

Morever, it is used before in PyTuple_Check(subobj).

Any ideas on how to fix / silence it?
And why we get this warning only now? The code was not changed for 10 months.

Linked PRs

• gh-102941: Fix "‘subobj’ may be used uninitialized in this function" warning in bytes_methods.c #102942

[sobolevn]

Maybe adding = NULL?