gistfile1.rb

# Activate the gem you are reporting the issue against.
gem 'activerecord', '4.1.1'
require 'active_record'
require 'minitest/autorun'
require 'logger'

# Ensure backward compatibility with Minitest 4
Minitest::Test = MiniTest::Unit::TestCase unless defined?(Minitest::Test)

# This connection will do for database-independent bug reports.
ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: ':memory:')
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
    create_table :people do |t|
    end
    create_table :houses do |t|
        t.references :person
    end
    create_table :colors do |t|
        t.references :house
        t.string :color
    end
    create_table :conditions do |t|
        t.string :condition
    end
    create_table :conditions_houses do |t|
        t.references :condition
        t.references :house
    end
end

class Color < ActiveRecord::Base
    belongs_to :house
end

class Condition < ActiveRecord::Base
    has_and_belongs_to_many :houses
end

class House < ActiveRecord::Base
    has_many :colors
    belongs_to :person

    has_and_belongs_to_many :conditions

    scope :damaged, -> { joins(:conditions).where(:'conditions.condition' => 'damaged') }
end

class Person < ActiveRecord::Base
    has_many :houses
    has_many :colors, :through => :houses
    
    has_many :damaged_houses, -> { damaged }, :class_name => "House"
    has_many :damaged_colors, through: :damaged_houses, :source => :colors
end

class BugTest < Minitest::Test
    def test_association_stuff
        Condition.create(condition: :damaged)
        house = House.create(conditions: [Condition.first])
        person = Person.create
        house.person = person
        color = Color.create
        house.colors = [color]
        house.save

        assert_equal 1, person.houses.count
        assert_equal 1, person.damaged_houses.count
 
        assert_equal 1, person.colors.count
        assert_equal 1, person.damaged_colors.count
  end
end