Ruby 1.9 Delegator bug

gistfile1.rb

require 'delegate'

A = Struct.new(:a)
class B < DelegateClass(A)
  attr_accessor :foo
end
b = B.new(A.new(5))
puts b.inspect
puts b.respond_to?(:foo)

module Kernel
  def should
    raise self.methods.grep(/foo/).inspect # should include "foo", as it does on 1.8.7
  end
end

b.should