YAML cannot restore instance variable of subclass of Hash/Array/String

[anonymous]

This was originally reported by sakazuki [ruby-list:41800]

require 'yaml'

class B < Hash
  def initialize(*v)
    @order = $order
    super
  end
  attr_accessor :order
end

$order = "foo"
b = B.new
$order = "boo"

p Marshal.load(Marshal.dump(b)).order #=> "foo"
p YAML.load(YAML.dump(b)).order       #=> nil