608 static PyObject *
609 urj_pyc_add_register (urj_pychain_t *self, PyObject *args)
610 {
611     char *regname;
612     int reglen;
613     urj_part_t *part;
614     urj_chain_t *urc = self->urchain;
615 
616     if (!PyArg_ParseTuple (args, "si", &regname, &reglen))
when PyArg_ParseTuple() succeeds
taking False path
617         return NULL;
618     if (!urj_pyc_precheck (urc, UPRC_CBL|UPRC_DET))
when considering value == (int)0 from chain.c:618
taking True path
619         return NULL;
620 
621     part = urj_tap_chain_active_part (urc);
622     if (part == NULL)
623     {
624         if (urj_error_get ())
625         {
626             PyErr_SetString (UrjtagError, urj_error_describe ());
627             urj_error_reset ();
628         }
629         else
630             PyErr_SetString (UrjtagError,
631                              _("liburjtag BUG: unknown urjtag error"));
632         return NULL;
633     }
634 
635     return urj_py_chkret (urj_part_data_register_define (part, regname, reglen));
636 }
returning (PyObject*)NULL without setting an exception