A class of associated object is not equal to the original one.

I found some strange behavior with 3.0.3. (ruby 1.8.7 (2010-08-16 patchlevel 302) [i686-linux])

Please see the code:

database:

# create table users (id integer auto_increment, primary key (id));
# create table items (id integer auto_increment, user_id integer, primary key (id));
# insert into users (id) values (1);
# insert into items (user_id) values (1);

a.rb:

require 'rubygems'
require 'active_support/dependencies'
require 'active_record'

ActiveRecord::Base.establish_connection(
  # DB settings
)

class User < ActiveRecord::Base
  has_many :items
end

begin
  require 'item'
rescue
end

module X
end

require 'item'

u = User.first
item = u.items.first
p item
p item.class
p item.class.object_id, Item.object_id # should be same but differ
p item.instance_of?(Item) # should be true but becomes false

item.rb:

class Item < ActiveRecord::Base
  include X
end

I put two files a.rb and item.rb.

When I executed a.rb (ruby a.rb), I got different object_id between item.class and Item, and item.instance_of?(Item) became false.

I could not fix correctly. But I found that if the line in ActiveSupport::Dependencies#remove_contant (call of constantize)

constantize(const).before_remove_const if constantize(const).respond_to?(:before_remove_const)

is commented out, the problem disappears.