The refusal table exercised slash, leading dot and leading dash but never a control character, so that branch of the guard could have been dropped without a test noticing. Add a newline and a tab case, labelled so the value stays out of the output.
The refusal table exercised slash, leading dot and leading dash but never a control character, so that branch of the guard could have been dropped without a test noticing. Add a newline and a tab case, labelled so the value stays out of the output.