Bug #10670
Updated by nobu (Nobuyoshi Nakada) almost 10 years ago
The following simple script illustrates the issue: ~~~ruby ESCAPE_PLAIN = /\A[\x5B]*\z/m.freeze 0x5B.chr(::Encoding::UTF_8) =~ ESCAPE_PLAIN 0x5B.chr =~ ESCAPE_PLAIN ~~~ `\x5B` \x5B is `']'`, ']', run all lines above and get _in `=~': empty char-class: /\A[\x5B]*\z/m (RegexpError)_ Comment out either the first or second usage and the error goes away.