ref: c7361cd72fa0032855b87f2a092cda0c750feb5a
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:]]