Bug #4044: Regex matching errors when using \W character class and /i option
http://redmine.ruby-lang.org/issues/show/4044

Author: Ben Hoskings
Status: Open, Priority: Normal
Category: core, Target version: 1.9.2
ruby -v: ruby 1.9.2p0 (2010-08-18 revision 29036) [x86_64-darwin10.4.0]

Hi all,

Josh Bassett and I just discovered an issue with regex matches on ruby-1.9.2p0. (We reduced it while we were hacking on gemcutter.)

The case-insensitive (/i) option together with the non-word character class (\W) match inconsistently against the alphabet. Specifically the regex doesn't match properly against the letters 'k' and 's'.

The following expression demonstrates the problem in irb:

    puts ('a'..'z').to_a.map {|c| [c, c.ord, c[/[^\W]/i] ].inspect }

As a reference, the following two expressions are working properly:

    puts ('a'..'z').to_a.map {|c| [c, c.ord, c[/[^\W]/] ].inspect }
    puts ('a'..'z').to_a.map {|c| [c, c.ord, c[/[\w]/i] ].inspect }

Cheers
Ben Hoskings & Josh Bassett


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