has_many :through regression. behaves as if :uniq => true was set

has_many_through_boom.rb

require 'active_record'


# Print out what version we're running
puts "Active Record #{ActiveRecord::VERSION::STRING}"

# Connect to an in-memory sqlite3 database (more on this in a moment)
ActiveRecord::Base.establish_connection(
  :adapter  => 'sqlite3',
  :database => ':memory:'
)

# Create the minimal database schema necessary to reproduce the bug
ActiveRecord::Schema.define do
  create_table :orders, :force => true do |t|
  end

  create_table :tickets, :force => true do |t|
    t.string :name
  end

  create_table :order_tickets, :force => true do |t|
    t.integer :order_id
    t.integer :ticket_id
  end
end

class Order < ActiveRecord::Base
  has_many :order_tickets
  has_many :tickets, :through => :order_tickets
end

class Ticket < ActiveRecord::Base
  has_many :order_tickets
  has_many :orders, :through => :order_tickets
end

class OrderTicket < ActiveRecord::Base
  belongs_to :order
  belongs_to :ticket
end


ticket = Ticket.create :name => "Standard"

order = Order.create

order.tickets = [ ticket, ticket, ticket ]

puts "Ticket Count: #{order.tickets.reload.count}"
puts "Ticket Collection: #{order.tickets.inspect}"