when matching against the empty string, do it directly rather than via a packed string
when matching against the empty string, do it directly rather than via a packed string

darcs-hash:20061219051353-1a7c6-9a762d8c0313957be62a46e05f8b432200a5823c

kirbyfan64/jhc,kirbyfan64/jhc,kirbyfan64/jhc,kirbyfan64/jhc