risk-averse coding of the parser kernel: check for `!action` rather than `action === 0` as `!action` is the 'error occurred in state' marker in the kernel throughout.
risk-averse coding of the parser kernel: check for `!action` rather than `action === 0` as `!action` is the 'error occurred in state' marker in the kernel throughout.

GerHobbelt/jison,GerHobbelt/jison,GerHobbelt/jison,GerHobbelt/jison