359 static PyObject *
360 urj_pyc_shift_ir (urj_pychain_t *self)
361 {
362     urj_chain_t *urc = self->urchain;
363     if (!urj_pyc_precheck (urc, UPRC_CBL))
when considering value == (int)0 from chain.c:363
taking True path
364         return NULL;
365 
366     return urj_py_chkret (urj_tap_chain_shift_instructions (urc));
367 }
returning (PyObject*)NULL without setting an exception