ref: b1d9d2818b21df8234d305b91d2c8e21bea78b6b
dir: /bugs-fixed/space.bad/
" " ~ [[:blank:]] " " ~ [[:space:]] \a !~ [[:blank:]] \a !~ [[:space:]] \b !~ [[:blank:]] \b !~ [[:space:]] \f ~ [[:blank:]] \f ~ [[:space:]] \n ~ [[:blank:]] \n ~ [[:space:]] \r ~ [[:blank:]] \r ~ [[:space:]] \t ~ [[:blank:]] \t ~ [[:space:]] \v ~ [[:blank:]] \v ~ [[:space:]]