Psych bug

gistfile1.rb

require 'yaml'
YAML::ENGINE.yamler = 'psych'
puts "Custom encode_with and init_with"
class A
  attr_reader :b
  def initialize(b)
    @b=b
  end
end
class B
  attr_reader :a
  def initialize
    @a=A.new(self)
  end
  #comment this
  def encode_with(c)
    c['a']=@a
  end
  #end comment
  def init_with(c)
    @a=c['a']
  end
end

b = B.new
str= b.to_yaml
puts "YAML:"
puts str

b = YAML::load(str)
puts "References same? #{b.a.b.object_id == b.object_id}"

#Output is 
#$ ruby 1.rb
#Custom encode_with and init_with
#YAML:
#--- !ruby/object:B
#a: &75276480 !ruby/object:A
#  b: !ruby/object:B
#    a: *75276480