merges rails

98 files changed, 2114 insertions, 1334 deletions

diff --git a/.gitignore b/.gitignore
index 35402a22f7..8daa1e4dcd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,6 +10,7 @@ activerecord/doc
 actionpack/doc
 actionmailer/doc
 activesupport/doc
+activesupport/test/tmp
 activemodel/test/fixtures/fixture_database.sqlite3
 actionpack/test/tmp
 activesupport/test/fixtures/isolation_test
diff --git a/actionmailer/test/asset_host_test.rb b/actionmailer/test/asset_host_test.rb
index 069860ff06..b24eca5fbb 100644
--- a/actionmailer/test/asset_host_test.rb
+++ b/actionmailer/test/asset_host_test.rb
@@ -29,7 +29,7 @@ class AssetHostTest < Test::Unit::TestCase
     assert_equal %Q{<img alt="Somelogo" src="http://www.example.com/images/somelogo.png" />}, mail.body.to_s.strip
   end
 
-  def test_asset_host_as_one_arguement_proc
+  def test_asset_host_as_one_argument_proc
     AssetHostMailer.config.asset_host = Proc.new { |source|
       if source.starts_with?('/images')
         "http://images.example.com"
@@ -41,7 +41,7 @@ class AssetHostTest < Test::Unit::TestCase
     assert_equal %Q{<img alt="Somelogo" src="http://images.example.com/images/somelogo.png" />}, mail.body.to_s.strip
   end
 
-  def test_asset_host_as_two_arguement_proc
+  def test_asset_host_as_two_argument_proc
     ActionController::Base.config.asset_host = Proc.new {|source,request|
       if request && request.ssl?
         "https://www.example.com"
diff --git a/actionmailer/test/base_test.rb b/actionmailer/test/base_test.rb
index 7ed9d4a5c0..1b793d255e 100644
--- a/actionmailer/test/base_test.rb
+++ b/actionmailer/test/base_test.rb
@@ -32,21 +32,21 @@ class BaseTest < ActiveSupport::TestCase
   end
 
   test "mail() with bcc, cc, content_type, charset, mime_version, reply_to and date" do
-    @time = Time.now.beginning_of_day.to_datetime
+    time  = Time.now.beginning_of_day.to_datetime
     email = BaseMailer.welcome(:bcc => 'bcc@test.lindsaar.net',
                                :cc  => 'cc@test.lindsaar.net',
                                :content_type => 'multipart/mixed',
                                :charset => 'iso-8559-1',
                                :mime_version => '2.0',
                                :reply_to => 'reply-to@test.lindsaar.net',
-                               :date => @time)
+                               :date => time)
     assert_equal(['bcc@test.lindsaar.net'],             email.bcc)
     assert_equal(['cc@test.lindsaar.net'],              email.cc)
     assert_equal('multipart/mixed; charset=iso-8559-1', email.content_type)
     assert_equal('iso-8559-1',                          email.charset)
     assert_equal('2.0',                                 email.mime_version)
     assert_equal(['reply-to@test.lindsaar.net'],        email.reply_to)
-    assert_equal(@time,                                 email.date)
+    assert_equal(time,                                  email.date)
   end
 
   test "mail() renders the template using the method being processed" do
diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index ee9d30e1fb..fc3410ba6e 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -1,5 +1,9 @@
 *Rails 3.1.0 (unreleased)*
 
+* ActionDispatch::MiddlewareStack now uses composition over inheritance. It is
+no longer an array which means there may be methods missing that were not
+tested.
+
 * Add an :authenticity_token option to form_tag for custom handling or to omit the token (pass :authenticity_token => false).  [Jakub Kuźma, Igor Wiedler]
 
 * HTML5 button_tag helper. [Rizwan Reza]
diff --git a/actionpack/lib/action_controller/caching/actions.rb b/actionpack/lib/action_controller/caching/actions.rb
index baff6d4be9..2c8a6e4d4d 100644
--- a/actionpack/lib/action_controller/caching/actions.rb
+++ b/actionpack/lib/action_controller/caching/actions.rb
@@ -103,12 +103,14 @@ module ActionController #:nodoc:
       end
 
       def _save_fragment(name, options)
-        return unless caching_allowed?
-
         content = response_body
         content = content.join if content.is_a?(Array)
 
-        write_fragment(name, content, options)
+        if caching_allowed?
+          write_fragment(name, content, options)
+        else
+          content
+        end
       end
 
     protected
diff --git a/actionpack/lib/action_controller/metal.rb b/actionpack/lib/action_controller/metal.rb
index b2c8053584..e5db31061b 100644
--- a/actionpack/lib/action_controller/metal.rb
+++ b/actionpack/lib/action_controller/metal.rb
@@ -36,7 +36,7 @@ module ActionController
       action = action.to_s
       raise "MiddlewareStack#build requires an app" unless app
 
-      reverse.inject(app) do |a, middleware|
+      middlewares.reverse.inject(app) do |a, middleware|
         middleware.valid?(action) ?
           middleware.build(a) : a
       end
diff --git a/actionpack/lib/action_dispatch/middleware/stack.rb b/actionpack/lib/action_dispatch/middleware/stack.rb
index e3cd779756..a4308f528c 100644
--- a/actionpack/lib/action_dispatch/middleware/stack.rb
+++ b/actionpack/lib/action_dispatch/middleware/stack.rb
@@ -2,17 +2,26 @@ require "active_support/inflector/methods"
 require "active_support/dependencies"
 
 module ActionDispatch
-  class MiddlewareStack < Array
+  class MiddlewareStack
     class Middleware
-      attr_reader :args, :block
+      attr_reader :args, :block, :name, :classcache
 
       def initialize(klass_or_name, *args, &block)
-        @ref = ActiveSupport::Dependencies::Reference.new(klass_or_name)
+        @klass = nil
+
+        if klass_or_name.respond_to?(:name)
+          @klass = klass_or_name
+          @name  = @klass.name
+        else
+          @name  = klass_or_name.to_s
+        end
+
+        @classcache = ActiveSupport::Dependencies::Reference
         @args, @block = args, block
       end
 
       def klass
-        @ref.get
+        @klass || classcache[@name]
       end
 
       def ==(middleware)
@@ -22,7 +31,7 @@ module ActionDispatch
         when Class
           klass == middleware
         else
-          normalize(@ref.name) == normalize(middleware)
+          normalize(@name) == normalize(middleware)
         end
       end
 
@@ -41,18 +50,39 @@ module ActionDispatch
       end
     end
 
-    # Use this instead of super to work around a warning.
-    alias :array_initialize :initialize
+    include Enumerable
+
+    attr_accessor :middlewares
 
     def initialize(*args)
-      array_initialize(*args)
+      @middlewares = []
       yield(self) if block_given?
     end
 
+    def each
+      @middlewares.each { |x| yield x }
+    end
+
+    def size
+      middlewares.size
+    end
+
+    def last
+      middlewares.last
+    end
+
+    def [](i)
+      middlewares[i]
+    end
+
+    def initialize_copy(other)
+      self.middlewares = other.middlewares.dup
+    end
+
     def insert(index, *args, &block)
       index = assert_index(index, :before)
       middleware = self.class::Middleware.new(*args, &block)
-      super(index, middleware)
+      middlewares.insert(index, middleware)
     end
 
     alias_method :insert_before, :insert
@@ -67,21 +97,25 @@ module ActionDispatch
       delete(target)
     end
 
+    def delete(target)
+      middlewares.delete target
+    end
+
     def use(*args, &block)
       middleware = self.class::Middleware.new(*args, &block)
-      push(middleware)
+      middlewares.push(middleware)
     end
 
     def build(app = nil, &block)
       app ||= block
       raise "MiddlewareStack#build requires an app" unless app
-      reverse.inject(app) { |a, e| e.build(a) }
+      middlewares.reverse.inject(app) { |a, e| e.build(a) }
     end
 
   protected
 
     def assert_index(index, where)
-      i = index.is_a?(Integer) ? index : self.index(index)
+      i = index.is_a?(Integer) ? index : middlewares.index(index)
       raise "No such middleware to insert #{where}: #{index.inspect}" unless i
       i
     end
diff --git a/actionpack/lib/action_dispatch/middleware/static.rb b/actionpack/lib/action_dispatch/middleware/static.rb
index 913b899e20..c57f694c4d 100644
--- a/actionpack/lib/action_dispatch/middleware/static.rb
+++ b/actionpack/lib/action_dispatch/middleware/static.rb
@@ -3,10 +3,10 @@ require 'rack/utils'
 module ActionDispatch
   class FileHandler
     def initialize(at, root)
-      @at, @root = at.chomp('/'), root.chomp('/')
-      @compiled_at = (Regexp.compile(/^#{Regexp.escape(at)}/) unless @at.blank?)
-      @compiled_root = Regexp.compile(/^#{Regexp.escape(root)}/)
-      @file_server = ::Rack::File.new(@root)
+      @at, @root     = at.chomp('/'), root.chomp('/')
+      @compiled_at   = @at.blank? ? nil : /^#{Regexp.escape(at)}/
+      @compiled_root = /^#{Regexp.escape(root)}/
+      @file_server   = ::Rack::File.new(@root)
     end
 
     def match?(path)
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index 4b4e9da173..fc86d52a3a 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -50,12 +50,13 @@ module ActionDispatch
       private
 
         def controller_reference(controller_param)
+          controller_name = "#{controller_param.camelize}Controller"
+
           unless controller = @controllers[controller_param]
-            controller_name = "#{controller_param.camelize}Controller"
             controller = @controllers[controller_param] =
-              ActiveSupport::Dependencies.ref(controller_name)
+              ActiveSupport::Dependencies.reference(controller_name)
           end
-          controller.get
+          controller.get(controller_name)
         end
 
         def dispatch(controller, action, env)
diff --git a/actionpack/lib/action_view/helpers/asset_tag_helpers/javascript_tag_helpers.rb b/actionpack/lib/action_view/helpers/asset_tag_helpers/javascript_tag_helpers.rb
index b9126af944..82bbfcc7d2 100644
--- a/actionpack/lib/action_view/helpers/asset_tag_helpers/javascript_tag_helpers.rb
+++ b/actionpack/lib/action_view/helpers/asset_tag_helpers/javascript_tag_helpers.rb
@@ -69,7 +69,7 @@ module ActionView
           def register_javascript_expansion(expansions)
             js_expansions = JavascriptIncludeTag.expansions
             expansions.each do |key, values|
-              js_expansions[key] = (js_expansions[key] || []) | Array(values) if values
+              js_expansions[key] = (js_expansions[key] || []) | Array(values)
             end
           end
         end
diff --git a/actionpack/lib/action_view/helpers/asset_tag_helpers/stylesheet_tag_helpers.rb b/actionpack/lib/action_view/helpers/asset_tag_helpers/stylesheet_tag_helpers.rb
index f3e041de95..a48c87b49a 100644
--- a/actionpack/lib/action_view/helpers/asset_tag_helpers/stylesheet_tag_helpers.rb
+++ b/actionpack/lib/action_view/helpers/asset_tag_helpers/stylesheet_tag_helpers.rb
@@ -46,7 +46,7 @@ module ActionView
           def register_stylesheet_expansion(expansions)
             style_expansions = StylesheetIncludeTag.expansions
             expansions.each do |key, values|
-              style_expansions[key] = (style_expansions[key] || []) | Array(values) if values
+              style_expansions[key] = (style_expansions[key] || []) | Array(values)
             end
           end
         end
diff --git a/actionpack/lib/action_view/helpers/form_helper.rb b/actionpack/lib/action_view/helpers/form_helper.rb
index befaa3e8d9..669ccd2a2d 100644
--- a/actionpack/lib/action_view/helpers/form_helper.rb
+++ b/actionpack/lib/action_view/helpers/form_helper.rb
@@ -262,6 +262,24 @@ module ActionView
       #     ...
       #   </form>
       #
+      # === Removing hidden model id's
+      #
+      # The form_for method automatically includes the model id as a hidden field in the form.
+      # This is used to maintain the correlation between the form data and it's associated model.
+      # Some ORM systems do not use id's on nested models so in this case you want to be able
+      # to disable the hidden id.
+      #
+      # In the following example the Post model has many Comments stored within it in a NoSQL database,
+      # thus there is no primary key for comments.
+      #
+      # Example:
+      #
+      #   <%= form(@post) do |f| %>
+      #     <% f.fields_for(:comments, :include_id => false) do |cf| %>
+      #       ...
+      #     <% end %>
+      #   <% end %>
+      #
       # === Customized form builders
       #
       # You can also build forms using a customized FormBuilder class. Subclass
@@ -332,7 +350,7 @@ module ActionView
 
         options[:html][:remote] = options.delete(:remote)
         options[:html][:authenticity_token] = options.delete(:authenticity_token)
-        
+
         builder = options[:parent_builder] = instantiate_builder(object_name, object, options, &proc)
         fields_for = fields_for(object_name, object, options, &proc)
         default_options = builder.multipart? ? { :multipart => true } : {}
@@ -1326,7 +1344,9 @@ module ActionView
         def fields_for_nested_model(name, object, options, block)
           object = convert_to_model(object)
 
-          options[:hidden_field_id] = object.persisted?
+          parent_include_id = self.options.fetch(:include_id, true)
+          include_id = options.fetch(:include_id, parent_include_id)
+          options[:hidden_field_id] = object.persisted? && include_id
           @template.fields_for(name, object, options, &block)
         end
 
diff --git a/actionpack/test/controller/caching_test.rb b/actionpack/test/controller/caching_test.rb
index cc393d3ef4..01f3e8f2b6 100644
--- a/actionpack/test/controller/caching_test.rb
+++ b/actionpack/test/controller/caching_test.rb
@@ -559,6 +559,11 @@ class ActionCacheTest < ActionController::TestCase
     assert_response 404
   end
 
+  def test_four_oh_four_renders_content
+    get :four_oh_four
+    assert_equal "404'd!", @response.body
+  end
+
   def test_simple_runtime_error_returns_500_for_multiple_requests
     get :simple_runtime_error
     assert_response 500
diff --git a/actionpack/test/dispatch/middleware_stack/middleware_test.rb b/actionpack/test/dispatch/middleware_stack/middleware_test.rb
new file mode 100644
index 0000000000..9607f026db
--- /dev/null
+++ b/actionpack/test/dispatch/middleware_stack/middleware_test.rb
@@ -0,0 +1,77 @@
+require 'abstract_unit'
+require 'action_dispatch/middleware/stack'
+
+module ActionDispatch
+  class MiddlewareStack
+    class MiddlewareTest < ActiveSupport::TestCase
+      class Omg; end
+
+      {
+        'concrete'  => Omg,
+        'anonymous' => Class.new
+      }.each do |name, klass|
+
+        define_method("test_#{name}_klass") do
+          mw = Middleware.new klass
+          assert_equal klass, mw.klass
+        end
+
+        define_method("test_#{name}_==") do
+          mw1 = Middleware.new klass
+          mw2 = Middleware.new klass
+          assert_equal mw1, mw2
+        end
+
+      end
+
+      def test_string_class
+        mw = Middleware.new Omg.name
+        assert_equal Omg, mw.klass
+      end
+
+      def test_double_equal_works_with_classes
+        k = Class.new
+        mw = Middleware.new k
+        assert_operator mw, :==, k
+
+        result = mw != Class.new
+        assert result, 'middleware should not equal other anon class'
+      end
+
+      def test_double_equal_works_with_strings
+        mw = Middleware.new Omg
+        assert_operator mw, :==, Omg.name
+      end
+
+      def test_double_equal_normalizes_strings
+        mw = Middleware.new Omg
+        assert_operator mw, :==, "::#{Omg.name}"
+      end
+
+      def test_middleware_loads_classnames_from_cache
+        mw = Class.new(Middleware) {
+          attr_accessor :classcache
+        }.new(Omg.name)
+
+        fake_cache    = { mw.name => Omg }
+        mw.classcache = fake_cache
+
+        assert_equal Omg, mw.klass
+
+        fake_cache[mw.name] = Middleware
+        assert_equal Middleware, mw.klass
+      end
+
+      def test_middleware_always_returns_class
+        mw = Class.new(Middleware) {
+          attr_accessor :classcache
+        }.new(Omg)
+
+        fake_cache    = { mw.name => Middleware }
+        mw.classcache = fake_cache
+
+        assert_equal Omg, mw.klass
+      end
+    end
+  end
+end
diff --git a/actionpack/test/template/asset_tag_helper_test.rb b/actionpack/test/template/asset_tag_helper_test.rb
index a1a6b5f1d0..1bf748af14 100644
--- a/actionpack/test/template/asset_tag_helper_test.rb
+++ b/actionpack/test/template/asset_tag_helper_test.rb
@@ -303,8 +303,17 @@ class AssetTagHelperTest < ActionView::TestCase
   end
 
   def test_custom_javascript_expansions_with_undefined_symbol
+    assert_raise(ArgumentError) { javascript_include_tag('first', :unknown, 'last') }
+  end
+
+  def test_custom_javascript_expansions_with_nil_value
     ActionView::Helpers::AssetTagHelper::register_javascript_expansion :monkey => nil
-    assert_raise(ArgumentError) { javascript_include_tag('first', :monkey, 'last') }
+    assert_dom_equal  %(<script src="/javascripts/first.js" type="text/javascript"></script>\n<script src="/javascripts/last.js" type="text/javascript"></script>), javascript_include_tag('first', :monkey, 'last')
+  end
+
+  def test_custom_javascript_expansions_with_empty_array_value
+    ActionView::Helpers::AssetTagHelper::register_javascript_expansion :monkey => []
+    assert_dom_equal  %(<script src="/javascripts/first.js" type="text/javascript"></script>\n<script src="/javascripts/last.js" type="text/javascript"></script>), javascript_include_tag('first', :monkey, 'last')
   end
 
   def test_custom_javascript_and_stylesheet_expansion_with_same_name
@@ -379,9 +388,18 @@ class AssetTagHelperTest < ActionView::TestCase
     assert_dom_equal  %(<link href="/stylesheets/london.css" media="screen" rel="stylesheet" type="text/css" />\n<link href="/stylesheets/wellington.css" media="screen" rel="stylesheet" type="text/css" />\n<link href="/stylesheets/amsterdam.css" media="screen" rel="stylesheet" type="text/css" />), stylesheet_link_tag('london', :cities)
   end
 
-  def test_custom_stylesheet_expansions_with_undefined_symbol
+  def test_custom_stylesheet_expansions_with_unknown_symbol
+    assert_raise(ArgumentError) { stylesheet_link_tag('first', :unknown, 'last') }
+  end
+
+  def test_custom_stylesheet_expansions_with_nil_value
     ActionView::Helpers::AssetTagHelper::register_stylesheet_expansion :monkey => nil
-    assert_raise(ArgumentError) { stylesheet_link_tag('first', :monkey, 'last') }
+    assert_dom_equal  %(<link href="/stylesheets/first.css" rel="stylesheet" type="text/css" media="screen" />\n<link href="/stylesheets/last.css" rel="stylesheet" type="text/css" media="screen" />), stylesheet_link_tag('first', :monkey, 'last')
+  end
+
+  def test_custom_stylesheet_expansions_with_empty_array_value
+    ActionView::Helpers::AssetTagHelper::register_stylesheet_expansion :monkey => []
+    assert_dom_equal  %(<link href="/stylesheets/first.css" rel="stylesheet" type="text/css" media="screen" />\n<link href="/stylesheets/last.css" rel="stylesheet" type="text/css" media="screen" />), stylesheet_link_tag('first', :monkey, 'last')
   end
 
   def test_registering_stylesheet_expansions_merges_with_existing_expansions
diff --git a/actionpack/test/template/date_helper_test.rb b/actionpack/test/template/date_helper_test.rb
index 3334f4ffb0..aca2fef170 100644
--- a/actionpack/test/template/date_helper_test.rb
+++ b/actionpack/test/template/date_helper_test.rb
@@ -1882,10 +1882,17 @@ class DateHelperTest < ActionView::TestCase
   end
 
   def test_datetime_select_defaults_to_time_zone_now_when_config_time_zone_is_set
-    time = stub(:year => 2004, :month => 6, :day => 15, :hour => 16, :min => 35, :sec => 0)
-    time_zone = mock()
-    time_zone.expects(:now).returns time
-    Time.zone_default = time_zone
+    # The love zone is UTC+0
+    mytz = Class.new(ActiveSupport::TimeZone) {
+      attr_accessor :now
+    }.create('tenderlove', 0)
+
+    now       = Time.mktime(2004, 6, 15, 16, 35, 0)
+    mytz.now  = now
+    Time.zone = mytz
+
+    assert_equal mytz, Time.zone
+
     @post = Post.new
 
     expected = %{<select id="post_updated_at_1i" name="post[updated_at(1i)]">\n}
@@ -1912,7 +1919,7 @@ class DateHelperTest < ActionView::TestCase
 
     assert_dom_equal expected, datetime_select("post", "updated_at")
   ensure
-    Time.zone_default = nil
+    Time.zone = nil
   end
 
   def test_datetime_select_with_html_options_within_fields_for
diff --git a/actionpack/test/template/form_helper_test.rb b/actionpack/test/template/form_helper_test.rb
index 31da26de7f..359b078466 100644
--- a/actionpack/test/template/form_helper_test.rb
+++ b/actionpack/test/template/form_helper_test.rb
@@ -1103,6 +1103,61 @@ class FormHelperTest < ActionView::TestCase
     assert_dom_equal expected, output_buffer
   end
 
+  def test_nested_fields_for_with_an_existing_record_on_a_nested_attributes_one_to_one_association_with_disabled_hidden_id
+    @post.author = Author.new(321)
+
+    form_for(@post) do |f|
+      concat f.text_field(:title)
+      concat f.fields_for(:author, :include_id => false) { |af|
+        af.text_field(:name)
+      }
+    end
+
+    expected = whole_form('/posts/123', 'edit_post_123', 'edit_post', :method => 'put') do
+      '<input name="post[title]" size="30" type="text" id="post_title" value="Hello World" />' +
+      '<input id="post_author_attributes_name" name="post[author_attributes][name]" size="30" type="text" value="author #321" />'
+    end
+
+    assert_dom_equal expected, output_buffer
+  end
+
+  def test_nested_fields_for_with_an_existing_record_on_a_nested_attributes_one_to_one_association_with_disabled_hidden_id_inherited
+    @post.author = Author.new(321)
+
+    form_for(@post, :include_id => false) do |f|
+      concat f.text_field(:title)
+      concat f.fields_for(:author) { |af|
+        af.text_field(:name)
+      }
+    end
+
+    expected = whole_form('/posts/123', 'edit_post_123', 'edit_post', :method => 'put') do
+      '<input name="post[title]" size="30" type="text" id="post_title" value="Hello World" />' +
+      '<input id="post_author_attributes_name" name="post[author_attributes][name]" size="30" type="text" value="author #321" />'
+    end
+
+    assert_dom_equal expected, output_buffer
+  end
+
+  def test_nested_fields_for_with_an_existing_record_on_a_nested_attributes_one_to_one_association_with_disabled_hidden_id_override
+    @post.author = Author.new(321)
+
+    form_for(@post, :include_id => false) do |f|
+      concat f.text_field(:title)
+      concat f.fields_for(:author, :include_id => true) { |af|
+        af.text_field(:name)
+      }
+    end
+
+    expected = whole_form('/posts/123', 'edit_post_123', 'edit_post', :method => 'put') do
+      '<input name="post[title]" size="30" type="text" id="post_title" value="Hello World" />' +
+      '<input id="post_author_attributes_name" name="post[author_attributes][name]" size="30" type="text" value="author #321" />' +
+      '<input id="post_author_attributes_id" name="post[author_attributes][id]" type="hidden" value="321" />'
+    end
+
+    assert_dom_equal expected, output_buffer
+  end
+
   def test_nested_fields_for_with_existing_records_on_a_nested_attributes_one_to_one_association_with_explicit_hidden_field_placement
     @post.author = Author.new(321)
 
@@ -1146,6 +1201,86 @@ class FormHelperTest < ActionView::TestCase
     assert_dom_equal expected, output_buffer
   end
 
+  def test_nested_fields_for_with_existing_records_on_a_nested_attributes_collection_association_with_disabled_hidden_id
+    @post.comments = Array.new(2) { |id| Comment.new(id + 1) }
+    @post.author = Author.new(321)
+
+    form_for(@post) do |f|
+      concat f.text_field(:title)
+      concat f.fields_for(:author) { |af|
+        concat af.text_field(:name)
+      }
+      @post.comments.each do |comment|
+        concat f.fields_for(:comments, comment, :include_id => false) { |cf|
+          concat cf.text_field(:name)
+        }
+      end
+    end
+
+    expected = whole_form('/posts/123', 'edit_post_123', 'edit_post', :method => 'put') do
+      '<input name="post[title]" size="30" type="text" id="post_title" value="Hello World" />' +
+      '<input id="post_author_attributes_name" name="post[author_attributes][name]" size="30" type="text" value="author #321" />' +
+      '<input id="post_author_attributes_id" name="post[author_attributes][id]" type="hidden" value="321" />' +
+      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" size="30" type="text" value="comment #1" />' +
+      '<input id="post_comments_attributes_1_name" name="post[comments_attributes][1][name]" size="30" type="text" value="comment #2" />'
+    end
+
+    assert_dom_equal expected, output_buffer
+  end
+
+  def test_nested_fields_for_with_existing_records_on_a_nested_attributes_collection_association_with_disabled_hidden_id_inherited
+    @post.comments = Array.new(2) { |id| Comment.new(id + 1) }
+    @post.author = Author.new(321)
+
+    form_for(@post, :include_id => false) do |f|
+      concat f.text_field(:title)
+      concat f.fields_for(:author) { |af|
+        concat af.text_field(:name)
+      }
+      @post.comments.each do |comment|
+        concat f.fields_for(:comments, comment) { |cf|
+          concat cf.text_field(:name)
+        }
+      end
+    end
+
+    expected = whole_form('/posts/123', 'edit_post_123', 'edit_post', :method => 'put') do
+      '<input name="post[title]" size="30" type="text" id="post_title" value="Hello World" />' +
+      '<input id="post_author_attributes_name" name="post[author_attributes][name]" size="30" type="text" value="author #321" />' +
+      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" size="30" type="text" value="comment #1" />' +
+      '<input id="post_comments_attributes_1_name" name="post[comments_attributes][1][name]" size="30" type="text" value="comment #2" />'
+    end
+
+    assert_dom_equal expected, output_buffer
+  end
+
+  def test_nested_fields_for_with_existing_records_on_a_nested_attributes_collection_association_with_disabled_hidden_id_override
+    @post.comments = Array.new(2) { |id| Comment.new(id + 1) }
+    @post.author = Author.new(321)
+
+    form_for(@post, :include_id => false) do |f|
+      concat f.text_field(:title)
+      concat f.fields_for(:author, :include_id => true) { |af|
+        concat af.text_field(:name)
+      }
+      @post.comments.each do |comment|
+        concat f.fields_for(:comments, comment) { |cf|
+          concat cf.text_field(:name)
+        }
+      end
+    end
+
+    expected = whole_form('/posts/123', 'edit_post_123', 'edit_post', :method => 'put') do
+      '<input name="post[title]" size="30" type="text" id="post_title" value="Hello World" />' +
+      '<input id="post_author_attributes_name" name="post[author_attributes][name]" size="30" type="text" value="author #321" />' +
+      '<input id="post_author_attributes_id" name="post[author_attributes][id]" type="hidden" value="321" />' +
+      '<input id="post_comments_attributes_0_name" name="post[comments_attributes][0][name]" size="30" type="text" value="comment #1" />' +
+      '<input id="post_comments_attributes_1_name" name="post[comments_attributes][1][name]" size="30" type="text" value="comment #2" />'
+    end
+
+    assert_dom_equal expected, output_buffer
+  end
+
   def test_nested_fields_for_with_existing_records_on_a_nested_attributes_collection_association_using_erb_and_inline_block
     @post.comments = Array.new(2) { |id| Comment.new(id + 1) }
 
diff --git a/activemodel/CHANGELOG b/activemodel/CHANGELOG
index 9dd5e03685..3082c7186a 100644
--- a/activemodel/CHANGELOG
+++ b/activemodel/CHANGELOG
@@ -2,6 +2,8 @@
 
 * Added ActiveModel::SecurePassword to encapsulate dead-simple password usage with BCrypt encryption and salting [DHH]
 
+* ActiveModel::AttributeMethods allows attributes to be defined on demand [Alexander Uvarov]
+
 
 *Rails 3.0.2 (unreleased)*
 
diff --git a/activemodel/lib/active_model/attribute_methods.rb b/activemodel/lib/active_model/attribute_methods.rb
index 8f3782eb48..2a99450a3d 100644
--- a/activemodel/lib/active_model/attribute_methods.rb
+++ b/activemodel/lib/active_model/attribute_methods.rb
@@ -260,30 +260,30 @@ module ActiveModel
       #     end
       #   end
       def define_attribute_methods(attr_names)
-        return if attribute_methods_generated?
-        attr_names.each do |attr_name|
-          attribute_method_matchers.each do |matcher|
-            unless instance_method_already_implemented?(matcher.method_name(attr_name))
-              generate_method = "define_method_#{matcher.prefix}attribute#{matcher.suffix}"
+        attr_names.each { |attr_name| define_attribute_method(attr_name) }
+      end
+
+      def define_attribute_method(attr_name)
+        attribute_method_matchers.each do |matcher|
+          unless instance_method_already_implemented?(matcher.method_name(attr_name))
+            generate_method = "define_method_#{matcher.prefix}attribute#{matcher.suffix}"
 
-              if respond_to?(generate_method)
-                send(generate_method, attr_name)
-              else
-                method_name = matcher.method_name(attr_name)
+            if respond_to?(generate_method)
+              send(generate_method, attr_name)
+            else
+              method_name = matcher.method_name(attr_name)
 
-                generated_attribute_methods.module_eval <<-STR, __FILE__, __LINE__ + 1
-                  if method_defined?('#{method_name}')
-                    undef :'#{method_name}'
-                  end
-                  define_method('#{method_name}') do |*args|
-                    send('#{matcher.method_missing_target}', '#{attr_name}', *args)
-                  end
-                STR
-              end
+              generated_attribute_methods.module_eval <<-STR, __FILE__, __LINE__ + 1
+                if method_defined?('#{method_name}')
+                  undef :'#{method_name}'
+                end
+                define_method('#{method_name}') do |*args|
+                  send('#{matcher.method_missing_target}', '#{attr_name}', *args)
+                end
+              STR
             end
           end
         end
-        @attribute_methods_generated = true
       end
 
       # Removes all the previously dynamically defined methods from the class
@@ -291,7 +291,6 @@ module ActiveModel
         generated_attribute_methods.module_eval do
           instance_methods.each { |m| undef_method(m) }
         end
-        @attribute_methods_generated = nil
       end
 
       # Returns true if the attribute methods defined have been generated.
@@ -303,11 +302,6 @@ module ActiveModel
         end
       end
 
-      # Returns true if the attribute methods defined have been generated.
-      def attribute_methods_generated?
-        @attribute_methods_generated ||= nil
-      end
-
       protected
         def instance_method_already_implemented?(method_name)
           method_defined?(method_name)
diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 5e3cf510b0..c2f0228785 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -295,8 +295,8 @@ module ActiveModel
       type = options.delete(:message) if options[:message].is_a?(Symbol)
 
       defaults = @base.class.lookup_ancestors.map do |klass|
-        [ :"#{@base.class.i18n_scope}.errors.models.#{klass.model_name.i18n_key}.attributes.#{attribute}.#{type}",
-          :"#{@base.class.i18n_scope}.errors.models.#{klass.model_name.i18n_key}.#{type}" ]
+        [ :"#{@base.class.i18n_scope}.errors.models.#{klass.model_name.underscore}.attributes.#{attribute}.#{type}",
+          :"#{@base.class.i18n_scope}.errors.models.#{klass.model_name.underscore}.#{type}" ]
       end
 
       defaults << options.delete(:message)
diff --git a/activemodel/lib/active_model/naming.rb b/activemodel/lib/active_model/naming.rb
index 3f430f94a6..eb9b847509 100644
--- a/activemodel/lib/active_model/naming.rb
+++ b/activemodel/lib/active_model/naming.rb
@@ -4,7 +4,7 @@ require 'active_support/core_ext/module/introspection'
 
 module ActiveModel
   class Name < String
-    attr_reader :singular, :plural, :element, :collection, :partial_path, :route_key, :param_key, :i18n_key
+    attr_reader :singular, :plural, :element, :collection, :partial_path, :route_key, :param_key
     alias_method :cache_key, :collection
 
     def initialize(klass, namespace = nil)
@@ -20,7 +20,6 @@ module ActiveModel
       @partial_path = "#{@collection}/#{@element}".freeze
       @param_key = (namespace ? _singularize(@unnamespaced) : @singular).freeze
       @route_key = (namespace ? ActiveSupport::Inflector.pluralize(@param_key) : @plural).freeze
-      @i18n_key = _singularize(self, '.').to_sym
     end
 
     # Transform the model name into a more humane format, using I18n. By default,
@@ -34,7 +33,7 @@ module ActiveModel
                            @klass.respond_to?(:i18n_scope)
 
       defaults = @klass.lookup_ancestors.map do |klass|
-        klass.model_name.i18n_key
+        klass.model_name.underscore.to_sym
       end
 
       defaults << options[:default] if options[:default]
@@ -45,10 +44,9 @@ module ActiveModel
     end
 
     private
-
-    def _singularize(string, replacement='_')
-      ActiveSupport::Inflector.underscore(string).tr('/', replacement)
-    end
+      def _singularize(str)
+        ActiveSupport::Inflector.underscore(str).tr('/', '_')
+      end
   end
 
   # == Active Model Naming
@@ -64,9 +62,6 @@ module ActiveModel
   #   BookCover.model_name        # => "BookCover"
   #   BookCover.model_name.human  # => "Book cover"
   #
-  #   BookCover.model_name.i18n_key              # => "book_cover"
-  #   BookModule::BookCover.model_name.i18n_key  # => "book_module.book_cover"
-  #
   # Providing the functionality that ActiveModel::Naming provides in your object
   # is required to pass the Active Model Lint test.  So either extending the provided
   # method below, or rolling your own is required.
diff --git a/activemodel/lib/active_model/translation.rb b/activemodel/lib/active_model/translation.rb
index 920a133159..dbb76244e4 100644
--- a/activemodel/lib/active_model/translation.rb
+++ b/activemodel/lib/active_model/translation.rb
@@ -44,7 +44,7 @@ module ActiveModel
     # Specify +options+ with additional translating options.
     def human_attribute_name(attribute, options = {})
       defaults = lookup_ancestors.map do |klass|
-        :"#{self.i18n_scope}.attributes.#{klass.model_name.i18n_key}.#{attribute}"
+        :"#{self.i18n_scope}.attributes.#{klass.model_name.underscore}.#{attribute}"
       end
 
       defaults << :"attributes.#{attribute}"
diff --git a/activemodel/test/cases/attribute_methods_test.rb b/activemodel/test/cases/attribute_methods_test.rb
index 422aa25668..b001adb35a 100644
--- a/activemodel/test/cases/attribute_methods_test.rb
+++ b/activemodel/test/cases/attribute_methods_test.rb
@@ -42,10 +42,16 @@ class AttributeMethodsTest < ActiveModel::TestCase
                      ModelWithAttributes2.send(:attribute_method_matchers)
   end
 
+  test '#define_attribute_method generates attribute method' do
+    ModelWithAttributes.define_attribute_method(:foo)
+
+    assert_respond_to ModelWithAttributes.new, :foo
+    assert_equal "value of foo", ModelWithAttributes.new.foo
+  end
+
   test '#define_attribute_methods generates attribute methods' do
     ModelWithAttributes.define_attribute_methods([:foo])
 
-    assert ModelWithAttributes.attribute_methods_generated?
     assert_respond_to ModelWithAttributes.new, :foo
     assert_equal "value of foo", ModelWithAttributes.new.foo
   end
@@ -53,7 +59,6 @@ class AttributeMethodsTest < ActiveModel::TestCase
   test '#define_attribute_methods generates attribute methods with spaces in their names' do
     ModelWithAttributesWithSpaces.define_attribute_methods([:'foo bar'])
   
-    assert ModelWithAttributesWithSpaces.attribute_methods_generated?
     assert_respond_to ModelWithAttributesWithSpaces.new, :'foo bar'
     assert_equal "value of foo bar", ModelWithAttributesWithSpaces.new.send(:'foo bar')
   end
@@ -69,7 +74,6 @@ class AttributeMethodsTest < ActiveModel::TestCase
     ModelWithAttributes.define_attribute_methods([:foo])
     ModelWithAttributes.undefine_attribute_methods
 
-    assert !ModelWithAttributes.attribute_methods_generated?
     assert !ModelWithAttributes.new.respond_to?(:foo)
     assert_raises(NoMethodError) { ModelWithAttributes.new.foo }
   end
diff --git a/activemodel/test/cases/translation_test.rb b/activemodel/test/cases/translation_test.rb
index c299d6eb5e..1b1d972d5c 100644
--- a/activemodel/test/cases/translation_test.rb
+++ b/activemodel/test/cases/translation_test.rb
@@ -49,6 +49,13 @@ class ActiveModelI18nTests < ActiveModel::TestCase
     assert_equal 'person name attribute', Child.human_attribute_name('name')
   end
 
+  def test_translated_model_attributes_with_attribute_matching_namespaced_model_name
+    I18n.backend.store_translations 'en', :activemodel => {:attributes => {:person => {:gender => 'person gender'}, :"person/gender" => {:attribute => 'person gender attribute'}}}
+
+    assert_equal 'person gender', Person.human_attribute_name('gender')
+    assert_equal 'person gender attribute', Person::Gender.human_attribute_name('attribute')
+  end
+
   def test_translated_model_names
     I18n.backend.store_translations 'en', :activemodel => {:models => {:person => 'person model'} }
     assert_equal 'person model', Person.model_name.human
diff --git a/activemodel/test/cases/validations/i18n_validation_test.rb b/activemodel/test/cases/validations/i18n_validation_test.rb
index 5cb7bff4e7..e9f0e430fe 100644
--- a/activemodel/test/cases/validations/i18n_validation_test.rb
+++ b/activemodel/test/cases/validations/i18n_validation_test.rb
@@ -55,14 +55,6 @@ class I18nValidationTest < ActiveModel::TestCase
     assert_equal ["Person's name not found"], @person.errors.full_messages
   end
 
-  def test_errors_full_messages_translates_human_attribute_name_for_model_in_module_attributes
-    I18n.backend.store_translations('en', :activemodel => {:attributes => {:person_module => {:person => {:name => "Person in Module's name"}}}})
-    person = PersonModule::Person.new
-    person.errors.add(:name, 'not found')
-    PersonModule::Person.expects(:human_attribute_name).with(:name, :default => 'Name').returns("Person in Module's name")
-    assert_equal ["Person in Module's name not found"], person.errors.full_messages
-  end
-
   def test_errors_full_messages_uses_format
     I18n.backend.store_translations('en', :errors => {:format => "Field %{attribute} %{message}"})
     @person.errors.add('name', 'empty')
@@ -371,15 +363,4 @@ class I18nValidationTest < ActiveModel::TestCase
     assert_equal ["I am a custom error"], @person.errors[:title]
   end
 
-  def test_model_with_module_i18n_scope
-      I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person_module => {:person => {:blank => 'generic blank'}}}}}
-      PersonModule::Person.validates_presence_of :title
-      person = PersonModule::Person.new
-      person.valid?
-      assert_equal ['generic blank'], person.errors[:title]
-
-      I18n.backend.store_translations 'en', :activemodel => {:errors => {:models => {:person_module => {:person => {:attributes => {:title => {:blank => 'title cannot be blank'}}}}}}}
-      person.valid?
-      assert_equal ['title cannot be blank'], person.errors[:title]
-  end
 end
diff --git a/activemodel/test/models/person.rb b/activemodel/test/models/person.rb
index eb84f7a27d..e896e90f98 100644
--- a/activemodel/test/models/person.rb
+++ b/activemodel/test/models/person.rb
@@ -9,10 +9,9 @@ class Person
   end
 end
 
-class Child < Person
+class Person::Gender
+  extend ActiveModel::Translation
 end
 
-module PersonModule
-  class Person < ::Person
-  end
+class Child < Person
 end
diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 1f343f690c..8b4e9a34cb 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,17 @@
 *Rails 3.1.0 (unreleased)*
 
+* The configuration for the current database connection is now accessible via
+  ActiveRecord::Base.connection_config. [fxn]
+
+* limits and offsets are removed from COUNT queries unless both are supplied.
+  For example:
+
+    People.limit(1).count           # => 'SELECT COUNT(*) FROM people'
+    People.offset(1).count          # => 'SELECT COUNT(*) FROM people'
+    People.limit(1).offset(1).count # => 'SELECT COUNT(*) FROM people LIMIT 1 OFFSET 1'
+
+  [lighthouse #6262]
+
 * ActiveRecord::Associations::AssociationProxy has been split. There is now an Association class
   (and subclasses) which are responsible for operating on associations, and then a separate,
   thin wrapper called CollectionProxy, which proxies collection associations.
diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb
index 0777f85869..59cf42a377 100644
--- a/activerecord/lib/active_record.rb
+++ b/activerecord/lib/active_record.rb
@@ -43,7 +43,6 @@ module ActiveRecord
     autoload :ConnectionNotEstablished, 'active_record/errors'
 
     autoload :Aggregations
-    autoload :AssociationPreload
     autoload :Associations
     autoload :AttributeMethods
     autoload :AutosaveAssociation
diff --git a/activerecord/lib/active_record/association_preload.rb b/activerecord/lib/active_record/association_preload.rb
deleted file mode 100644
index a34a73cf5d..0000000000
--- a/activerecord/lib/active_record/association_preload.rb
+++ /dev/null
@@ -1,433 +0,0 @@
-require 'active_support/core_ext/array/wrap'
-require 'active_support/core_ext/enumerable'
-
-module ActiveRecord
-  # See ActiveRecord::AssociationPreload::ClassMethods for documentation.
-  module AssociationPreload #:nodoc:
-    extend ActiveSupport::Concern
-
-    # Implements the details of eager loading of Active Record associations.
-    # Application developers should not use this module directly.
-    #
-    # <tt>ActiveRecord::Base</tt> is extended with this module. The source code in
-    # <tt>ActiveRecord::Base</tt> references methods defined in this module.
-    #
-    # Note that 'eager loading' and 'preloading' are actually the same thing.
-    # However, there are two different eager loading strategies.
-    #
-    # The first one is by using table joins. This was only strategy available
-    # prior to Rails 2.1. Suppose that you have an Author model with columns
-    # 'name' and 'age', and a Book model with columns 'name' and 'sales'. Using
-    # this strategy, Active Record would try to retrieve all data for an author
-    # and all of its books via a single query:
-    #
-    #   SELECT * FROM authors
-    #   LEFT OUTER JOIN books ON authors.id = books.id
-    #   WHERE authors.name = 'Ken Akamatsu'
-    #
-    # However, this could result in many rows that contain redundant data. After
-    # having received the first row, we already have enough data to instantiate
-    # the Author object. In all subsequent rows, only the data for the joined
-    # 'books' table is useful; the joined 'authors' data is just redundant, and
-    # processing this redundant data takes memory and CPU time. The problem
-    # quickly becomes worse and worse as the level of eager loading increases
-    # (i.e. if Active Record is to eager load the associations' associations as
-    # well).
-    #
-    # The second strategy is to use multiple database queries, one for each
-    # level of association. Since Rails 2.1, this is the default strategy. In
-    # situations where a table join is necessary (e.g. when the +:conditions+
-    # option references an association's column), it will fallback to the table
-    # join strategy.
-    #
-    # See also ActiveRecord::Associations::ClassMethods, which explains eager
-    # loading in a more high-level (application developer-friendly) manner.
-    module ClassMethods
-      protected
-
-      # Eager loads the named associations for the given Active Record record(s).
-      #
-      # In this description, 'association name' shall refer to the name passed
-      # to an association creation method. For example, a model that specifies
-      # <tt>belongs_to :author</tt>, <tt>has_many :buyers</tt> has association
-      # names +:author+ and +:buyers+.
-      #
-      # == Parameters
-      # +records+ is an array of ActiveRecord::Base. This array needs not be flat,
-      # i.e. +records+ itself may also contain arrays of records. In any case,
-      # +preload_associations+ will preload the all associations records by
-      # flattening +records+.
-      #
-      # +associations+ specifies one or more associations that you want to
-      # preload. It may be:
-      # - a Symbol or a String which specifies a single association name. For
-      #   example, specifying +:books+ allows this method to preload all books
-      #   for an Author.
-      # - an Array which specifies multiple association names. This array
-      #   is processed recursively. For example, specifying <tt>[:avatar, :books]</tt>
-      #   allows this method to preload an author's avatar as well as all of his
-      #   books.
-      # - a Hash which specifies multiple association names, as well as
-      #   association names for the to-be-preloaded association objects. For
-      #   example, specifying <tt>{ :author => :avatar }</tt> will preload a
-      #   book's author, as well as that author's avatar.
-      #
-      # +:associations+ has the same format as the +:include+ option for
-      # <tt>ActiveRecord::Base.find</tt>. So +associations+ could look like this:
-      #
-      #   :books
-      #   [ :books, :author ]
-      #   { :author => :avatar }
-      #   [ :books, { :author => :avatar } ]
-      #
-      # +preload_options+ contains options that will be passed to ActiveRecord::Base#find
-      # (which is called under the hood for preloading records). But it is passed
-      # only one level deep in the +associations+ argument, i.e. it's not passed
-      # to the child associations when +associations+ is a Hash.
-      def preload_associations(records, associations, preload_options={})
-        records = Array.wrap(records).compact.uniq
-        return if records.empty?
-        case associations
-        when Array then associations.each {|association| preload_associations(records, association, preload_options)}
-        when Symbol, String then preload_one_association(records, associations.to_sym, preload_options)
-        when Hash then
-          associations.each do |parent, child|
-            raise "parent must be an association name" unless parent.is_a?(String) || parent.is_a?(Symbol)
-            preload_associations(records, parent, preload_options)
-            reflection = reflections[parent]
-            parents = records.sum { |record| Array.wrap(record.send(reflection.name)) }
-            unless parents.empty?
-              parents.first.class.preload_associations(parents, child)
-            end
-          end
-        end
-      end
-
-      private
-
-      # Preloads a specific named association for the given records. This is
-      # called by +preload_associations+ as its base case.
-      def preload_one_association(records, association, preload_options={})
-        class_to_reflection = {}
-        # Not all records have the same class, so group then preload
-        # group on the reflection itself so that if various subclass share the same association then
-        # we do not split them unnecessarily
-        records.group_by { |record| class_to_reflection[record.class] ||= record.class.reflections[association]}.each do |reflection, _records|
-          raise ConfigurationError, "Association named '#{ association }' was not found; perhaps you misspelled it?" unless reflection
-
-          # 'reflection.macro' can return 'belongs_to', 'has_many', etc. Thus,
-          # the following could call 'preload_belongs_to_association',
-          # 'preload_has_many_association', etc.
-          send("preload_#{reflection.macro}_association", _records, reflection, preload_options)
-        end
-      end
-
-      def add_preloaded_records_to_collection(parent_records, reflection_name, associated_record)
-        parent_records.each do |parent_record|
-          association = parent_record.association(reflection_name)
-          association.loaded!
-          association.target.concat(Array.wrap(associated_record))
-          association.set_inverse_instance(associated_record)
-        end
-      end
-
-      def add_preloaded_record_to_collection(parent_records, reflection_name, associated_record)
-        parent_records.each do |parent_record|
-          parent_record.association(reflection_name).target = associated_record
-        end
-      end
-
-      def set_association_collection_records(id_to_parent_map, reflection_name, associated_records, key)
-        associated_records.each do |associated_record|
-          parent_records = id_to_parent_map[associated_record[key].to_s]
-          add_preloaded_records_to_collection(parent_records, reflection_name, associated_record)
-        end
-      end
-
-      def set_association_single_records(id_to_record_map, reflection_name, associated_records, key)
-        seen_keys = {}
-        associated_records.each do |associated_record|
-          seen_key = associated_record[key].to_s
-
-          #this is a has_one or belongs_to: there should only be one record.
-          #Unfortunately we can't (in portable way) ask the database for
-          #'all records where foo_id in (x,y,z), but please
-          # only one row per distinct foo_id' so this where we enforce that
-          next if seen_keys.key? seen_key
-
-          seen_keys[seen_key] = true
-          mapped_records = id_to_record_map[seen_key]
-          mapped_records.each do |mapped_record|
-            association_proxy = mapped_record.association(reflection_name)
-            association_proxy.target = associated_record
-            association_proxy.send(:set_inverse_instance, associated_record)
-          end
-        end
-
-        id_to_record_map.each do |id, records|
-          next if seen_keys.include?(id)
-          add_preloaded_record_to_collection(records, reflection_name, nil)
-        end
-      end
-
-      # Given a collection of Active Record objects, constructs a Hash which maps
-      # the objects' IDs to the relevant objects. Returns a 2-tuple
-      # <tt>(id_to_record_map, ids)</tt> where +id_to_record_map+ is the Hash,
-      # and +ids+ is an Array of record IDs.
-      def construct_id_map(records, primary_key=nil)
-        records.group_by do |record|
-          primary_key ||= record.class.primary_key
-          record[primary_key].to_s
-        end
-      end
-
-      def preload_has_and_belongs_to_many_association(records, reflection, preload_options={})
-
-        left = reflection.klass.arel_table
-
-        id_to_record_map = construct_id_map(records)
-
-        records.each { |record| record.association(reflection.name).loaded! }
-        options = reflection.options
-
-        right = Arel::Table.new(options[:join_table]).alias('t0')
-
-        join_condition = left[reflection.klass.primary_key].eq(
-          right[reflection.association_foreign_key])
-
-        join = left.create_join(right, left.create_on(join_condition))
-        select = [
-          # FIXME: options[:select] is always nil in the tests.  Do we really
-          # need it?
-          options[:select] || left[Arel.star],
-          right[reflection.foreign_key].as(
-            Arel.sql('the_parent_record_id'))
-        ]
-
-        associated_records_proxy = reflection.klass.unscoped.
-            includes(options[:include]).
-            order(options[:order])
-
-        associated_records_proxy.joins_values = [join]
-        associated_records_proxy.select_values = select
-
-        custom_conditions = append_conditions(reflection, preload_options)
-
-        klass = associated_records_proxy.klass
-
-        associated_records(id_to_record_map.keys) { |some_ids|
-          method     = in_or_equal(some_ids)
-          conditions = right.create_and(
-            [right[reflection.foreign_key].send(*method)] +
-            custom_conditions)
-
-          relation = associated_records_proxy.where(conditions)
-          klass.connection.select_all(relation.arel.to_sql, 'SQL', relation.bind_values)
-        }.map! { |row|
-          parent_records = id_to_record_map[row['the_parent_record_id'].to_s]
-          associated_record = klass.instantiate row
-          add_preloaded_records_to_collection(
-            parent_records, reflection.name, associated_record)
-          associated_record
-        }
-      end
-
-      def preload_has_one_association(records, reflection, preload_options={})
-        return if records.first.association(reflection.name).loaded?
-        id_to_record_map = construct_id_map(records, reflection.options[:primary_key])
-        options = reflection.options
-
-        add_preloaded_record_to_collection(records, reflection.name, nil)
-
-        if options[:through]
-          through_records = preload_through_records(records, reflection, options[:through])
-
-          unless through_records.empty?
-            through_reflection = reflections[options[:through]]
-            through_primary_key = through_reflection.foreign_key
-            source = reflection.source_reflection.name
-            through_records.first.class.preload_associations(through_records, source)
-            if through_reflection.macro == :belongs_to
-              id_to_record_map    = construct_id_map(records, through_primary_key)
-              through_primary_key = through_reflection.klass.primary_key
-            end
-
-            through_records.each do |through_record|
-              add_preloaded_record_to_collection(id_to_record_map[through_record[through_primary_key].to_s],
-                                                 reflection.name, through_record.send(source))
-            end
-          end
-        else
-          set_association_single_records(id_to_record_map, reflection.name, find_associated_records(id_to_record_map.keys, reflection, preload_options), reflection.foreign_key)
-        end
-      end
-
-      def preload_has_many_association(records, reflection, preload_options={})
-        return if records.first.send(reflection.name).loaded?
-        options = reflection.options
-
-        foreign_key = reflection.through_reflection_foreign_key
-        id_to_record_map = construct_id_map(records, foreign_key || reflection.options[:primary_key])
-        records.each { |record| record.association(reflection.name).loaded! }
-
-        if options[:through]
-          through_records = preload_through_records(records, reflection, options[:through])
-          unless through_records.empty?
-            source = reflection.source_reflection.name
-            through_records.first.class.preload_associations(through_records, source, options)
-            through_records.each do |through_record|
-              through_record_id = through_record[reflection.through_reflection_primary_key].to_s
-              add_preloaded_records_to_collection(id_to_record_map[through_record_id], reflection.name, through_record.send(source))
-            end
-            records.each { |record| record.send(reflection.name).target.uniq! } if options[:uniq]
-          end
-
-        else
-          set_association_collection_records(id_to_record_map, reflection.name, find_associated_records(id_to_record_map.keys, reflection, preload_options),
-                                             reflection.foreign_key)
-        end
-      end
-
-      def preload_through_records(records, reflection, through_association)
-        if reflection.options[:source_type]
-          interface = reflection.source_reflection.foreign_type
-          preload_options = {:conditions => ["#{connection.quote_column_name interface} = ?", reflection.options[:source_type]]}
-
-          records.compact!
-          records.first.class.preload_associations(records, through_association, preload_options)
-
-          # Dont cache the association - we would only be caching a subset
-          records.map { |record|
-            proxy = record.association(through_association)
-
-            if proxy.respond_to?(:target)
-              Array.wrap(proxy.target).tap { proxy.reset }
-            else # this is a has_one :through reflection
-              [proxy].compact
-            end
-          }.flatten(1)
-        else
-          options = {}
-          options[:include] = reflection.options[:include] || reflection.options[:source] if reflection.options[:conditions]
-          options[:order] = reflection.options[:order]
-          options[:conditions] = reflection.options[:conditions]
-          records.first.class.preload_associations(records, through_association, options)
-
-          records.map { |record|
-            Array.wrap(record.send(through_association))
-          }.flatten(1)
-        end
-      end
-
-      def preload_belongs_to_association(records, reflection, preload_options={})
-        return if records.first.association(reflection.name).loaded?
-        options = reflection.options
-
-        klasses_and_ids = {}
-
-        if options[:polymorphic]
-          # Construct a mapping from klass to a list of ids to load and a mapping of those ids back
-          # to their parent_records
-          records.each do |record|
-            if klass = record.send(reflection.foreign_type)
-              klass_id = record.send(reflection.foreign_key)
-              if klass_id
-                id_map = klasses_and_ids[klass.constantize] ||= {}
-                (id_map[klass_id.to_s] ||= []) << record
-              end
-            end
-          end
-        else
-          id_map = records.group_by do |record|
-            key = record.send(reflection.foreign_key)
-            key && key.to_s
-          end
-          klasses_and_ids[reflection.klass] = id_map unless id_map.empty?
-        end
-
-        klasses_and_ids.each do |klass, _id_map|
-          primary_key = (reflection.options[:primary_key] || klass.primary_key).to_s
-          keys        = _id_map.keys.compact
-
-          unless keys.empty?
-            table       = klass.arel_table
-            method      = in_or_equal(keys)
-            conditions  = table[primary_key].send(*method)
-
-            custom_conditions = append_conditions(reflection, preload_options)
-            conditions = custom_conditions.inject(conditions) do |ast, cond|
-              ast.and cond
-            end
-
-            associated_records = klass.unscoped.where(conditions).apply_finder_options(options.slice(:include, :select, :joins, :order)).to_a
-          else
-            associated_records = []
-          end
-
-          set_association_single_records(_id_map, reflection.name, associated_records, primary_key)
-        end
-      end
-
-      def find_associated_records(ids, reflection, preload_options)
-        options    = reflection.options
-        table      = reflection.klass.arel_table
-
-        conditions = []
-
-        key = reflection.foreign_key
-
-        if interface = reflection.options[:as]
-          key = "#{interface}_id"
-          conditions << table["#{interface}_type"].eq(base_class.sti_name)
-        end
-
-        conditions.concat append_conditions(reflection, preload_options)
-
-        find_options = {
-          :select => preload_options[:select] || options[:select] || table[Arel.star],
-          :include => preload_options[:include] || options[:include],
-          :joins => options[:joins],
-          :group => preload_options[:group] || options[:group],
-          :order => preload_options[:order] || options[:order]
-        }
-
-        associated_records(ids) do |some_ids|
-          method = in_or_equal(some_ids)
-          where = table.create_and(conditions + [table[key].send(*method)])
-
-          reflection.klass.scoped.apply_finder_options(find_options.merge(:conditions => where)).to_a
-        end
-      end
-
-      def process_conditions(conditions, klass = self)
-        if conditions.respond_to?(:to_proc)
-          conditions = instance_eval(&conditions)
-        end
-
-        klass.send(:sanitize_sql, conditions)
-      end
-
-      def append_conditions(reflection, preload_options)
-        [
-          ('(' + process_conditions(reflection.options[:conditions], reflection.klass) + ')' if reflection.options[:conditions]),
-          ('(' + process_conditions(preload_options[:conditions]) + ')' if preload_options[:conditions]),
-        ].compact.map { |x| Arel.sql x }
-      end
-
-      def in_or_equal(ids)
-        ids.length == 1 ? ['eq', ids.first] : ['in', ids]
-      end
-
-      # Some databases impose a limit on the number of ids in a list (in Oracle its 1000)
-      # Make several smaller queries if necessary or make one query if the adapter supports it
-      def associated_records(ids)
-        in_clause_length = connection.in_clause_length || ids.size
-        records = []
-        ids.each_slice(in_clause_length) do |some_ids|
-          records.concat yield(some_ids)
-        end
-        records
-      end
-    end
-  end
-end
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index e0b4db498d..e91cbd7f33 100644
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -5,7 +5,6 @@ require 'active_support/core_ext/object/blank'
 require 'active_support/core_ext/string/conversions'
 require 'active_support/core_ext/module/remove_method'
 require 'active_support/core_ext/class/attribute'
-require 'active_record/associations/class_methods/join_dependency'
 
 module ActiveRecord
   class InverseOfAssociationNotFoundError < ActiveRecordError #:nodoc:
@@ -143,6 +142,9 @@ module ActiveRecord
       autoload :HasAndBelongsToMany, 'active_record/associations/builder/has_and_belongs_to_many'
     end
 
+    autoload :Preloader,      'active_record/associations/preloader'
+    autoload :JoinDependency, 'active_record/associations/join_dependency'
+
     # Clears out the association cache.
     def clear_association_cache #:nodoc:
       @association_cache.clear if persisted?
diff --git a/activerecord/lib/active_record/associations/association.rb b/activerecord/lib/active_record/associations/association.rb
index 81904afe3a..25b4b9d90d 100644
--- a/activerecord/lib/active_record/associations/association.rb
+++ b/activerecord/lib/active_record/associations/association.rb
@@ -191,8 +191,8 @@ module ActiveRecord
           else
             attributes[reflection.foreign_key] = owner[reflection.active_record_primary_key]
 
-            if options[:as]
-              attributes["#{options[:as]}_type"] = owner.class.base_class.name
+            if reflection.options[:as]
+              attributes[reflection.type] = owner.class.base_class.name
             end
           end
           attributes
diff --git a/activerecord/lib/active_record/associations/class_methods/join_dependency.rb b/activerecord/lib/active_record/associations/class_methods/join_dependency.rb
deleted file mode 100644
index b711ff35ca..0000000000
--- a/activerecord/lib/active_record/associations/class_methods/join_dependency.rb
+++ /dev/null
@@ -1,233 +0,0 @@
-require 'active_record/associations/class_methods/join_dependency/join_part'
-require 'active_record/associations/class_methods/join_dependency/join_base'
-require 'active_record/associations/class_methods/join_dependency/join_association'
-
-module ActiveRecord
-  module Associations
-    module ClassMethods
-      class JoinDependency # :nodoc:
-        attr_reader :join_parts, :reflections, :table_aliases, :active_record
-
-        def initialize(base, associations, joins)
-          @active_record         = base
-          @table_joins           = joins
-          @join_parts            = [JoinBase.new(base)]
-          @associations          = {}
-          @reflections           = []
-          @table_aliases         = Hash.new do |h,name|
-            h[name] = count_aliases_from_table_joins(name.downcase)
-          end
-          @table_aliases[base.table_name] = 1
-          build(associations)
-        end
-
-        def graft(*associations)
-          associations.each do |association|
-            join_associations.detect {|a| association == a} ||
-              build(association.reflection.name, association.find_parent_in(self) || join_base, association.join_type)
-          end
-          self
-        end
-
-        def join_associations
-          join_parts.last(join_parts.length - 1)
-        end
-
-        def join_base
-          join_parts.first
-        end
-
-        def columns
-          join_parts.collect { |join_part|
-            table = join_part.aliased_table
-            join_part.column_names_with_alias.collect{ |column_name, aliased_name|
-              table[column_name].as Arel.sql(aliased_name)
-            }
-          }.flatten
-        end
-
-        def count_aliases_from_table_joins(name)
-          return 0 if Arel::Table === @table_joins
-
-          # quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase
-          quoted_name = active_record.connection.quote_table_name(name).downcase
-
-          @table_joins.map { |join|
-            # Table names + table aliases
-            join.left.downcase.scan(
-              /join(?:\s+\w+)?\s+(\S+\s+)?#{quoted_name}\son/
-            ).size
-          }.sum
-        end
-
-        def instantiate(rows)
-          primary_key = join_base.aliased_primary_key
-          parents = {}
-
-          records = rows.map { |model|
-            primary_id = model[primary_key]
-            parent = parents[primary_id] ||= join_base.instantiate(model)
-            construct(parent, @associations, join_associations, model)
-            parent
-          }.uniq
-
-          remove_duplicate_results!(active_record, records, @associations)
-          records
-        end
-
-        def remove_duplicate_results!(base, records, associations)
-          case associations
-          when Symbol, String
-            reflection = base.reflections[associations]
-            remove_uniq_by_reflection(reflection, records)
-          when Array
-            associations.each do |association|
-              remove_duplicate_results!(base, records, association)
-            end
-          when Hash
-            associations.keys.each do |name|
-              reflection = base.reflections[name]
-              remove_uniq_by_reflection(reflection, records)
-
-              parent_records = []
-              records.each do |record|
-                if descendant = record.send(reflection.name)
-                  if reflection.collection?
-                    parent_records.concat descendant.target.uniq
-                  else
-                    parent_records << descendant
-                  end
-                end
-              end
-
-              remove_duplicate_results!(reflection.klass, parent_records, associations[name]) unless parent_records.empty?
-            end
-          end
-        end
-
-        protected
-
-        def cache_joined_association(association)
-          associations = []
-          parent = association.parent
-          while parent != join_base
-            associations.unshift(parent.reflection.name)
-            parent = parent.parent
-          end
-          ref = @associations
-          associations.each do |key|
-            ref = ref[key]
-          end
-          ref[association.reflection.name] ||= {}
-        end
-
-        def build(associations, parent = nil, join_type = Arel::InnerJoin)
-          parent ||= join_parts.last
-          case associations
-          when Symbol, String
-            reflection = parent.reflections[associations.to_s.intern] or
-            raise ConfigurationError, "Association named '#{ associations }' was not found; perhaps you misspelled it?"
-            unless join_association = find_join_association(reflection, parent)
-              @reflections << reflection
-              join_association = build_join_association(reflection, parent)
-              join_association.join_type = join_type
-              @join_parts << join_association
-              cache_joined_association(join_association)
-            end
-            join_association
-          when Array
-            associations.each do |association|
-              build(association, parent, join_type)
-            end
-          when Hash
-            associations.keys.sort_by { |a| a.to_s }.each do |name|
-              join_association = build(name, parent, join_type)
-              build(associations[name], join_association, join_type)
-            end
-          else
-            raise ConfigurationError, associations.inspect
-          end
-        end
-
-        def find_join_association(name_or_reflection, parent)
-          if String === name_or_reflection
-            name_or_reflection = name_or_reflection.to_sym
-          end
-
-          join_associations.detect { |j|
-            j.reflection == name_or_reflection && j.parent == parent
-          }
-        end
-
-        def remove_uniq_by_reflection(reflection, records)
-          if reflection && reflection.collection?
-            records.each { |record| record.send(reflection.name).target.uniq! }
-          end
-        end
-
-        def build_join_association(reflection, parent)
-          JoinAssociation.new(reflection, self, parent)
-        end
-
-        def construct(parent, associations, join_parts, row)
-          case associations
-          when Symbol, String
-            name = associations.to_s
-
-            join_part = join_parts.detect { |j|
-              j.reflection.name.to_s == name &&
-                j.parent_table_name == parent.class.table_name }
-
-              raise(ConfigurationError, "No such association") unless join_part
-
-              join_parts.delete(join_part)
-              construct_association(parent, join_part, row)
-          when Array
-            associations.each do |association|
-              construct(parent, association, join_parts, row)
-            end
-          when Hash
-            associations.sort_by { |k,_| k.to_s }.each do |association_name, assoc|
-              association = construct(parent, association_name, join_parts, row)
-              construct(association, assoc, join_parts, row) if association
-            end
-          else
-            raise ConfigurationError, associations.inspect
-          end
-        end
-
-        def construct_association(record, join_part, row)
-          return if record.id.to_s != join_part.parent.record_id(row).to_s
-
-          macro = join_part.reflection.macro
-          if macro == :has_one
-            return if record.association_cache.key?(join_part.reflection.name)
-            association = join_part.instantiate(row) unless row[join_part.aliased_primary_key].nil?
-            set_target_and_inverse(join_part, association, record)
-          else
-            return if row[join_part.aliased_primary_key].nil?
-            association = join_part.instantiate(row)
-            case macro
-            when :has_many, :has_and_belongs_to_many
-              other = record.association(join_part.reflection.name)
-              other.loaded!
-              other.target.push(association)
-              other.set_inverse_instance(association)
-            when :belongs_to
-              set_target_and_inverse(join_part, association, record)
-            else
-              raise ConfigurationError, "unknown macro: #{join_part.reflection.macro}"
-            end
-          end
-          association
-        end
-
-        def set_target_and_inverse(join_part, association, record)
-          other = record.association(join_part.reflection.name)
-          other.target = association
-          other.set_inverse_instance(association)
-        end
-      end
-    end
-  end
-end
diff --git a/activerecord/lib/active_record/associations/class_methods/join_dependency/join_association.rb b/activerecord/lib/active_record/associations/class_methods/join_dependency/join_association.rb
deleted file mode 100644
index aaa475109e..0000000000
--- a/activerecord/lib/active_record/associations/class_methods/join_dependency/join_association.rb
+++ /dev/null
@@ -1,281 +0,0 @@
-module ActiveRecord
-  module Associations
-    module ClassMethods
-      class JoinDependency # :nodoc:
-        class JoinAssociation < JoinPart # :nodoc:
-          # The reflection of the association represented
-          attr_reader :reflection
-
-          # The JoinDependency object which this JoinAssociation exists within. This is mainly
-          # relevant for generating aliases which do not conflict with other joins which are
-          # part of the query.
-          attr_reader :join_dependency
-
-          # A JoinBase instance representing the active record we are joining onto.
-          # (So in Author.has_many :posts, the Author would be that base record.)
-          attr_reader :parent
-
-          # What type of join will be generated, either Arel::InnerJoin (default) or Arel::OuterJoin
-          attr_accessor :join_type
-
-          # These implement abstract methods from the superclass
-          attr_reader :aliased_prefix, :aliased_table_name
-
-          delegate :options, :through_reflection, :source_reflection, :to => :reflection
-          delegate :table, :table_name, :to => :parent, :prefix => :parent
-
-          def initialize(reflection, join_dependency, parent = nil)
-            reflection.check_validity!
-
-            if reflection.options[:polymorphic]
-              raise EagerLoadPolymorphicError.new(reflection)
-            end
-
-            super(reflection.klass)
-
-            @reflection      = reflection
-            @join_dependency = join_dependency
-            @parent          = parent
-            @join_type       = Arel::InnerJoin
-            @aliased_prefix  = "t#{ join_dependency.join_parts.size }"
-
-            # This must be done eagerly upon initialisation because the alias which is produced
-            # depends on the state of the join dependency, but we want it to work the same way
-            # every time.
-            allocate_aliases
-            @table = Arel::Table.new(
-              table_name, :as => aliased_table_name, :engine => arel_engine
-            )
-          end
-
-          def ==(other)
-            other.class == self.class &&
-              other.reflection == reflection &&
-              other.parent == parent
-          end
-
-          def find_parent_in(other_join_dependency)
-            other_join_dependency.join_parts.detect do |join_part|
-              parent == join_part
-            end
-          end
-
-          def join_to(relation)
-            send("join_#{reflection.macro}_to", relation)
-          end
-
-          def join_relation(joining_relation)
-            self.join_type = Arel::OuterJoin
-            joining_relation.joins(self)
-          end
-
-          attr_reader :table
-          # More semantic name given we are talking about associations
-          alias_method :target_table, :table
-
-          protected
-
-          def aliased_table_name_for(name, suffix = nil)
-            aliases = @join_dependency.table_aliases
-
-            if aliases[name] != 0 # We need an alias
-              connection = active_record.connection
-
-              name = connection.table_alias_for "#{pluralize(reflection.name)}_#{parent_table_name}#{suffix}"
-              aliases[name] += 1
-              name = name[0, connection.table_alias_length-3] + "_#{aliases[name]}" if aliases[name] > 1
-            else
-              aliases[name] += 1
-            end
-
-            name
-          end
-
-          def pluralize(table_name)
-            ActiveRecord::Base.pluralize_table_names ? table_name.to_s.pluralize : table_name
-          end
-
-          private
-
-          def allocate_aliases
-            @aliased_table_name = aliased_table_name_for(table_name)
-
-            if reflection.macro == :has_and_belongs_to_many
-              @aliased_join_table_name = aliased_table_name_for(reflection.options[:join_table], "_join")
-            elsif [:has_many, :has_one].include?(reflection.macro) && reflection.options[:through]
-              @aliased_join_table_name = aliased_table_name_for(reflection.through_reflection.klass.table_name, "_join")
-            end
-          end
-
-          def process_conditions(conditions, table_name)
-            if conditions.respond_to?(:to_proc)
-              conditions = instance_eval(&conditions)
-            end
-
-            Arel.sql(sanitize_sql(conditions, table_name))
-          end
-
-          def sanitize_sql(condition, table_name)
-            active_record.send(:sanitize_sql, condition, table_name)
-          end
-
-          def join_target_table(relation, condition)
-            conditions = [condition]
-
-            # If the target table is an STI model then we must be sure to only include records of
-            # its type and its sub-types.
-            unless active_record.descends_from_active_record?
-              sti_column    = target_table[active_record.inheritance_column]
-              subclasses    = active_record.descendants
-              sti_condition = sti_column.eq(active_record.sti_name)
-
-              conditions << subclasses.inject(sti_condition) { |attr,subclass|
-                attr.or(sti_column.eq(subclass.sti_name))
-              }
-            end
-
-            # If the reflection has conditions, add them
-            if options[:conditions]
-              conditions << process_conditions(options[:conditions], aliased_table_name)
-            end
-
-            ands = relation.create_and(conditions)
-
-            join = relation.create_join(
-              target_table,
-              relation.create_on(ands),
-              join_type)
-
-            relation.from join
-          end
-
-          def join_has_and_belongs_to_many_to(relation)
-            join_table = Arel::Table.new(
-              options[:join_table]
-            ).alias(@aliased_join_table_name)
-
-            fk       = options[:foreign_key]             || reflection.active_record.to_s.foreign_key
-            klass_fk = options[:association_foreign_key] || reflection.klass.to_s.foreign_key
-
-            relation = relation.join(join_table, join_type)
-            relation = relation.on(
-              join_table[fk].
-              eq(parent_table[reflection.active_record.primary_key])
-            )
-
-            join_target_table(
-              relation,
-              target_table[reflection.klass.primary_key].
-              eq(join_table[klass_fk])
-            )
-          end
-
-          def join_has_many_to(relation)
-            if reflection.options[:through]
-              join_has_many_through_to(relation)
-            elsif reflection.options[:as]
-              join_has_many_polymorphic_to(relation)
-            else
-              foreign_key = options[:foreign_key] || reflection.active_record.name.foreign_key
-              primary_key = options[:primary_key] || parent.primary_key
-
-              join_target_table(
-                relation,
-                target_table[foreign_key].
-                eq(parent_table[primary_key])
-              )
-            end
-          end
-          alias :join_has_one_to :join_has_many_to
-
-          def join_has_many_through_to(relation)
-            join_table = Arel::Table.new(
-              through_reflection.klass.table_name
-            ).alias @aliased_join_table_name
-
-            jt_conditions = []
-            first_key = second_key = nil
-
-            if through_reflection.macro == :belongs_to
-              jt_primary_key = through_reflection.foreign_key
-              jt_foreign_key = through_reflection.association_primary_key
-            else
-              jt_primary_key = through_reflection.active_record_primary_key
-              jt_foreign_key = through_reflection.foreign_key
-
-              if through_reflection.options[:as] # has_many :through against a polymorphic join
-                jt_conditions <<
-                join_table["#{through_reflection.options[:as]}_type"].
-                  eq(parent.active_record.base_class.name)
-              end
-            end
-
-            case source_reflection.macro
-            when :has_many
-              second_key = options[:foreign_key] || primary_key
-
-              if source_reflection.options[:as]
-                first_key = "#{source_reflection.options[:as]}_id"
-              else
-                first_key = through_reflection.klass.base_class.to_s.foreign_key
-              end
-
-              unless through_reflection.klass.descends_from_active_record?
-                jt_conditions <<
-                join_table[through_reflection.active_record.inheritance_column].
-                  eq(through_reflection.klass.sti_name)
-              end
-            when :belongs_to
-              first_key = primary_key
-
-              if reflection.options[:source_type]
-                second_key = source_reflection.association_foreign_key
-
-                jt_conditions <<
-                join_table[reflection.source_reflection.foreign_type].
-                  eq(reflection.options[:source_type])
-              else
-                second_key = source_reflection.foreign_key
-              end
-            end
-
-            jt_conditions <<
-            parent_table[jt_primary_key].
-              eq(join_table[jt_foreign_key])
-
-            if through_reflection.options[:conditions]
-              jt_conditions << process_conditions(through_reflection.options[:conditions], aliased_table_name)
-            end
-
-            relation = relation.join(join_table, join_type).on(*jt_conditions)
-
-            join_target_table(
-              relation,
-              target_table[first_key].eq(join_table[second_key])
-            )
-          end
-
-          def join_has_many_polymorphic_to(relation)
-            join_target_table(
-              relation,
-              target_table["#{reflection.options[:as]}_id"].
-              eq(parent_table[parent.primary_key]).and(
-              target_table["#{reflection.options[:as]}_type"].
-              eq(parent.active_record.base_class.name))
-            )
-          end
-
-          def join_belongs_to_to(relation)
-            foreign_key = options[:foreign_key] || reflection.foreign_key
-            primary_key = options[:primary_key] || reflection.klass.primary_key
-
-            join_target_table(
-              relation,
-              target_table[primary_key].eq(parent_table[foreign_key])
-            )
-          end
-        end
-      end
-    end
-  end
-end
diff --git a/activerecord/lib/active_record/associations/class_methods/join_dependency/join_base.rb b/activerecord/lib/active_record/associations/class_methods/join_dependency/join_base.rb
deleted file mode 100644
index 67567f06df..0000000000
--- a/activerecord/lib/active_record/associations/class_methods/join_dependency/join_base.rb
+++ /dev/null
@@ -1,26 +0,0 @@
-module ActiveRecord
-  module Associations
-    module ClassMethods
-      class JoinDependency # :nodoc:
-        class JoinBase < JoinPart # :nodoc:
-          def ==(other)
-            other.class == self.class &&
-              other.active_record == active_record
-          end
-
-          def aliased_prefix
-            "t0"
-          end
-
-          def table
-            Arel::Table.new(table_name, arel_engine)
-          end
-
-          def aliased_table_name
-            active_record.table_name
-          end
-        end
-      end
-    end
-  end
-end
diff --git a/activerecord/lib/active_record/associations/class_methods/join_dependency/join_part.rb b/activerecord/lib/active_record/associations/class_methods/join_dependency/join_part.rb
deleted file mode 100644
index cd16ae5a8b..0000000000
--- a/activerecord/lib/active_record/associations/class_methods/join_dependency/join_part.rb
+++ /dev/null
@@ -1,80 +0,0 @@
-module ActiveRecord
-  module Associations
-    module ClassMethods
-      class JoinDependency # :nodoc:
-        # A JoinPart represents a part of a JoinDependency. It is an abstract class, inherited
-        # by JoinBase and JoinAssociation. A JoinBase represents the Active Record which
-        # everything else is being joined onto. A JoinAssociation represents an association which
-        # is joining to the base. A JoinAssociation may result in more than one actual join
-        # operations (for example a has_and_belongs_to_many JoinAssociation would result in
-        # two; one for the join table and one for the target table).
-        class JoinPart # :nodoc:
-          # The Active Record class which this join part is associated 'about'; for a JoinBase
-          # this is the actual base model, for a JoinAssociation this is the target model of the
-          # association.
-          attr_reader :active_record
-
-          delegate :table_name, :column_names, :primary_key, :reflections, :arel_engine, :to => :active_record
-
-          def initialize(active_record)
-            @active_record = active_record
-            @cached_record = {}
-            @column_names_with_alias = nil
-          end
-
-          def aliased_table
-            Arel::Nodes::TableAlias.new aliased_table_name, table
-          end
-
-          def ==(other)
-            raise NotImplementedError
-          end
-
-          # An Arel::Table for the active_record
-          def table
-            raise NotImplementedError
-          end
-
-          # The prefix to be used when aliasing columns in the active_record's table
-          def aliased_prefix
-            raise NotImplementedError
-          end
-
-          # The alias for the active_record's table
-          def aliased_table_name
-            raise NotImplementedError
-          end
-
-          # The alias for the primary key of the active_record's table
-          def aliased_primary_key
-            "#{aliased_prefix}_r0"
-          end
-
-          # An array of [column_name, alias] pairs for the table
-          def column_names_with_alias
-            unless @column_names_with_alias
-              @column_names_with_alias = []
-
-              ([primary_key] + (column_names - [primary_key])).each_with_index do |column_name, i|
-                @column_names_with_alias << [column_name, "#{aliased_prefix}_r#{i}"]
-              end
-            end
-            @column_names_with_alias
-          end
-
-          def extract_record(row)
-            Hash[column_names_with_alias.map{|cn, an| [cn, row[an]]}]
-          end
-
-          def record_id(row)
-            row[aliased_primary_key]
-          end
-
-          def instantiate(row)
-            @cached_record[record_id(row)] ||= active_record.send(:instantiate, extract_record(row))
-          end
-        end
-      end
-    end
-  end
-end
diff --git a/activerecord/lib/active_record/associations/join_dependency.rb b/activerecord/lib/active_record/associations/join_dependency.rb
new file mode 100644
index 0000000000..c7c3cf521c
--- /dev/null
+++ b/activerecord/lib/active_record/associations/join_dependency.rb
@@ -0,0 +1,231 @@
+module ActiveRecord
+  module Associations
+    class JoinDependency # :nodoc:
+      autoload :JoinPart,        'active_record/associations/join_dependency/join_part'
+      autoload :JoinBase,        'active_record/associations/join_dependency/join_base'
+      autoload :JoinAssociation, 'active_record/associations/join_dependency/join_association'
+
+      attr_reader :join_parts, :reflections, :table_aliases, :active_record
+
+      def initialize(base, associations, joins)
+        @active_record         = base
+        @table_joins           = joins
+        @join_parts            = [JoinBase.new(base)]
+        @associations          = {}
+        @reflections           = []
+        @table_aliases         = Hash.new do |h,name|
+          h[name] = count_aliases_from_table_joins(name.downcase)
+        end
+        @table_aliases[base.table_name] = 1
+        build(associations)
+      end
+
+      def graft(*associations)
+        associations.each do |association|
+          join_associations.detect {|a| association == a} ||
+            build(association.reflection.name, association.find_parent_in(self) || join_base, association.join_type)
+        end
+        self
+      end
+
+      def join_associations
+        join_parts.last(join_parts.length - 1)
+      end
+
+      def join_base
+        join_parts.first
+      end
+
+      def columns
+        join_parts.collect { |join_part|
+          table = join_part.aliased_table
+          join_part.column_names_with_alias.collect{ |column_name, aliased_name|
+            table[column_name].as Arel.sql(aliased_name)
+          }
+        }.flatten
+      end
+
+      def count_aliases_from_table_joins(name)
+        return 0 if Arel::Table === @table_joins
+
+        # quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase
+        quoted_name = active_record.connection.quote_table_name(name).downcase
+
+        @table_joins.map { |join|
+          # Table names + table aliases
+          join.left.downcase.scan(
+            /join(?:\s+\w+)?\s+(\S+\s+)?#{quoted_name}\son/
+          ).size
+        }.sum
+      end
+
+      def instantiate(rows)
+        primary_key = join_base.aliased_primary_key
+        parents = {}
+
+        records = rows.map { |model|
+          primary_id = model[primary_key]
+          parent = parents[primary_id] ||= join_base.instantiate(model)
+          construct(parent, @associations, join_associations, model)
+          parent
+        }.uniq
+
+        remove_duplicate_results!(active_record, records, @associations)
+        records
+      end
+
+      def remove_duplicate_results!(base, records, associations)
+        case associations
+        when Symbol, String
+          reflection = base.reflections[associations]
+          remove_uniq_by_reflection(reflection, records)
+        when Array
+          associations.each do |association|
+            remove_duplicate_results!(base, records, association)
+          end
+        when Hash
+          associations.keys.each do |name|
+            reflection = base.reflections[name]
+            remove_uniq_by_reflection(reflection, records)
+
+            parent_records = []
+            records.each do |record|
+              if descendant = record.send(reflection.name)
+                if reflection.collection?
+                  parent_records.concat descendant.target.uniq
+                else
+                  parent_records << descendant
+                end
+              end
+            end
+
+            remove_duplicate_results!(reflection.klass, parent_records, associations[name]) unless parent_records.empty?
+          end
+        end
+      end
+
+      protected
+
+      def cache_joined_association(association)
+        associations = []
+        parent = association.parent
+        while parent != join_base
+          associations.unshift(parent.reflection.name)
+          parent = parent.parent
+        end
+        ref = @associations
+        associations.each do |key|
+          ref = ref[key]
+        end
+        ref[association.reflection.name] ||= {}
+      end
+
+      def build(associations, parent = nil, join_type = Arel::InnerJoin)
+        parent ||= join_parts.last
+        case associations
+        when Symbol, String
+          reflection = parent.reflections[associations.to_s.intern] or
+          raise ConfigurationError, "Association named '#{ associations }' was not found; perhaps you misspelled it?"
+          unless join_association = find_join_association(reflection, parent)
+            @reflections << reflection
+            join_association = build_join_association(reflection, parent)
+            join_association.join_type = join_type
+            @join_parts << join_association
+            cache_joined_association(join_association)
+          end
+          join_association
+        when Array
+          associations.each do |association|
+            build(association, parent, join_type)
+          end
+        when Hash
+          associations.keys.sort_by { |a| a.to_s }.each do |name|
+            join_association = build(name, parent, join_type)
+            build(associations[name], join_association, join_type)
+          end
+        else
+          raise ConfigurationError, associations.inspect
+        end
+      end
+
+      def find_join_association(name_or_reflection, parent)
+        if String === name_or_reflection
+          name_or_reflection = name_or_reflection.to_sym
+        end
+
+        join_associations.detect { |j|
+          j.reflection == name_or_reflection && j.parent == parent
+        }
+      end
+
+      def remove_uniq_by_reflection(reflection, records)
+        if reflection && reflection.collection?
+          records.each { |record| record.send(reflection.name).target.uniq! }
+        end
+      end
+
+      def build_join_association(reflection, parent)
+        JoinAssociation.new(reflection, self, parent)
+      end
+
+      def construct(parent, associations, join_parts, row)
+        case associations
+        when Symbol, String
+          name = associations.to_s
+
+          join_part = join_parts.detect { |j|
+            j.reflection.name.to_s == name &&
+              j.parent_table_name == parent.class.table_name }
+
+            raise(ConfigurationError, "No such association") unless join_part
+
+            join_parts.delete(join_part)
+            construct_association(parent, join_part, row)
+        when Array
+          associations.each do |association|
+            construct(parent, association, join_parts, row)
+          end
+        when Hash
+          associations.sort_by { |k,_| k.to_s }.each do |association_name, assoc|
+            association = construct(parent, association_name, join_parts, row)
+            construct(association, assoc, join_parts, row) if association
+          end
+        else
+          raise ConfigurationError, associations.inspect
+        end
+      end
+
+      def construct_association(record, join_part, row)
+        return if record.id.to_s != join_part.parent.record_id(row).to_s
+
+        macro = join_part.reflection.macro
+        if macro == :has_one
+          return if record.association_cache.key?(join_part.reflection.name)
+          association = join_part.instantiate(row) unless row[join_part.aliased_primary_key].nil?
+          set_target_and_inverse(join_part, association, record)
+        else
+          return if row[join_part.aliased_primary_key].nil?
+          association = join_part.instantiate(row)
+          case macro
+          when :has_many, :has_and_belongs_to_many
+            other = record.association(join_part.reflection.name)
+            other.loaded!
+            other.target.push(association)
+            other.set_inverse_instance(association)
+          when :belongs_to
+            set_target_and_inverse(join_part, association, record)
+          else
+            raise ConfigurationError, "unknown macro: #{join_part.reflection.macro}"
+          end
+        end
+        association
+      end
+
+      def set_target_and_inverse(join_part, association, record)
+        other = record.association(join_part.reflection.name)
+        other.target = association
+        other.set_inverse_instance(association)
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/join_dependency/join_association.rb b/activerecord/lib/active_record/associations/join_dependency/join_association.rb
new file mode 100644
index 0000000000..ebe39c35fe
--- /dev/null
+++ b/activerecord/lib/active_record/associations/join_dependency/join_association.rb
@@ -0,0 +1,279 @@
+module ActiveRecord
+  module Associations
+    class JoinDependency # :nodoc:
+      class JoinAssociation < JoinPart # :nodoc:
+        # The reflection of the association represented
+        attr_reader :reflection
+
+        # The JoinDependency object which this JoinAssociation exists within. This is mainly
+        # relevant for generating aliases which do not conflict with other joins which are
+        # part of the query.
+        attr_reader :join_dependency
+
+        # A JoinBase instance representing the active record we are joining onto.
+        # (So in Author.has_many :posts, the Author would be that base record.)
+        attr_reader :parent
+
+        # What type of join will be generated, either Arel::InnerJoin (default) or Arel::OuterJoin
+        attr_accessor :join_type
+
+        # These implement abstract methods from the superclass
+        attr_reader :aliased_prefix, :aliased_table_name
+
+        delegate :options, :through_reflection, :source_reflection, :to => :reflection
+        delegate :table, :table_name, :to => :parent, :prefix => :parent
+
+        def initialize(reflection, join_dependency, parent = nil)
+          reflection.check_validity!
+
+          if reflection.options[:polymorphic]
+            raise EagerLoadPolymorphicError.new(reflection)
+          end
+
+          super(reflection.klass)
+
+          @reflection      = reflection
+          @join_dependency = join_dependency
+          @parent          = parent
+          @join_type       = Arel::InnerJoin
+          @aliased_prefix  = "t#{ join_dependency.join_parts.size }"
+
+          # This must be done eagerly upon initialisation because the alias which is produced
+          # depends on the state of the join dependency, but we want it to work the same way
+          # every time.
+          allocate_aliases
+          @table = Arel::Table.new(
+            table_name, :as => aliased_table_name, :engine => arel_engine
+          )
+        end
+
+        def ==(other)
+          other.class == self.class &&
+            other.reflection == reflection &&
+            other.parent == parent
+        end
+
+        def find_parent_in(other_join_dependency)
+          other_join_dependency.join_parts.detect do |join_part|
+            parent == join_part
+          end
+        end
+
+        def join_to(relation)
+          send("join_#{reflection.macro}_to", relation)
+        end
+
+        def join_relation(joining_relation)
+          self.join_type = Arel::OuterJoin
+          joining_relation.joins(self)
+        end
+
+        attr_reader :table
+        # More semantic name given we are talking about associations
+        alias_method :target_table, :table
+
+        protected
+
+        def aliased_table_name_for(name, suffix = nil)
+          aliases = @join_dependency.table_aliases
+
+          if aliases[name] != 0 # We need an alias
+            connection = active_record.connection
+
+            name = connection.table_alias_for "#{pluralize(reflection.name)}_#{parent_table_name}#{suffix}"
+            aliases[name] += 1
+            name = name[0, connection.table_alias_length-3] + "_#{aliases[name]}" if aliases[name] > 1
+          else
+            aliases[name] += 1
+          end
+
+          name
+        end
+
+        def pluralize(table_name)
+          ActiveRecord::Base.pluralize_table_names ? table_name.to_s.pluralize : table_name
+        end
+
+        private
+
+        def allocate_aliases
+          @aliased_table_name = aliased_table_name_for(table_name)
+
+          if reflection.macro == :has_and_belongs_to_many
+            @aliased_join_table_name = aliased_table_name_for(reflection.options[:join_table], "_join")
+          elsif [:has_many, :has_one].include?(reflection.macro) && reflection.options[:through]
+            @aliased_join_table_name = aliased_table_name_for(reflection.through_reflection.klass.table_name, "_join")
+          end
+        end
+
+        def process_conditions(conditions, table_name)
+          if conditions.respond_to?(:to_proc)
+            conditions = instance_eval(&conditions)
+          end
+
+          Arel.sql(sanitize_sql(conditions, table_name))
+        end
+
+        def sanitize_sql(condition, table_name)
+          active_record.send(:sanitize_sql, condition, table_name)
+        end
+
+        def join_target_table(relation, condition)
+          conditions = [condition]
+
+          # If the target table is an STI model then we must be sure to only include records of
+          # its type and its sub-types.
+          unless active_record.descends_from_active_record?
+            sti_column    = target_table[active_record.inheritance_column]
+            subclasses    = active_record.descendants
+            sti_condition = sti_column.eq(active_record.sti_name)
+
+            conditions << subclasses.inject(sti_condition) { |attr,subclass|
+              attr.or(sti_column.eq(subclass.sti_name))
+            }
+          end
+
+          # If the reflection has conditions, add them
+          if options[:conditions]
+            conditions << process_conditions(options[:conditions], aliased_table_name)
+          end
+
+          ands = relation.create_and(conditions)
+
+          join = relation.create_join(
+            target_table,
+            relation.create_on(ands),
+            join_type)
+
+          relation.from join
+        end
+
+        def join_has_and_belongs_to_many_to(relation)
+          join_table = Arel::Table.new(
+            options[:join_table]
+          ).alias(@aliased_join_table_name)
+
+          fk       = options[:foreign_key]             || reflection.active_record.to_s.foreign_key
+          klass_fk = options[:association_foreign_key] || reflection.klass.to_s.foreign_key
+
+          relation = relation.join(join_table, join_type)
+          relation = relation.on(
+            join_table[fk].
+            eq(parent_table[reflection.active_record.primary_key])
+          )
+
+          join_target_table(
+            relation,
+            target_table[reflection.klass.primary_key].
+            eq(join_table[klass_fk])
+          )
+        end
+
+        def join_has_many_to(relation)
+          if reflection.options[:through]
+            join_has_many_through_to(relation)
+          elsif reflection.options[:as]
+            join_has_many_polymorphic_to(relation)
+          else
+            foreign_key = options[:foreign_key] || reflection.active_record.name.foreign_key
+            primary_key = options[:primary_key] || parent.primary_key
+
+            join_target_table(
+              relation,
+              target_table[foreign_key].
+              eq(parent_table[primary_key])
+            )
+          end
+        end
+        alias :join_has_one_to :join_has_many_to
+
+        def join_has_many_through_to(relation)
+          join_table = Arel::Table.new(
+            through_reflection.klass.table_name
+          ).alias @aliased_join_table_name
+
+          jt_conditions = []
+          first_key = second_key = nil
+
+          if through_reflection.macro == :belongs_to
+            jt_primary_key = through_reflection.foreign_key
+            jt_foreign_key = through_reflection.association_primary_key
+          else
+            jt_primary_key = through_reflection.active_record_primary_key
+            jt_foreign_key = through_reflection.foreign_key
+
+            if through_reflection.options[:as] # has_many :through against a polymorphic join
+              jt_conditions <<
+              join_table["#{through_reflection.options[:as]}_type"].
+                eq(parent.active_record.base_class.name)
+            end
+          end
+
+          case source_reflection.macro
+          when :has_many
+            second_key = options[:foreign_key] || primary_key
+
+            if source_reflection.options[:as]
+              first_key = "#{source_reflection.options[:as]}_id"
+            else
+              first_key = through_reflection.klass.base_class.to_s.foreign_key
+            end
+
+            unless through_reflection.klass.descends_from_active_record?
+              jt_conditions <<
+              join_table[through_reflection.active_record.inheritance_column].
+                eq(through_reflection.klass.sti_name)
+            end
+          when :belongs_to
+            first_key = primary_key
+
+            if reflection.options[:source_type]
+              second_key = source_reflection.association_foreign_key
+
+              jt_conditions <<
+              join_table[reflection.source_reflection.foreign_type].
+                eq(reflection.options[:source_type])
+            else
+              second_key = source_reflection.foreign_key
+            end
+          end
+
+          jt_conditions <<
+          parent_table[jt_primary_key].
+            eq(join_table[jt_foreign_key])
+
+          if through_reflection.options[:conditions]
+            jt_conditions << process_conditions(through_reflection.options[:conditions], aliased_table_name)
+          end
+
+          relation = relation.join(join_table, join_type).on(*jt_conditions)
+
+          join_target_table(
+            relation,
+            target_table[first_key].eq(join_table[second_key])
+          )
+        end
+
+        def join_has_many_polymorphic_to(relation)
+          join_target_table(
+            relation,
+            target_table["#{reflection.options[:as]}_id"].
+            eq(parent_table[parent.primary_key]).and(
+            target_table["#{reflection.options[:as]}_type"].
+            eq(parent.active_record.base_class.name))
+          )
+        end
+
+        def join_belongs_to_to(relation)
+          foreign_key = options[:foreign_key] || reflection.foreign_key
+          primary_key = options[:primary_key] || reflection.klass.primary_key
+
+          join_target_table(
+            relation,
+            target_table[primary_key].eq(parent_table[foreign_key])
+          )
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/join_dependency/join_base.rb b/activerecord/lib/active_record/associations/join_dependency/join_base.rb
new file mode 100644
index 0000000000..3920e84976
--- /dev/null
+++ b/activerecord/lib/active_record/associations/join_dependency/join_base.rb
@@ -0,0 +1,24 @@
+module ActiveRecord
+  module Associations
+    class JoinDependency # :nodoc:
+      class JoinBase < JoinPart # :nodoc:
+        def ==(other)
+          other.class == self.class &&
+            other.active_record == active_record
+        end
+
+        def aliased_prefix
+          "t0"
+        end
+
+        def table
+          Arel::Table.new(table_name, arel_engine)
+        end
+
+        def aliased_table_name
+          active_record.table_name
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/join_dependency/join_part.rb b/activerecord/lib/active_record/associations/join_dependency/join_part.rb
new file mode 100644
index 0000000000..3279e56e7d
--- /dev/null
+++ b/activerecord/lib/active_record/associations/join_dependency/join_part.rb
@@ -0,0 +1,78 @@
+module ActiveRecord
+  module Associations
+    class JoinDependency # :nodoc:
+      # A JoinPart represents a part of a JoinDependency. It is an abstract class, inherited
+      # by JoinBase and JoinAssociation. A JoinBase represents the Active Record which
+      # everything else is being joined onto. A JoinAssociation represents an association which
+      # is joining to the base. A JoinAssociation may result in more than one actual join
+      # operations (for example a has_and_belongs_to_many JoinAssociation would result in
+      # two; one for the join table and one for the target table).
+      class JoinPart # :nodoc:
+        # The Active Record class which this join part is associated 'about'; for a JoinBase
+        # this is the actual base model, for a JoinAssociation this is the target model of the
+        # association.
+        attr_reader :active_record
+
+        delegate :table_name, :column_names, :primary_key, :reflections, :arel_engine, :to => :active_record
+
+        def initialize(active_record)
+          @active_record = active_record
+          @cached_record = {}
+          @column_names_with_alias = nil
+        end
+
+        def aliased_table
+          Arel::Nodes::TableAlias.new aliased_table_name, table
+        end
+
+        def ==(other)
+          raise NotImplementedError
+        end
+
+        # An Arel::Table for the active_record
+        def table
+          raise NotImplementedError
+        end
+
+        # The prefix to be used when aliasing columns in the active_record's table
+        def aliased_prefix
+          raise NotImplementedError
+        end
+
+        # The alias for the active_record's table
+        def aliased_table_name
+          raise NotImplementedError
+        end
+
+        # The alias for the primary key of the active_record's table
+        def aliased_primary_key
+          "#{aliased_prefix}_r0"
+        end
+
+        # An array of [column_name, alias] pairs for the table
+        def column_names_with_alias
+          unless @column_names_with_alias
+            @column_names_with_alias = []
+
+            ([primary_key] + (column_names - [primary_key])).each_with_index do |column_name, i|
+              @column_names_with_alias << [column_name, "#{aliased_prefix}_r#{i}"]
+            end
+          end
+          @column_names_with_alias
+        end
+
+        def extract_record(row)
+          Hash[column_names_with_alias.map{|cn, an| [cn, row[an]]}]
+        end
+
+        def record_id(row)
+          row[aliased_primary_key]
+        end
+
+        def instantiate(row)
+          @cached_record[record_id(row)] ||= active_record.send(:instantiate, extract_record(row))
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/preloader.rb b/activerecord/lib/active_record/associations/preloader.rb
new file mode 100644
index 0000000000..fafed94ff2
--- /dev/null
+++ b/activerecord/lib/active_record/associations/preloader.rb
@@ -0,0 +1,177 @@
+module ActiveRecord
+  module Associations
+    # Implements the details of eager loading of Active Record associations.
+    #
+    # Note that 'eager loading' and 'preloading' are actually the same thing.
+    # However, there are two different eager loading strategies.
+    #
+    # The first one is by using table joins. This was only strategy available
+    # prior to Rails 2.1. Suppose that you have an Author model with columns
+    # 'name' and 'age', and a Book model with columns 'name' and 'sales'. Using
+    # this strategy, Active Record would try to retrieve all data for an author
+    # and all of its books via a single query:
+    #
+    #   SELECT * FROM authors
+    #   LEFT OUTER JOIN books ON authors.id = books.id
+    #   WHERE authors.name = 'Ken Akamatsu'
+    #
+    # However, this could result in many rows that contain redundant data. After
+    # having received the first row, we already have enough data to instantiate
+    # the Author object. In all subsequent rows, only the data for the joined
+    # 'books' table is useful; the joined 'authors' data is just redundant, and
+    # processing this redundant data takes memory and CPU time. The problem
+    # quickly becomes worse and worse as the level of eager loading increases
+    # (i.e. if Active Record is to eager load the associations' associations as
+    # well).
+    #
+    # The second strategy is to use multiple database queries, one for each
+    # level of association. Since Rails 2.1, this is the default strategy. In
+    # situations where a table join is necessary (e.g. when the +:conditions+
+    # option references an association's column), it will fallback to the table
+    # join strategy.
+    class Preloader #:nodoc:
+      autoload :Association,           'active_record/associations/preloader/association'
+      autoload :SingularAssociation,   'active_record/associations/preloader/singular_association'
+      autoload :CollectionAssociation, 'active_record/associations/preloader/collection_association'
+      autoload :ThroughAssociation,    'active_record/associations/preloader/through_association'
+
+      autoload :HasMany,             'active_record/associations/preloader/has_many'
+      autoload :HasManyThrough,      'active_record/associations/preloader/has_many_through'
+      autoload :HasOne,              'active_record/associations/preloader/has_one'
+      autoload :HasOneThrough,       'active_record/associations/preloader/has_one_through'
+      autoload :HasAndBelongsToMany, 'active_record/associations/preloader/has_and_belongs_to_many'
+      autoload :BelongsTo,           'active_record/associations/preloader/belongs_to'
+
+      attr_reader :records, :associations, :options, :model
+
+      # Eager loads the named associations for the given Active Record record(s).
+      #
+      # In this description, 'association name' shall refer to the name passed
+      # to an association creation method. For example, a model that specifies
+      # <tt>belongs_to :author</tt>, <tt>has_many :buyers</tt> has association
+      # names +:author+ and +:buyers+.
+      #
+      # == Parameters
+      # +records+ is an array of ActiveRecord::Base. This array needs not be flat,
+      # i.e. +records+ itself may also contain arrays of records. In any case,
+      # +preload_associations+ will preload the all associations records by
+      # flattening +records+.
+      #
+      # +associations+ specifies one or more associations that you want to
+      # preload. It may be:
+      # - a Symbol or a String which specifies a single association name. For
+      #   example, specifying +:books+ allows this method to preload all books
+      #   for an Author.
+      # - an Array which specifies multiple association names. This array
+      #   is processed recursively. For example, specifying <tt>[:avatar, :books]</tt>
+      #   allows this method to preload an author's avatar as well as all of his
+      #   books.
+      # - a Hash which specifies multiple association names, as well as
+      #   association names for the to-be-preloaded association objects. For
+      #   example, specifying <tt>{ :author => :avatar }</tt> will preload a
+      #   book's author, as well as that author's avatar.
+      #
+      # +:associations+ has the same format as the +:include+ option for
+      # <tt>ActiveRecord::Base.find</tt>. So +associations+ could look like this:
+      #
+      #   :books
+      #   [ :books, :author ]
+      #   { :author => :avatar }
+      #   [ :books, { :author => :avatar } ]
+      #
+      # +options+ contains options that will be passed to ActiveRecord::Base#find
+      # (which is called under the hood for preloading records). But it is passed
+      # only one level deep in the +associations+ argument, i.e. it's not passed
+      # to the child associations when +associations+ is a Hash.
+      def initialize(records, associations, options = {})
+        @records      = Array.wrap(records).compact.uniq
+        @associations = Array.wrap(associations)
+        @options      = options
+      end
+
+      def run
+        unless records.empty?
+          associations.each { |association| preload(association) }
+        end
+      end
+
+      private
+
+      def preload(association)
+        case association
+        when Hash
+          preload_hash(association)
+        when String, Symbol
+          preload_one(association.to_sym)
+        else
+          raise ArgumentError, "#{association.inspect} was not recognised for preload"
+        end
+      end
+
+      def preload_hash(association)
+        association.each do |parent, child|
+          Preloader.new(records, parent, options).run
+          Preloader.new(records.map { |record| record.send(parent) }.flatten, child).run
+        end
+      end
+
+      # Not all records have the same class, so group then preload group on the reflection
+      # itself so that if various subclass share the same association then we do not split
+      # them unnecessarily
+      #
+      # Additionally, polymorphic belongs_to associations can have multiple associated
+      # classes, depending on the polymorphic_type field. So we group by the classes as
+      # well.
+      def preload_one(association)
+        grouped_records(association).each do |reflection, klasses|
+          klasses.each do |klass, records|
+            preloader_for(reflection).new(klass, records, reflection, options).run
+          end
+        end
+      end
+
+      def grouped_records(association)
+        Hash[
+          records_by_reflection(association).map do |reflection, records|
+            [reflection, records.group_by { |record| association_klass(reflection, record) }]
+          end
+        ]
+      end
+
+      def records_by_reflection(association)
+        records.group_by do |record|
+          reflection = record.class.reflections[association]
+
+          unless reflection
+            raise ActiveRecord::ConfigurationError, "Association named '#{association}' was not found; " \
+                                                    "perhaps you misspelled it?"
+          end
+
+          reflection
+        end
+      end
+
+      def association_klass(reflection, record)
+        if reflection.macro == :belongs_to && reflection.options[:polymorphic]
+          klass = record.send(reflection.foreign_type)
+          klass && klass.constantize
+        else
+          reflection.klass
+        end
+      end
+
+      def preloader_for(reflection)
+        case reflection.macro
+        when :has_many
+          reflection.options[:through] ? HasManyThrough : HasMany
+        when :has_one
+          reflection.options[:through] ? HasOneThrough : HasOne
+        when :has_and_belongs_to_many
+          HasAndBelongsToMany
+        when :belongs_to
+          BelongsTo
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/preloader/association.rb b/activerecord/lib/active_record/associations/preloader/association.rb
new file mode 100644
index 0000000000..7256dd5288
--- /dev/null
+++ b/activerecord/lib/active_record/associations/preloader/association.rb
@@ -0,0 +1,126 @@
+module ActiveRecord
+  module Associations
+    class Preloader
+      class Association #:nodoc:
+        attr_reader :owners, :reflection, :preload_options, :model, :klass
+
+        def initialize(klass, owners, reflection, preload_options)
+          @klass           = klass
+          @owners          = owners
+          @reflection      = reflection
+          @preload_options = preload_options || {}
+          @model           = owners.first && owners.first.class
+          @scoped          = nil
+          @owners_by_key   = nil
+        end
+
+        def run
+          unless owners.first.association(reflection.name).loaded?
+            preload
+          end
+        end
+
+        def preload
+          raise NotImplementedError
+        end
+
+        def scoped
+          @scoped ||= build_scope
+        end
+
+        def records_for(ids)
+          scoped.where(association_key.in(ids))
+        end
+
+        def table
+          klass.arel_table
+        end
+
+        # The name of the key on the associated records
+        def association_key_name
+          raise NotImplementedError
+        end
+
+        # This is overridden by HABTM as the condition should be on the foreign_key column in
+        # the join table
+        def association_key
+          table[association_key_name]
+        end
+
+        # The name of the key on the model which declares the association
+        def owner_key_name
+          raise NotImplementedError
+        end
+
+        # We're converting to a string here because postgres will return the aliased association
+        # key in a habtm as a string (for whatever reason)
+        def owners_by_key
+          @owners_by_key ||= owners.group_by do |owner|
+            key = owner[owner_key_name]
+            key && key.to_s
+          end
+        end
+
+        def options
+          reflection.options
+        end
+
+        private
+
+        def associated_records_by_owner
+          owner_keys = owners.map { |owner| owner[owner_key_name] }.compact.uniq
+
+          if klass.nil? || owner_keys.empty?
+            records = []
+          else
+            # Some databases impose a limit on the number of ids in a list (in Oracle it's 1000)
+            # Make several smaller queries if necessary or make one query if the adapter supports it
+            sliced  = owner_keys.each_slice(model.connection.in_clause_length || owner_keys.size)
+            records = sliced.map { |slice| records_for(slice) }.flatten
+          end
+
+          # Each record may have multiple owners, and vice-versa
+          records_by_owner = Hash[owners.map { |owner| [owner, []] }]
+          records.each do |record|
+            owner_key = record[association_key_name].to_s
+
+            owners_by_key[owner_key].each do |owner|
+              records_by_owner[owner] << record
+            end
+          end
+          records_by_owner
+        end
+
+        def build_scope
+          scope = klass.scoped
+
+          scope = scope.where(process_conditions(options[:conditions]))
+          scope = scope.where(process_conditions(preload_options[:conditions]))
+
+          scope = scope.select(preload_options[:select] || options[:select] || table[Arel.star])
+          scope = scope.includes(preload_options[:include] || options[:include])
+
+          if options[:as]
+            scope = scope.where(
+              klass.table_name => {
+                reflection.type => model.base_class.sti_name
+              }
+            )
+          end
+
+          scope
+        end
+
+        def process_conditions(conditions)
+          if conditions.respond_to?(:to_proc)
+            conditions = klass.send(:instance_eval, &conditions)
+          end
+
+          if conditions
+            klass.send(:sanitize_sql, conditions)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/preloader/belongs_to.rb b/activerecord/lib/active_record/associations/preloader/belongs_to.rb
new file mode 100644
index 0000000000..5091d4717a
--- /dev/null
+++ b/activerecord/lib/active_record/associations/preloader/belongs_to.rb
@@ -0,0 +1,17 @@
+module ActiveRecord
+  module Associations
+    class Preloader
+      class BelongsTo < SingularAssociation #:nodoc:
+
+        def association_key_name
+          reflection.options[:primary_key] || klass && klass.primary_key
+        end
+
+        def owner_key_name
+          reflection.foreign_key
+        end
+
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/preloader/collection_association.rb b/activerecord/lib/active_record/associations/preloader/collection_association.rb
new file mode 100644
index 0000000000..c248aeaaf6
--- /dev/null
+++ b/activerecord/lib/active_record/associations/preloader/collection_association.rb
@@ -0,0 +1,24 @@
+module ActiveRecord
+  module Associations
+    class Preloader
+      class CollectionAssociation < Association #:nodoc:
+
+        private
+
+        def build_scope
+          super.order(preload_options[:order] || options[:order])
+        end
+
+        def preload
+          associated_records_by_owner.each do |owner, records|
+            association = owner.association(reflection.name)
+            association.loaded!
+            association.target.concat(records)
+            records.each { |record| association.set_inverse_instance(record) }
+          end
+        end
+
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/preloader/has_and_belongs_to_many.rb b/activerecord/lib/active_record/associations/preloader/has_and_belongs_to_many.rb
new file mode 100644
index 0000000000..24be279449
--- /dev/null
+++ b/activerecord/lib/active_record/associations/preloader/has_and_belongs_to_many.rb
@@ -0,0 +1,60 @@
+module ActiveRecord
+  module Associations
+    class Preloader
+      class HasAndBelongsToMany < CollectionAssociation #:nodoc:
+        attr_reader :join_table
+
+        def initialize(klass, records, reflection, preload_options)
+          super
+          @join_table = Arel::Table.new(options[:join_table]).alias('t0')
+        end
+
+        # Unlike the other associations, we want to get a raw array of rows so that we can
+        # access the aliased column on the join table
+        def records_for(ids)
+          scope = super
+          klass.connection.select_all(scope.arel.to_sql, 'SQL', scope.bind_values)
+        end
+
+        def owner_key_name
+          reflection.active_record_primary_key
+        end
+
+        def association_key_name
+          'ar_association_key_name'
+        end
+
+        def association_key
+          join_table[reflection.foreign_key]
+        end
+
+        private
+
+        # Once we have used the join table column (in super), we manually instantiate the
+        # actual records, ensuring that we don't create more than one instances of the same
+        # record
+        def associated_records_by_owner
+          records = {}
+          super.each do |owner_key, rows|
+            rows.map! { |row| records[row[klass.primary_key]] ||= klass.instantiate(row) }
+          end
+        end
+
+        def build_scope
+          super.joins(join).select(join_select)
+        end
+
+        def join_select
+          association_key.as(Arel.sql(association_key_name))
+        end
+
+        def join
+          condition = table[reflection.association_primary_key].eq(
+            join_table[reflection.association_foreign_key])
+
+          table.create_join(join_table, table.create_on(condition))
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/preloader/has_many.rb b/activerecord/lib/active_record/associations/preloader/has_many.rb
new file mode 100644
index 0000000000..3ea91a8c11
--- /dev/null
+++ b/activerecord/lib/active_record/associations/preloader/has_many.rb
@@ -0,0 +1,17 @@
+module ActiveRecord
+  module Associations
+    class Preloader
+      class HasMany < CollectionAssociation #:nodoc:
+
+        def association_key_name
+          reflection.foreign_key
+        end
+
+        def owner_key_name
+          reflection.active_record_primary_key
+        end
+
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/preloader/has_many_through.rb b/activerecord/lib/active_record/associations/preloader/has_many_through.rb
new file mode 100644
index 0000000000..c6e9ede356
--- /dev/null
+++ b/activerecord/lib/active_record/associations/preloader/has_many_through.rb
@@ -0,0 +1,15 @@
+module ActiveRecord
+  module Associations
+    class Preloader
+      class HasManyThrough < CollectionAssociation #:nodoc:
+        include ThroughAssociation
+
+        def associated_records_by_owner
+          super.each do |owner, records|
+            records.uniq! if options[:uniq]
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/preloader/has_one.rb b/activerecord/lib/active_record/associations/preloader/has_one.rb
new file mode 100644
index 0000000000..848448bb48
--- /dev/null
+++ b/activerecord/lib/active_record/associations/preloader/has_one.rb
@@ -0,0 +1,23 @@
+module ActiveRecord
+  module Associations
+    class Preloader
+      class HasOne < SingularAssociation #:nodoc:
+
+        def association_key_name
+          reflection.foreign_key
+        end
+
+        def owner_key_name
+          reflection.active_record_primary_key
+        end
+
+        private
+
+        def build_scope
+          super.order(preload_options[:order] || options[:order])
+        end
+
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/preloader/has_one_through.rb b/activerecord/lib/active_record/associations/preloader/has_one_through.rb
new file mode 100644
index 0000000000..f063f85574
--- /dev/null
+++ b/activerecord/lib/active_record/associations/preloader/has_one_through.rb
@@ -0,0 +1,9 @@
+module ActiveRecord
+  module Associations
+    class Preloader
+      class HasOneThrough < SingularAssociation #:nodoc:
+        include ThroughAssociation
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/preloader/singular_association.rb b/activerecord/lib/active_record/associations/preloader/singular_association.rb
new file mode 100644
index 0000000000..44e804d785
--- /dev/null
+++ b/activerecord/lib/active_record/associations/preloader/singular_association.rb
@@ -0,0 +1,21 @@
+module ActiveRecord
+  module Associations
+    class Preloader
+      class SingularAssociation < Association #:nodoc:
+
+        private
+
+        def preload
+          associated_records_by_owner.each do |owner, associated_records|
+            record = associated_records.first
+
+            association = owner.association(reflection.name)
+            association.target = record
+            association.set_inverse_instance(record)
+          end
+        end
+
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/preloader/through_association.rb b/activerecord/lib/active_record/associations/preloader/through_association.rb
new file mode 100644
index 0000000000..d630fc4c63
--- /dev/null
+++ b/activerecord/lib/active_record/associations/preloader/through_association.rb
@@ -0,0 +1,66 @@
+module ActiveRecord
+  module Associations
+    class Preloader
+      module ThroughAssociation #:nodoc:
+
+        def through_reflection
+          reflection.through_reflection
+        end
+
+        def source_reflection
+          reflection.source_reflection
+        end
+
+        def associated_records_by_owner
+          through_records = through_records_by_owner
+
+          ActiveRecord::Associations::Preloader.new(
+            through_records.values.flatten,
+            source_reflection.name, options
+          ).run
+
+          through_records.each do |owner, owner_through_records|
+            owner_through_records.map! { |r| r.send(source_reflection.name) }.flatten!
+          end
+        end
+
+        private
+
+        def through_records_by_owner
+          ActiveRecord::Associations::Preloader.new(
+            owners, through_reflection.name,
+            through_options
+          ).run
+
+          Hash[owners.map do |owner|
+            through_records = Array.wrap(owner.send(through_reflection.name))
+
+            # Dont cache the association - we would only be caching a subset
+            if reflection.options[:source_type] && through_reflection.collection?
+              owner.association(through_reflection.name).reset
+            end
+
+            [owner, through_records]
+          end]
+        end
+
+        def through_options
+          through_options = {}
+
+          if options[:source_type]
+            through_options[:conditions] = { reflection.foreign_type => options[:source_type] }
+          else
+            if options[:conditions]
+              through_options[:include]    = options[:include] || options[:source]
+              through_options[:conditions] = options[:conditions]
+            end
+
+            through_options[:order] = options[:order]
+          end
+
+          through_options
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/attribute_methods.rb b/activerecord/lib/active_record/attribute_methods.rb
index 284ae2bebc..5833c65893 100644
--- a/activerecord/lib/active_record/attribute_methods.rb
+++ b/activerecord/lib/active_record/attribute_methods.rb
@@ -10,7 +10,18 @@ module ActiveRecord
       # Generates all the attribute related methods for columns in the database
       # accessors, mutators and query methods.
       def define_attribute_methods
+        return if attribute_methods_generated?
         super(column_names)
+        @attribute_methods_generated = true
+      end
+
+      def attribute_methods_generated?
+        @attribute_methods_generated ||= false
+      end
+
+      def undefine_attribute_methods(*args)
+        super
+        @attribute_methods_generated = false
       end
 
       # Checks whether the method is defined in the model or any of its subclasses
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index e530d2ff87..4db08c774b 100644
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1950,7 +1950,7 @@ MSG
     include AttributeMethods::Dirty
     include ActiveModel::MassAssignmentSecurity
     include Callbacks, ActiveModel::Observing, Timestamp
-    include Associations, AssociationPreload, NamedScope
+    include Associations, NamedScope
     include IdentityMap
     include ActiveModel::SecurePassword
 
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb b/activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb
index 3716937689..d88720c8bf 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb
@@ -89,6 +89,16 @@ module ActiveRecord
         retrieve_connection
       end
 
+      # Returns the configuration of the associated connection as a hash:
+      #
+      #  ActiveRecord::Base.connection_config
+      #  # => {:pool=>5, :timeout=>5000, :database=>"db/development.sqlite3", :adapter=>"sqlite3"}
+      #
+      # Please use only for reading.
+      def connection_config
+        connection_pool.spec.config
+      end
+
       def connection_pool
         connection_handler.retrieve_connection_pool(self)
       end
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index 49659b3aa5..5de08953f9 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -210,6 +210,10 @@ module ActiveRecord
         @foreign_type ||= options[:foreign_type] || "#{name}_type"
       end
 
+      def type
+        @type ||= "#{options[:as]}_type"
+      end
+
       def primary_key_column
         @primary_key_column ||= klass.columns.find { |c| c.name == klass.primary_key }
       end
@@ -359,6 +363,8 @@ module ActiveRecord
     # Holds all the meta-data about a :through association as it was specified
     # in the Active Record class.
     class ThroughReflection < AssociationReflection #:nodoc:
+      delegate :association_primary_key, :foreign_type, :to => :source_reflection
+
       # Gets the source of the through reflection.  It checks both a singularized
       # and pluralized form for <tt>:belongs_to</tt> or <tt>:has_many</tt>.
       #
@@ -402,10 +408,6 @@ module ActiveRecord
         through_reflection.options
       end
 
-      def association_primary_key
-        source_reflection.association_primary_key
-      end
-
       def check_validity!
         if through_reflection.nil?
           raise HasManyThroughAssociationNotFoundError.new(active_record.name, self)
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index 3c7533ea48..f939bedc81 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -86,7 +86,9 @@ module ActiveRecord
 
       preload = @preload_values
       preload +=  @includes_values unless eager_loading?
-      preload.each {|associations| @klass.send(:preload_associations, @records, associations) }
+      preload.each do |associations|
+        ActiveRecord::Associations::Preloader.new(@records, associations).run
+      end
 
       # @readonly_value is true only if set explicitly. @implicit_readonly is true if there
       # are JOINS and no explicit SELECT.
@@ -190,7 +192,7 @@ module ActiveRecord
         end
 
         stmt = arel.compile_update(Arel.sql(@klass.send(:sanitize_sql_for_assignment, updates)))
-        stmt.take limit
+        stmt.take limit if limit
         stmt.order(*order)
         stmt.key = table[primary_key]
         @klass.connection.update stmt.to_sql
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb
index abc4c54109..c1842b1a96 100644
--- a/activerecord/lib/active_record/relation/calculations.rb
+++ b/activerecord/lib/active_record/relation/calculations.rb
@@ -204,7 +204,19 @@ module ActiveRecord
 
       relation.select_values = [select_value]
 
-      type_cast_calculated_value(@klass.connection.select_value(relation.to_sql), column_for(column_name), operation)
+      query_builder = relation.arel
+
+      if operation == "count"
+        limit  = relation.limit_value
+        offset = relation.offset_value
+
+        unless limit && offset
+          query_builder.limit  = nil
+          query_builder.offset = nil
+        end
+      end
+
+      type_cast_calculated_value(@klass.connection.select_value(query_builder.to_sql), column_for(column_name), operation)
     end
 
     def execute_grouped_calculation(operation, column_name, distinct) #:nodoc:
diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index 7f32e5538e..426000fde1 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -187,7 +187,7 @@ module ActiveRecord
 
     def find_with_associations
       including = (@eager_load_values + @includes_values).uniq
-      join_dependency = ActiveRecord::Associations::ClassMethods::JoinDependency.new(@klass, including, [])
+      join_dependency = ActiveRecord::Associations::JoinDependency.new(@klass, including, [])
       relation = construct_relation_for_association_find(join_dependency)
       rows = connection.select_all(relation.to_sql, 'SQL', relation.bind_values)
       join_dependency.instantiate(rows)
@@ -197,7 +197,7 @@ module ActiveRecord
 
     def construct_relation_for_association_calculations
       including = (@eager_load_values + @includes_values).uniq
-      join_dependency = ActiveRecord::Associations::ClassMethods::JoinDependency.new(@klass, including, arel.froms.first)
+      join_dependency = ActiveRecord::Associations::JoinDependency.new(@klass, including, arel.froms.first)
       relation = except(:includes, :eager_load, :preload)
       apply_join_dependency(relation, join_dependency)
     end
diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb
index f76681e880..cd1d7108b3 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -236,7 +236,7 @@ module ActiveRecord
           'string_join'
         when Hash, Symbol, Array
           'association_join'
-        when ActiveRecord::Associations::ClassMethods::JoinDependency::JoinAssociation
+        when ActiveRecord::Associations::JoinDependency::JoinAssociation
           'stashed_join'
         when Arel::Nodes::Join
           'join_node'
@@ -254,7 +254,7 @@ module ActiveRecord
 
       join_list = custom_join_ast(manager, string_joins)
 
-      join_dependency = ActiveRecord::Associations::ClassMethods::JoinDependency.new(
+      join_dependency = ActiveRecord::Associations::JoinDependency.new(
         @klass,
         association_joins,
         join_list
@@ -284,7 +284,7 @@ module ActiveRecord
         @implicit_readonly = false
         arel.project(*selects)
       else
-        arel.project(Arel.sql(@klass.quoted_table_name + '.*'))
+        arel.project(@klass.arel_table[Arel.star])
       end
     end
 
diff --git a/activerecord/lib/active_record/test_case.rb b/activerecord/lib/active_record/test_case.rb
index 4e711c4884..29efbbcb8c 100644
--- a/activerecord/lib/active_record/test_case.rb
+++ b/activerecord/lib/active_record/test_case.rb
@@ -26,6 +26,7 @@ module ActiveRecord
     def assert_sql(*patterns_to_match)
       $queries_executed = []
       yield
+      $queries_executed
     ensure
       failed_patterns = []
       patterns_to_match.each do |pattern|
diff --git a/activerecord/test/cases/associations/eager_test.rb b/activerecord/test/cases/associations/eager_test.rb
index ca71cd8ed3..48406a9b98 100644
--- a/activerecord/test/cases/associations/eager_test.rb
+++ b/activerecord/test/cases/associations/eager_test.rb
@@ -120,30 +120,29 @@ class EagerAssociationTest < ActiveRecord::TestCase
 
   def test_load_associated_records_in_one_query_when_adapter_has_no_limit
     Post.connection.expects(:in_clause_length).at_least_once.returns(nil)
-    Post.expects(:i_was_called).with([1,2,3,4,5,6,7]).returns([1])
-    associated_records = Post.send(:associated_records, [1,2,3,4,5,6,7]) do |some_ids|
-      Post.i_was_called(some_ids)
+
+    post = posts(:welcome)
+    assert_queries(2) do
+      Post.includes(:comments).where(:id => post.id).to_a
     end
-    assert_equal [1], associated_records
   end
 
   def test_load_associated_records_in_several_queries_when_many_ids_passed
-    Post.connection.expects(:in_clause_length).at_least_once.returns(5)
-    Post.expects(:i_was_called).with([1,2,3,4,5]).returns([1])
-    Post.expects(:i_was_called).with([6,7]).returns([6])
-    associated_records = Post.send(:associated_records, [1,2,3,4,5,6,7]) do |some_ids|
-      Post.i_was_called(some_ids)
+    Post.connection.expects(:in_clause_length).at_least_once.returns(1)
+
+    post1, post2 = posts(:welcome), posts(:thinking)
+    assert_queries(3) do
+      Post.includes(:comments).where(:id => [post1.id, post2.id]).to_a
     end
-    assert_equal [1,6], associated_records
   end
 
   def test_load_associated_records_in_one_query_when_a_few_ids_passed
-    Post.connection.expects(:in_clause_length).at_least_once.returns(5)
-    Post.expects(:i_was_called).with([1,2,3]).returns([1])
-    associated_records = Post.send(:associated_records, [1,2,3]) do |some_ids|
-      Post.i_was_called(some_ids)
+    Post.connection.expects(:in_clause_length).at_least_once.returns(3)
+
+    post = posts(:welcome)
+    assert_queries(2) do
+      Post.includes(:comments).where(:id => post.id).to_a
     end
-    assert_equal [1], associated_records
   end
 
   def test_including_duplicate_objects_from_belongs_to
@@ -526,6 +525,22 @@ class EagerAssociationTest < ActiveRecord::TestCase
     assert posts[1].categories.include?(categories(:general))
   end
 
+  # This is only really relevant when the identity map is off. Since the preloader for habtm
+  # gets raw row hashes from the database and then instantiates them, this test ensures that
+  # it only instantiates one actual object per record from the database.
+  def test_has_and_belongs_to_many_should_not_instantiate_same_records_multiple_times
+    welcome    = posts(:welcome)
+    categories = Category.includes(:posts)
+
+    general    = categories.find { |c| c == categories(:general) }
+    technology = categories.find { |c| c == categories(:technology) }
+
+    post1 = general.posts.to_a.find { |p| p == posts(:welcome) }
+    post2 = technology.posts.to_a.find { |p| p == posts(:welcome) }
+
+    assert_equal post1.object_id, post2.object_id
+  end
+
   def test_eager_with_has_many_and_limit_and_conditions_on_the_eagers
     posts = authors(:david).posts.find(:all,
       :include    => :comments,
diff --git a/activerecord/test/cases/associations/join_model_test.rb b/activerecord/test/cases/associations/join_model_test.rb
index 6d7f905dc5..19303fef9f 100644
--- a/activerecord/test/cases/associations/join_model_test.rb
+++ b/activerecord/test/cases/associations/join_model_test.rb
@@ -214,7 +214,7 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase
   end
 
   def test_has_many_with_piggyback
-    assert_equal "2", categories(:sti_test).authors.first.post_id.to_s
+    assert_equal "2", categories(:sti_test).authors_with_select.first.post_id.to_s
   end
 
   def test_include_has_many_through
diff --git a/activerecord/test/cases/base_test.rb b/activerecord/test/cases/base_test.rb
index ed59b2105d..d03fc68a11 100644
--- a/activerecord/test/cases/base_test.rb
+++ b/activerecord/test/cases/base_test.rb
@@ -134,6 +134,7 @@ class BasicsTest < ActiveRecord::TestCase
     fakepool = Class.new(Struct.new(:spec)) {
       def with_connection; yield self; end
       def connection_pool; self; end
+      def table_exists?(name); false; end
       def quote_table_name(*args); raise "lol quote_table_name"; end
     }
 
diff --git a/activerecord/test/cases/calculations_test.rb b/activerecord/test/cases/calculations_test.rb
index 3121f1615d..caf07a7357 100644
--- a/activerecord/test/cases/calculations_test.rb
+++ b/activerecord/test/cases/calculations_test.rb
@@ -109,6 +109,36 @@ class CalculationsTest < ActiveRecord::TestCase
     assert_equal [2, 6], c.keys.compact
   end
 
+  def test_limit_with_offset_is_kept
+    return if current_adapter?(:OracleAdapter)
+
+    queries = assert_sql { Account.limit(1).offset(1).count }
+    assert_equal 1, queries.length
+    assert_match(/LIMIT/, queries.first)
+    assert_match(/OFFSET/, queries.first)
+  end
+
+  def test_offset_without_limit_removes_offset
+    queries = assert_sql { Account.offset(1).count }
+    assert_equal 1, queries.length
+    assert_no_match(/LIMIT/, queries.first)
+    assert_no_match(/OFFSET/, queries.first)
+  end
+
+  def test_limit_without_offset_removes_limit
+    queries = assert_sql { Account.limit(1).count }
+    assert_equal 1, queries.length
+    assert_no_match(/LIMIT/, queries.first)
+    assert_no_match(/OFFSET/, queries.first)
+  end
+
+  def test_no_limit_no_offset
+    queries = assert_sql { Account.count }
+    assert_equal 1, queries.length
+    assert_no_match(/LIMIT/, queries.first)
+    assert_no_match(/OFFSET/, queries.first)
+  end
+
   def test_should_group_by_summed_field_having_condition
     c = Account.sum(:credit_limit, :group => :firm_id,
                                    :having => 'sum(credit_limit) > 50')
diff --git a/activerecord/test/cases/inheritance_test.rb b/activerecord/test/cases/inheritance_test.rb
index 680d4ca5dd..b5d8314541 100644
--- a/activerecord/test/cases/inheritance_test.rb
+++ b/activerecord/test/cases/inheritance_test.rb
@@ -208,7 +208,7 @@ class InheritanceTest < ActiveRecord::TestCase
 
   def test_eager_load_belongs_to_primary_key_quoting
     con = Account.connection
-    assert_sql(/#{con.quote_table_name('companies')}.#{con.quote_column_name('id')} = 1/) do
+    assert_sql(/#{con.quote_table_name('companies')}.#{con.quote_column_name('id')} IN \(1\)/) do
       Account.find(1, :include => :firm)
     end
   end
diff --git a/activerecord/test/cases/pooled_connections_test.rb b/activerecord/test/cases/pooled_connections_test.rb
index 6269437b14..379cf5b44e 100644
--- a/activerecord/test/cases/pooled_connections_test.rb
+++ b/activerecord/test/cases/pooled_connections_test.rb
@@ -94,6 +94,11 @@ class PooledConnectionsTest < ActiveRecord::TestCase
     ActiveRecord::Base.connection_handler = old_handler
   end
 
+  def test_connection_config
+    ActiveRecord::Base.establish_connection(@connection)
+    assert_equal @connection, ActiveRecord::Base.connection_config
+  end
+
   def test_with_connection_nesting_safety
     ActiveRecord::Base.establish_connection(@connection.merge({:pool => 1, :wait_timeout => 0.1}))
 
diff --git a/activerecord/test/models/category.rb b/activerecord/test/models/category.rb
index 06908ea85e..8f37433ec6 100644
--- a/activerecord/test/models/category.rb
+++ b/activerecord/test/models/category.rb
@@ -22,7 +22,8 @@ class Category < ActiveRecord::Base
   end
 
   has_many :categorizations
-  has_many :authors, :through => :categorizations, :select => 'authors.*, categorizations.post_id'
+  has_many :authors, :through => :categorizations
+  has_many :authors_with_select, :through => :categorizations, :source => :author, :select => 'authors.*, categorizations.post_id'
 
   scope :general, :conditions => { :name => 'General' }
 end
diff --git a/activesupport/CHANGELOG b/activesupport/CHANGELOG
index 1b8bcf649c..373236ce9a 100644
--- a/activesupport/CHANGELOG
+++ b/activesupport/CHANGELOG
@@ -1,5 +1,14 @@
 *Rails 3.1.0 (unreleased)*
 
+* LocalCache strategy is now a real middleware class, not an anonymous class
+posing for pictures.
+
+* ActiveSupport::Dependencies::ClassCache class has been introduced for
+holding references to reloadable classes.
+
+* ActiveSupport::Dependencies::Reference has been refactored to take direct
+advantage of the new ClassCache.
+
 * Backports Range#cover? as an alias for Range#include? in Ruby 1.8 [Diego Carrion, fxn]
 
 * Added weeks_ago and prev_week to Date/DateTime/Time. [Rob Zolkos, fxn]
diff --git a/activesupport/lib/active_support/cache/strategy/local_cache.rb b/activesupport/lib/active_support/cache/strategy/local_cache.rb
index 4dce35f1c9..0649a058aa 100644
--- a/activesupport/lib/active_support/cache/strategy/local_cache.rb
+++ b/activesupport/lib/active_support/cache/strategy/local_cache.rb
@@ -50,34 +50,39 @@ module ActiveSupport
           end
         end
 
-        # Middleware class can be inserted as a Rack handler to be local cache for the
-        # duration of request.
-        def middleware
-          @middleware ||= begin
-            klass = Class.new
-            klass.class_eval(<<-EOS, __FILE__, __LINE__ + 1)
-              class << self
-                def name
-                  "ActiveSupport::Cache::Strategy::LocalCache"
-                end
-                alias :to_s :name
-              end
+        #--
+        # This class wraps up local storage for middlewares. Only the middleware method should
+        # construct them.
+        class Middleware # :nodoc:
+          attr_reader :name, :thread_local_key
 
-              def initialize(app)
-                @app = app
-              end
+          def initialize(name, thread_local_key)
+            @name             = name
+            @thread_local_key = thread_local_key
+            @app              = nil
+          end
 
-              def call(env)
-                Thread.current[:#{thread_local_key}] = LocalStore.new
-                @app.call(env)
-              ensure
-                Thread.current[:#{thread_local_key}] = nil
-              end
-            EOS
-            klass
+          def new(app)
+            @app = app
+            self
+          end
+
+          def call(env)
+            Thread.current[thread_local_key] = LocalStore.new
+            @app.call(env)
+          ensure
+            Thread.current[thread_local_key] = nil
           end
         end
 
+        # Middleware class can be inserted as a Rack handler to be local cache for the
+        # duration of request.
+        def middleware
+          @middleware ||= Middleware.new(
+            "ActiveSupport::Cache::Strategy::LocalCache",
+            thread_local_key)
+        end
+
         def clear(options = nil) # :nodoc:
           local_cache.clear(options) if local_cache
           super
diff --git a/activesupport/lib/active_support/configurable.rb b/activesupport/lib/active_support/configurable.rb
index 644db0b205..be19189c04 100644
--- a/activesupport/lib/active_support/configurable.rb
+++ b/activesupport/lib/active_support/configurable.rb
@@ -26,7 +26,7 @@ module ActiveSupport
 
     module ClassMethods
       def config
-        @_config ||= if superclass.respond_to?(:config)
+        @_config ||= if respond_to?(:superclass) && superclass.respond_to?(:config)
           superclass.config.inheritable_copy
         else
           # create a new "anonymous" class that will host the compiled reader methods
diff --git a/activesupport/lib/active_support/core_ext/date/calculations.rb b/activesupport/lib/active_support/core_ext/date/calculations.rb
index f34185f22c..724e076407 100644
--- a/activesupport/lib/active_support/core_ext/date/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date/calculations.rb
@@ -36,9 +36,9 @@ class Date
       ::Date.current.tomorrow
     end
 
-    # Returns Time.zone.today when config.time_zone is set, otherwise just returns Date.today.
+    # Returns Time.zone.today when <tt>Time.zone</tt> or <tt>config.time_zone</tt> are set, otherwise just returns Date.today.
     def current
-      ::Time.zone_default ? ::Time.zone.today : ::Date.today
+      ::Time.zone ? ::Time.zone.today : ::Date.today
     end
   end
 
diff --git a/activesupport/lib/active_support/core_ext/date/zones.rb b/activesupport/lib/active_support/core_ext/date/zones.rb
index 3a83af6be2..a70b47b7bc 100644
--- a/activesupport/lib/active_support/core_ext/date/zones.rb
+++ b/activesupport/lib/active_support/core_ext/date/zones.rb
@@ -2,10 +2,10 @@ require 'date'
 require 'active_support/core_ext/time/zones'
 
 class Date
-  # Converts Date to a TimeWithZone in the current zone if Time.zone_default is set,
-  # otherwise converts Date to a Time via Date#to_time
+  # Converts Date to a TimeWithZone in the current zone if Time.zone or Time.zone_default
+  # is set, otherwise converts Date to a Time via Date#to_time
   def to_time_in_current_zone
-    if ::Time.zone_default
+    if ::Time.zone
       ::Time.zone.local(year, month, day)
     else
       to_time
diff --git a/activesupport/lib/active_support/core_ext/date_time/calculations.rb b/activesupport/lib/active_support/core_ext/date_time/calculations.rb
index 1dc3933e12..8d924ad420 100644
--- a/activesupport/lib/active_support/core_ext/date_time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date_time/calculations.rb
@@ -1,6 +1,4 @@
 require 'rational' unless RUBY_VERSION >= '1.9.2'
-require 'active_support/core_ext/object/acts_like'
-require 'active_support/core_ext/time/zones'
 
 class DateTime
   class << self
@@ -9,8 +7,9 @@ class DateTime
       ::Time.local(2007).utc_offset.to_r / 86400
     end
 
+    # Returns <tt>Time.zone.now.to_datetime</tt> when <tt>Time.zone</tt> or <tt>config.time_zone</tt> are set, otherwise returns <tt>Time.now.to_datetime</tt>.
     def current
-      ::Time.zone_default ? ::Time.zone.now.to_datetime : ::Time.now.to_datetime
+      ::Time.zone ? ::Time.zone.now.to_datetime : ::Time.now.to_datetime
     end
   end
 
@@ -104,11 +103,7 @@ class DateTime
   end
 
   # Layers additional behavior on DateTime#<=> so that Time and ActiveSupport::TimeWithZone instances can be compared with a DateTime
-  def compare_with_coercion(other)
-    other = other.comparable_time if other.respond_to?(:comparable_time)
-    other = other.to_datetime unless other.acts_like?(:date)
-    compare_without_coercion(other)
+  def <=>(other)
+    super other.to_datetime
   end
-  alias_method :compare_without_coercion, :<=>
-  alias_method :<=>, :compare_with_coercion
 end
diff --git a/activesupport/lib/active_support/core_ext/hash/reverse_merge.rb b/activesupport/lib/active_support/core_ext/hash/reverse_merge.rb
index 87a7bebd7b..63b4ba49e9 100644
--- a/activesupport/lib/active_support/core_ext/hash/reverse_merge.rb
+++ b/activesupport/lib/active_support/core_ext/hash/reverse_merge.rb
@@ -1,11 +1,9 @@
 class Hash
-  # Allows for reverse merging two hashes where the keys in the calling hash take precedence over those
-  # in the <tt>other_hash</tt>. This is particularly useful for initializing an option hash with default values:
+  # Merges the caller into +other_hash+. For example,
   #
-  #   def setup(options = {})
-  #     options.reverse_merge! :size => 25, :velocity => 10
-  #   end
+  #   options = options.reverse_merge(:size => 25, :velocity => 10)
   #
+<<<<<<< HEAD
   # The default <tt>:size</tt> and <tt>:velocity</tt> are only set if the +options+ hash passed in doesn't already
   # have the respective key.
   #
@@ -14,12 +12,19 @@ class Hash
   #   def setup(options = {})
   #     options = { :size => 25, :velocity => 10 }.merge(options)
   #   end
+=======
+  # is equivalent to
+  #
+  #   options = {:size => 25, :velocity => 10}.merge(options)
+  #
+  # This is particularly useful for initializing an options hash
+  # with default values.
+>>>>>>> 20768176292cbcb883ab152b4aa9ed8c664771cd
   def reverse_merge(other_hash)
     other_hash.merge(self)
   end
 
-  # Performs the opposite of <tt>merge</tt>, with the keys and values from the first hash taking precedence over the second.
-  # Modifies the receiver in place.
+  # Destructive +reverse_merge+.
   def reverse_merge!(other_hash)
     # right wins if there is no left
     merge!( other_hash ){|key,left,right| left }
diff --git a/activesupport/lib/active_support/core_ext/object/blank.rb b/activesupport/lib/active_support/core_ext/object/blank.rb
index f70853073a..7b5832b51a 100644
--- a/activesupport/lib/active_support/core_ext/object/blank.rb
+++ b/activesupport/lib/active_support/core_ext/object/blank.rb
@@ -13,7 +13,11 @@ class Object
     respond_to?(:empty?) ? empty? : !self
   end
 
+<<<<<<< HEAD
   # An object is present if it's not #blank?.
+=======
+  # An object is present if it's not <tt>blank?</tt>.
+>>>>>>> 20768176292cbcb883ab152b4aa9ed8c664771cd
   def present?
     !blank?
   end
diff --git a/activesupport/lib/active_support/core_ext/time/calculations.rb b/activesupport/lib/active_support/core_ext/time/calculations.rb
index fa052fa86b..7e134db118 100644
--- a/activesupport/lib/active_support/core_ext/time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/time/calculations.rb
@@ -1,7 +1,4 @@
 require 'active_support/duration'
-require 'active_support/core_ext/date/acts_like'
-require 'active_support/core_ext/date/calculations'
-require 'active_support/core_ext/date_time/conversions'
 
 class Time
   COMMON_YEAR_DAYS_IN_MONTH = [nil, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
@@ -41,9 +38,9 @@ class Time
       time_with_datetime_fallback(:local, *args)
     end
 
-    # Returns <tt>Time.zone.now</tt> when <tt>config.time_zone</tt> is set, otherwise just returns <tt>Time.now</tt>.
+    # Returns <tt>Time.zone.now</tt> when <tt>Time.zone</tt> or <tt>config.time_zone</tt> are set, otherwise just returns <tt>Time.now</tt>.
     def current
-      ::Time.zone_default ? ::Time.zone.now : ::Time.now
+      ::Time.zone ? ::Time.zone.now : ::Time.now
     end
   end
 
@@ -283,14 +280,8 @@ class Time
   # Layers additional behavior on Time#<=> so that DateTime and ActiveSupport::TimeWithZone instances
   # can be chronologically compared with a Time
   def compare_with_coercion(other)
-    # if other is an ActiveSupport::TimeWithZone, coerce a Time instance from it so we can do <=> comparison
-    other = other.comparable_time if other.respond_to?(:comparable_time)
-    if other.acts_like?(:date)
-      # other is a Date/DateTime, so coerce self #to_datetime and hand off to DateTime#<=>
-      to_datetime.compare_without_coercion(other)
-    else
-      compare_without_coercion(other)
-    end
+    # we're avoiding Time#to_datetime cause it's expensive
+    other.is_a?(Time) ? compare_without_coercion(other.to_time) : to_datetime <=> other
   end
   alias_method :compare_without_coercion, :<=>
   alias_method :<=>, :compare_with_coercion
diff --git a/activesupport/lib/active_support/dependencies.rb b/activesupport/lib/active_support/dependencies.rb
index daa98162d0..dc10f78104 100644
--- a/activesupport/lib/active_support/dependencies.rb
+++ b/activesupport/lib/active_support/dependencies.rb
@@ -5,6 +5,7 @@ require 'active_support/core_ext/module/aliasing'
 require 'active_support/core_ext/module/attribute_accessors'
 require 'active_support/core_ext/module/introspection'
 require 'active_support/core_ext/module/anonymous'
+require 'active_support/core_ext/module/deprecation'
 require 'active_support/core_ext/object/blank'
 require 'active_support/core_ext/load_error'
 require 'active_support/core_ext/name_error'
@@ -47,9 +48,6 @@ module ActiveSupport #:nodoc:
     mattr_accessor :autoloaded_constants
     self.autoloaded_constants = []
 
-    mattr_accessor :references
-    self.references = {}
-
     # An array of constant names that need to be unloaded on every request. Used
     # to allow arbitrary constants to be marked for unloading.
     mattr_accessor :explicitly_unloadable_constants
@@ -524,31 +522,76 @@ module ActiveSupport #:nodoc:
       explicitly_unloadable_constants.each { |const| remove_constant const }
     end
 
-    class Reference
-      @@constants = Hash.new { |h, k| h[k] = Inflector.constantize(k) }
+    class ClassCache
+      def initialize
+        @store = Hash.new { |h, k| h[k] = Inflector.constantize(k) }
+      end
+
+      def empty?
+        @store.empty?
+      end
+
+      def key?(key)
+        @store.key?(key)
+      end
+
+      def []=(key, value)
+        return unless key.respond_to?(:name)
+
+        raise(ArgumentError, 'anonymous classes cannot be cached') if key.name.blank?
+
+        @store[key.name] = value
+      end
+
+      def [](key)
+        key = key.name if key.respond_to?(:name)
+
+        @store[key]
+      end
+      alias :get :[]
 
-      attr_reader :name
+      class Getter # :nodoc:
+        def initialize(name)
+          @name = name
+        end
 
-      def initialize(name)
-        @name = name.to_s
-        @@constants[@name] = name if name.respond_to?(:name)
+        def get
+          Reference.get @name
+        end
+        deprecate :get
       end
 
-      def get
-        @@constants[@name]
+      def new(name)
+        self[name] = name
+        Getter.new(name)
       end
+      deprecate :new
 
-      def self.clear!
-        @@constants.clear
+      def store(name)
+        self[name] = name
+        self
+      end
+
+      def clear!
+        @store.clear
       end
     end
 
+    Reference = ClassCache.new
+
     def ref(name)
-      references[name] ||= Reference.new(name)
+      Reference.new(name)
+    end
+    deprecate :ref
+
+    # Store a reference to a class +klass+.
+    def reference(klass)
+      Reference.store klass
     end
 
+    # Get the reference for class named +name+.
     def constantize(name)
-      ref(name).get
+      Reference.get(name)
     end
 
     # Determine if the given constant has been automatically loaded.
diff --git a/activesupport/lib/active_support/ordered_options.rb b/activesupport/lib/active_support/ordered_options.rb
index f4c27ac935..8d8e6ebc58 100644
--- a/activesupport/lib/active_support/ordered_options.rb
+++ b/activesupport/lib/active_support/ordered_options.rb
@@ -31,7 +31,7 @@ module ActiveSupport #:nodoc:
 
     def method_missing(name, *args)
       if name.to_s =~ /(.*)=$/
-        self[$1.to_sym] = args.first
+        self[$1] = args.first
       else
         self[name]
       end
diff --git a/activesupport/lib/active_support/time_with_zone.rb b/activesupport/lib/active_support/time_with_zone.rb
index 3da216ac78..c66aa78ce8 100644
--- a/activesupport/lib/active_support/time_with_zone.rb
+++ b/activesupport/lib/active_support/time_with_zone.rb
@@ -281,7 +281,7 @@ module ActiveSupport
 
     # A TimeWithZone acts like a Time, so just return +self+.
     def to_time
-      self
+      utc
     end
 
     def to_datetime
diff --git a/activesupport/test/class_cache_test.rb b/activesupport/test/class_cache_test.rb
new file mode 100644
index 0000000000..8445af8d25
--- /dev/null
+++ b/activesupport/test/class_cache_test.rb
@@ -0,0 +1,108 @@
+require 'abstract_unit'
+require 'active_support/dependencies'
+
+module ActiveSupport
+  module Dependencies
+    class ClassCacheTest < ActiveSupport::TestCase
+      def setup
+        @cache = ClassCache.new
+      end
+
+      def test_empty?
+        assert @cache.empty?
+        @cache[ClassCacheTest] = ClassCacheTest
+        assert !@cache.empty?
+      end
+
+      def test_clear!
+        assert @cache.empty?
+        @cache[ClassCacheTest] = ClassCacheTest
+        assert !@cache.empty?
+        @cache.clear!
+        assert @cache.empty?
+      end
+
+      def test_set_key
+        @cache[ClassCacheTest] = ClassCacheTest
+        assert @cache.key?(ClassCacheTest.name)
+      end
+
+      def test_set_rejects_strings
+        @cache[ClassCacheTest.name] = ClassCacheTest
+        assert @cache.empty?
+      end
+
+      def test_get_with_class
+        @cache[ClassCacheTest] = ClassCacheTest
+        assert_equal ClassCacheTest, @cache[ClassCacheTest]
+      end
+
+      def test_get_with_name
+        @cache[ClassCacheTest] = ClassCacheTest
+        assert_equal ClassCacheTest, @cache[ClassCacheTest.name]
+      end
+
+      def test_get_constantizes
+        assert @cache.empty?
+        assert_equal ClassCacheTest, @cache[ClassCacheTest.name]
+      end
+
+      def test_get_is_an_alias
+        assert_equal @cache[ClassCacheTest], @cache.get(ClassCacheTest.name)
+      end
+
+      def test_new
+        assert_deprecated do
+          @cache.new ClassCacheTest
+        end
+        assert @cache.key?(ClassCacheTest.name)
+      end
+
+      def test_new_rejects_strings
+        assert_deprecated do
+          @cache.new ClassCacheTest.name
+        end
+        assert !@cache.key?(ClassCacheTest.name)
+      end
+
+      def test_new_rejects_strings
+        @cache.store ClassCacheTest.name
+        assert !@cache.key?(ClassCacheTest.name)
+      end
+
+      def test_store_returns_self
+        x = @cache.store ClassCacheTest
+        assert_equal @cache, x
+      end
+
+      def test_new_returns_proxy
+        v = nil
+        assert_deprecated do
+          v = @cache.new ClassCacheTest.name
+        end
+
+        assert_deprecated do
+          assert_equal ClassCacheTest, v.get
+        end
+      end
+
+      def test_anonymous_class_fail
+        assert_raises(ArgumentError) do
+          assert_deprecated do
+            @cache.new Class.new
+          end
+        end
+
+        assert_raises(ArgumentError) do
+          x = Class.new
+          @cache[x] = x
+        end
+
+        assert_raises(ArgumentError) do
+          x = Class.new
+          @cache.store x
+        end
+      end
+    end
+  end
+end
diff --git a/activesupport/test/configurable_test.rb b/activesupport/test/configurable_test.rb
index 9c773c1944..2b28e61815 100644
--- a/activesupport/test/configurable_test.rb
+++ b/activesupport/test/configurable_test.rb
@@ -21,6 +21,12 @@ class ConfigurableActiveSupport < ActiveSupport::TestCase
     assert_equal({ :foo => :bar }, Parent.config)
   end
 
+  test "adds a configuration hash to a module as well" do
+    mixin = Module.new { include ActiveSupport::Configurable }
+    mixin.config.foo = :bar
+    assert_equal({ :foo => :bar }, mixin.config)
+  end
+
   test "configuration hash is inheritable" do
     assert_equal :bar, Child.config.foo
     assert_equal :bar, Parent.config.foo
@@ -57,4 +63,4 @@ class ConfigurableActiveSupport < ActiveSupport::TestCase
     assert_respond_to child.config, :bar
     assert_respond_to child.new.config, :bar
   end
-end
\ No newline at end of file
+end
diff --git a/activesupport/test/core_ext/date_ext_test.rb b/activesupport/test/core_ext/date_ext_test.rb
index b4d7633e5f..03b84ae2e5 100644
--- a/activesupport/test/core_ext/date_ext_test.rb
+++ b/activesupport/test/core_ext/date_ext_test.rb
@@ -259,7 +259,7 @@ class DateExtCalculationsTest < ActiveSupport::TestCase
     assert_equal Date.current - 1, Date.yesterday
   end
 
-  def test_yesterday_constructor_when_zone_default_is_not_set
+  def test_yesterday_constructor_when_zone_is_not_set
     with_env_tz 'UTC' do
       with_tz_default do
         Time.stubs(:now).returns Time.local(2000, 1, 1)
@@ -268,7 +268,7 @@ class DateExtCalculationsTest < ActiveSupport::TestCase
     end
   end
 
-  def test_yesterday_constructor_when_zone_default_is_set
+  def test_yesterday_constructor_when_zone_is_set
     with_env_tz 'UTC' do
       with_tz_default ActiveSupport::TimeZone['Eastern Time (US & Canada)'] do # UTC -5
         Time.stubs(:now).returns Time.local(2000, 1, 1)
@@ -281,7 +281,7 @@ class DateExtCalculationsTest < ActiveSupport::TestCase
     assert_equal Date.current + 1, Date.tomorrow
   end
 
-  def test_tomorrow_constructor_when_zone_default_is_not_set
+  def test_tomorrow_constructor_when_zone_is_not_set
     with_env_tz 'UTC' do
       with_tz_default do
         Time.stubs(:now).returns Time.local(1999, 12, 31)
@@ -290,7 +290,7 @@ class DateExtCalculationsTest < ActiveSupport::TestCase
     end
   end
 
-  def test_tomorrow_constructor_when_zone_default_is_set
+  def test_tomorrow_constructor_when_zone_is_set
     with_env_tz 'UTC' do
       with_tz_default ActiveSupport::TimeZone['Europe/Paris'] do # UTC +1
         Time.stubs(:now).returns Time.local(1999, 12, 31, 23)
@@ -303,7 +303,7 @@ class DateExtCalculationsTest < ActiveSupport::TestCase
     assert_equal Time.local(2005,2,21,0,0,45), Date.new(2005,2,21).since(45)
   end
 
-  def test_since_when_zone_default_is_set
+  def test_since_when_zone_is_set
     zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
     with_env_tz 'UTC' do
       with_tz_default zone do
@@ -317,7 +317,7 @@ class DateExtCalculationsTest < ActiveSupport::TestCase
     assert_equal Time.local(2005,2,20,23,59,15), Date.new(2005,2,21).ago(45)
   end
 
-  def test_ago_when_zone_default_is_set
+  def test_ago_when_zone_is_set
     zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
     with_env_tz 'UTC' do
       with_tz_default zone do
@@ -331,7 +331,7 @@ class DateExtCalculationsTest < ActiveSupport::TestCase
     assert_equal Time.local(2005,2,21,0,0,0), Date.new(2005,2,21).beginning_of_day
   end
 
-  def test_beginning_of_day_when_zone_default_is_set
+  def test_beginning_of_day_when_zone_is_set
     zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
     with_env_tz 'UTC' do
       with_tz_default zone do
@@ -345,7 +345,7 @@ class DateExtCalculationsTest < ActiveSupport::TestCase
     assert_equal Time.local(2005,2,21,23,59,59,999999.999), Date.new(2005,2,21).end_of_day
   end
 
-  def test_end_of_day_when_zone_default_is_set
+  def test_end_of_day_when_zone_is_set
     zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
     with_env_tz 'UTC' do
       with_tz_default zone do
@@ -367,7 +367,7 @@ class DateExtCalculationsTest < ActiveSupport::TestCase
     end
   end
 
-  def test_xmlschema_when_zone_default_is_set
+  def test_xmlschema_when_zone_is_set
     with_env_tz 'UTC' do
       with_tz_default ActiveSupport::TimeZone['Eastern Time (US & Canada)'] do # UTC -5
         assert_match(/^1980-02-28T00:00:00-05:?00$/, Date.new(1980, 2, 28).xmlschema)
@@ -407,7 +407,7 @@ class DateExtCalculationsTest < ActiveSupport::TestCase
     assert_equal true, Date.new(2000,1,2).future?
   end
 
-  def test_current_returns_date_today_when_zone_default_not_set
+  def test_current_returns_date_today_when_zone_not_set
     with_env_tz 'US/Central' do
       Time.stubs(:now).returns Time.local(1999, 12, 31, 23)
       assert_equal Date.new(1999, 12, 31), Date.today
@@ -415,15 +415,15 @@ class DateExtCalculationsTest < ActiveSupport::TestCase
     end
   end
 
-  def test_current_returns_time_zone_today_when_zone_default_set
-    Time.zone_default = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
+  def test_current_returns_time_zone_today_when_zone_is_set
+    Time.zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
     with_env_tz 'US/Central' do
       Time.stubs(:now).returns Time.local(1999, 12, 31, 23)
       assert_equal Date.new(1999, 12, 31), Date.today
       assert_equal Date.new(2000, 1, 1), Date.current
     end
   ensure
-    Time.zone_default = nil
+    Time.zone = nil
   end
 
   def test_date_advance_should_not_change_passed_options_hash
@@ -441,11 +441,11 @@ class DateExtCalculationsTest < ActiveSupport::TestCase
     end
 
     def with_tz_default(tz = nil)
-      old_tz = Time.zone_default
-      Time.zone_default = tz
+      old_tz = Time.zone
+      Time.zone = tz
       yield
     ensure
-      Time.zone_default = old_tz
+      Time.zone = old_tz
     end
 end
 
diff --git a/activesupport/test/core_ext/date_time_ext_test.rb b/activesupport/test/core_ext/date_time_ext_test.rb
index 8edb95b63a..456736cbad 100644
--- a/activesupport/test/core_ext/date_time_ext_test.rb
+++ b/activesupport/test/core_ext/date_time_ext_test.rb
@@ -282,21 +282,21 @@ class DateTimeExtCalculationsTest < Test::Unit::TestCase
     assert_equal true,  DateTime.civil(2005,2,10,20,30,46).future?
   end
 
-  def test_current_returns_date_today_when_zone_default_not_set
+  def test_current_returns_date_today_when_zone_is_not_set
     with_env_tz 'US/Eastern' do
       Time.stubs(:now).returns Time.local(1999, 12, 31, 23, 59, 59)
       assert_equal DateTime.new(1999, 12, 31, 23, 59, 59, Rational(-18000, 86400)), DateTime.current
     end
   end
 
-  def test_current_returns_time_zone_today_when_zone_default_set
-    Time.zone_default = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
+  def test_current_returns_time_zone_today_when_zone_is_set
+    Time.zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
     with_env_tz 'US/Eastern' do
       Time.stubs(:now).returns Time.local(1999, 12, 31, 23, 59, 59)
       assert_equal DateTime.new(1999, 12, 31, 23, 59, 59, Rational(-18000, 86400)), DateTime.current
     end
   ensure
-    Time.zone_default = nil
+    Time.zone = nil
   end
 
   def test_current_without_time_zone
diff --git a/activesupport/test/core_ext/duration_test.rb b/activesupport/test/core_ext/duration_test.rb
index 6a01eeed6b..c0b529d9f8 100644
--- a/activesupport/test/core_ext/duration_test.rb
+++ b/activesupport/test/core_ext/duration_test.rb
@@ -89,8 +89,8 @@ class DurationTest < ActiveSupport::TestCase
     assert_in_delta((7 * 24 * 1.7).hours.ago(t), 1.7.weeks.ago(t), 1)
   end
 
-  def test_since_and_ago_anchored_to_time_now_when_time_zone_default_not_set
-    Time.zone_default = nil
+  def test_since_and_ago_anchored_to_time_now_when_time_zone_is_not_set
+    Time.zone = nil
     with_env_tz 'US/Eastern' do
       Time.stubs(:now).returns Time.local(2000)
       # since
@@ -102,8 +102,8 @@ class DurationTest < ActiveSupport::TestCase
     end
   end
 
-  def test_since_and_ago_anchored_to_time_zone_now_when_time_zone_default_set
-    Time.zone_default = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
+  def test_since_and_ago_anchored_to_time_zone_now_when_time_zone_is_set
+    Time.zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
     with_env_tz 'US/Eastern' do
       Time.stubs(:now).returns Time.local(2000)
       # since
@@ -116,7 +116,7 @@ class DurationTest < ActiveSupport::TestCase
       assert_equal 'Eastern Time (US & Canada)', 5.seconds.ago.time_zone.name
     end
   ensure
-    Time.zone_default = nil
+    Time.zone = nil
   end
 
   def test_adding_hours_across_dst_boundary
diff --git a/activesupport/test/core_ext/numeric_ext_test.rb b/activesupport/test/core_ext/numeric_ext_test.rb
index 6ef4e37b26..3a2452b4b0 100644
--- a/activesupport/test/core_ext/numeric_ext_test.rb
+++ b/activesupport/test/core_ext/numeric_ext_test.rb
@@ -89,8 +89,8 @@ class NumericExtTimeAndDateTimeTest < Test::Unit::TestCase
     assert_equal DateTime.civil(2005,2,28,15,15,10), DateTime.civil(2004,2,29,15,15,10) + 1.year
   end
 
-  def test_since_and_ago_anchored_to_time_now_when_time_zone_default_not_set
-    Time.zone_default = nil
+  def test_since_and_ago_anchored_to_time_now_when_time_zone_is_not_set
+    Time.zone = nil
     with_env_tz 'US/Eastern' do
       Time.stubs(:now).returns Time.local(2000)
       # since
@@ -102,8 +102,8 @@ class NumericExtTimeAndDateTimeTest < Test::Unit::TestCase
     end
   end
 
-  def test_since_and_ago_anchored_to_time_zone_now_when_time_zone_default_set
-    Time.zone_default = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
+  def test_since_and_ago_anchored_to_time_zone_now_when_time_zone_is_set
+    Time.zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
     with_env_tz 'US/Eastern' do
       Time.stubs(:now).returns Time.local(2000)
       # since
@@ -116,7 +116,7 @@ class NumericExtTimeAndDateTimeTest < Test::Unit::TestCase
       assert_equal 'Eastern Time (US & Canada)', 5.ago.time_zone.name
     end
   ensure
-    Time.zone_default = nil
+    Time.zone = nil
   end
 
   protected
diff --git a/activesupport/test/core_ext/time_ext_test.rb b/activesupport/test/core_ext/time_ext_test.rb
index 891a6badac..53d497013a 100644
--- a/activesupport/test/core_ext/time_ext_test.rb
+++ b/activesupport/test/core_ext/time_ext_test.rb
@@ -533,9 +533,19 @@ class TimeExtCalculationsTest < ActiveSupport::TestCase
     Time::DATE_FORMATS.delete(:custom)
   end
 
-  def test_conversion_methods_are_publicized
-    assert Time.public_instance_methods.include?(:to_date)     || Time.public_instance_methods.include?('to_date')
-    assert Time.public_instance_methods.include?(:to_datetime) || Time.public_instance_methods.include?('to_datetime')
+  def test_to_date
+    assert_equal Date.new(2005, 2, 21), Time.local(2005, 2, 21, 17, 44, 30).to_date
+  end
+
+  def test_to_datetime
+    assert_equal Time.utc(2005, 2, 21, 17, 44, 30).to_datetime, DateTime.civil(2005, 2, 21, 17, 44, 30, 0, 0)
+    with_env_tz 'US/Eastern' do
+      assert_equal Time.local(2005, 2, 21, 17, 44, 30).to_datetime, DateTime.civil(2005, 2, 21, 17, 44, 30, Rational(Time.local(2005, 2, 21, 17, 44, 30).utc_offset, 86400), 0)
+    end
+    with_env_tz 'NZ' do
+      assert_equal Time.local(2005, 2, 21, 17, 44, 30).to_datetime, DateTime.civil(2005, 2, 21, 17, 44, 30, Rational(Time.local(2005, 2, 21, 17, 44, 30).utc_offset, 86400), 0)
+    end
+    assert_equal ::Date::ITALY, Time.utc(2005, 2, 21, 17, 44, 30).to_datetime.start # use Ruby's default start value
   end
 
   def test_to_time
diff --git a/activesupport/test/core_ext/time_with_zone_test.rb b/activesupport/test/core_ext/time_with_zone_test.rb
index 5c226c2d09..bafa335a09 100644
--- a/activesupport/test/core_ext/time_with_zone_test.rb
+++ b/activesupport/test/core_ext/time_with_zone_test.rb
@@ -768,10 +768,10 @@ class TimeWithZoneMethodsForTimeAndDateTimeTest < Test::Unit::TestCase
   end
 
   def test_localtime
-    Time.zone_default = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
+    Time.zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
     assert_equal @dt.in_time_zone.localtime, @dt.in_time_zone.utc.to_time.getlocal
   ensure
-    Time.zone_default = nil
+    Time.zone = nil
   end
 
   def test_use_zone
@@ -801,7 +801,7 @@ class TimeWithZoneMethodsForTimeAndDateTimeTest < Test::Unit::TestCase
     assert_equal nil, Time.zone
   end
 
-  def test_time_zone_getter_and_setter_with_zone_default
+  def test_time_zone_getter_and_setter_with_zone_default_set
     Time.zone_default = ActiveSupport::TimeZone['Alaska']
     assert_equal ActiveSupport::TimeZone['Alaska'], Time.zone
     Time.zone = ActiveSupport::TimeZone['Hawaii']
@@ -809,6 +809,7 @@ class TimeWithZoneMethodsForTimeAndDateTimeTest < Test::Unit::TestCase
     Time.zone = nil
     assert_equal ActiveSupport::TimeZone['Alaska'], Time.zone
   ensure
+    Time.zone = nil
     Time.zone_default = nil
   end
 
@@ -849,7 +850,7 @@ class TimeWithZoneMethodsForTimeAndDateTimeTest < Test::Unit::TestCase
     assert_nil Time.zone
   end
 
-  def test_current_returns_time_now_when_zone_default_not_set
+  def test_current_returns_time_now_when_zone_not_set
     with_env_tz 'US/Eastern' do
       Time.stubs(:now).returns Time.local(2000)
       assert_equal false, Time.current.is_a?(ActiveSupport::TimeWithZone)
@@ -857,8 +858,8 @@ class TimeWithZoneMethodsForTimeAndDateTimeTest < Test::Unit::TestCase
     end
   end
 
-  def test_current_returns_time_zone_now_when_zone_default_set
-    Time.zone_default = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
+  def test_current_returns_time_zone_now_when_zone_set
+    Time.zone = ActiveSupport::TimeZone['Eastern Time (US & Canada)']
     with_env_tz 'US/Eastern' do
       Time.stubs(:now).returns Time.local(2000)
       assert_equal true, Time.current.is_a?(ActiveSupport::TimeWithZone)
@@ -866,7 +867,7 @@ class TimeWithZoneMethodsForTimeAndDateTimeTest < Test::Unit::TestCase
       assert_equal Time.utc(2000), Time.current.time
     end
   ensure
-    Time.zone_default = nil
+    Time.zone = nil
   end
 
   protected
diff --git a/activesupport/test/dependencies_test.rb b/activesupport/test/dependencies_test.rb
index bc7f597f1d..ef017d7436 100644
--- a/activesupport/test/dependencies_test.rb
+++ b/activesupport/test/dependencies_test.rb
@@ -477,15 +477,15 @@ class DependenciesTest < Test::Unit::TestCase
 
   def test_references_should_work
     with_loading 'dependencies' do
-      c = ActiveSupport::Dependencies.ref("ServiceOne")
+      c = ActiveSupport::Dependencies.reference("ServiceOne")
       service_one_first = ServiceOne
-      assert_equal service_one_first, c.get
+      assert_equal service_one_first, c.get("ServiceOne")
       ActiveSupport::Dependencies.clear
       assert ! defined?(ServiceOne)
 
       service_one_second = ServiceOne
-      assert_not_equal service_one_first, c.get
-      assert_equal service_one_second, c.get
+      assert_not_equal service_one_first, c.get("ServiceOne")
+      assert_equal service_one_second, c.get("ServiceOne")
     end
   end
 
diff --git a/activesupport/test/inflector_test.rb b/activesupport/test/inflector_test.rb
index f55116dfab..1670d9ee7d 100644
--- a/activesupport/test/inflector_test.rb
+++ b/activesupport/test/inflector_test.rb
@@ -51,21 +51,21 @@ class InflectorTest < Test::Unit::TestCase
   end
 
   SingularToPlural.each do |singular, plural|
-    define_method "test_pluralize_#{singular}" do
+    define_method "test_pluralize_singular_#{singular}" do
       assert_equal(plural, ActiveSupport::Inflector.pluralize(singular))
       assert_equal(plural.capitalize, ActiveSupport::Inflector.pluralize(singular.capitalize))
     end
   end
 
   SingularToPlural.each do |singular, plural|
-    define_method "test_singularize_#{plural}" do
+    define_method "test_singularize_plural_#{plural}" do
       assert_equal(singular, ActiveSupport::Inflector.singularize(plural))
       assert_equal(singular.capitalize, ActiveSupport::Inflector.singularize(plural.capitalize))
     end
   end
-  
+
   SingularToPlural.each do |singular, plural|
-    define_method "test_pluralize_#{plural}" do
+    define_method "test_pluralize_plural_#{plural}" do
       assert_equal(plural, ActiveSupport::Inflector.pluralize(plural))
       assert_equal(plural.capitalize, ActiveSupport::Inflector.pluralize(plural.capitalize))
     end
diff --git a/activesupport/test/test_case_test.rb b/activesupport/test/test_case_test.rb
index 7e65c63062..756d21b3e4 100644
--- a/activesupport/test/test_case_test.rb
+++ b/activesupport/test/test_case_test.rb
@@ -12,6 +12,10 @@ module ActiveSupport
       def puke(klass, name, e)
         @puked << [klass, name, e]
       end
+
+      def options
+        nil
+      end
     end
 
     if defined?(MiniTest::Assertions) && TestCase < MiniTest::Assertions
diff --git a/ci/ci_build.rb b/ci/ci_build.rb
index 964e2d4eb8..c3af1f0177 100755
--- a/ci/ci_build.rb
+++ b/ci/ci_build.rb
@@ -82,32 +82,72 @@ end
 rm_f "#{root_dir}/activerecord/debug.log"
 cd "#{root_dir}/activerecord" do
   puts
-  puts "[CruiseControl] Building Active Record with MySQL"
+  puts "[CruiseControl] Building Active Record with MySQL IM enabled"
   puts
+  ENV['IM'] = 'true'
   build_results[:activerecord_mysql] = rake 'mysql:rebuild_databases', 'mysql:test'
   build_results[:activerecord_mysql_isolated] = rake 'mysql:rebuild_databases', 'mysql:isolated_test'
 end
 
 cd "#{root_dir}/activerecord" do
   puts
-  puts "[CruiseControl] Building Active Record with MySQL2"
+  puts "[CruiseControl] Building Active Record with MySQL IM disabled"
   puts
+  ENV['IM'] = 'false'
+  build_results[:activerecord_mysql] = rake 'mysql:rebuild_databases', 'mysql:test'
+  build_results[:activerecord_mysql_isolated] = rake 'mysql:rebuild_databases', 'mysql:isolated_test'
+end
+
+cd "#{root_dir}/activerecord" do
+  puts
+  puts "[CruiseControl] Building Active Record with MySQL2 IM enabled"
+  puts
+  ENV['IM'] = 'true'
+  build_results[:activerecord_mysql2] = rake 'mysql:rebuild_databases', 'mysql2:test'
+  build_results[:activerecord_mysql2_isolated] = rake 'mysql:rebuild_databases', 'mysql2:isolated_test'
+end
+
+cd "#{root_dir}/activerecord" do
+  puts
+  puts "[CruiseControl] Building Active Record with MySQL2 IM disabled"
+  puts
+  ENV['IM'] = 'false'
   build_results[:activerecord_mysql2] = rake 'mysql:rebuild_databases', 'mysql2:test'
   build_results[:activerecord_mysql2_isolated] = rake 'mysql:rebuild_databases', 'mysql2:isolated_test'
 end
 
 cd "#{root_dir}/activerecord" do
   puts
-  puts "[CruiseControl] Building Active Record with PostgreSQL"
+  puts "[CruiseControl] Building Active Record with PostgreSQL IM enabled"
   puts
+  ENV['IM'] = 'true'
   build_results[:activerecord_postgresql8] = rake 'postgresql:rebuild_databases', 'postgresql:test'
   build_results[:activerecord_postgresql8_isolated] = rake 'postgresql:rebuild_databases', 'postgresql:isolated_test'
 end
 
 cd "#{root_dir}/activerecord" do
   puts
-  puts "[CruiseControl] Building Active Record with SQLite 3"
+  puts "[CruiseControl] Building Active Record with PostgreSQL IM disabled"
+  puts
+  ENV['IM'] = 'false'
+  build_results[:activerecord_postgresql8] = rake 'postgresql:rebuild_databases', 'postgresql:test'
+  build_results[:activerecord_postgresql8_isolated] = rake 'postgresql:rebuild_databases', 'postgresql:isolated_test'
+end
+
+cd "#{root_dir}/activerecord" do
+  puts
+  puts "[CruiseControl] Building Active Record with SQLite 3 IM enabled"
+  puts
+  ENV['IM'] = 'true'
+  build_results[:activerecord_sqlite3] = rake 'sqlite3:test'
+  build_results[:activerecord_sqlite3_isolated] = rake 'sqlite3:isolated_test'
+end
+
+cd "#{root_dir}/activerecord" do
+  puts
+  puts "[CruiseControl] Building Active Record with SQLite 3 IM disabled"
   puts
+  ENV['IM'] = 'false'
   build_results[:activerecord_sqlite3] = rake 'sqlite3:test'
   build_results[:activerecord_sqlite3_isolated] = rake 'sqlite3:isolated_test'
 end
diff --git a/railties/guides/source/active_support_core_extensions.textile b/railties/guides/source/active_support_core_extensions.textile
index 7becefee09..1df36137b4 100644
--- a/railties/guides/source/active_support_core_extensions.textile
+++ b/railties/guides/source/active_support_core_extensions.textile
@@ -2793,6 +2793,8 @@ h5. +Date.current+
 
 Active Support defines +Date.current+ to be today in the current time zone. That's like +Date.today+, except that it honors the user time zone, if defined. It also defines +Date.yesterday+ and +Date.tomorrow+, and the instance predicates +past?+, +today?+, and +future?+, all of them relative to +Date.current+.
 
+When making Date comparisons using methods which honor the user time zone, make sure to use +Date.current+ and not +Date.today+. There are cases where the user time zone might be in the future compared to the system time zone, which +Date.today+ uses by default. This means +Date.today+ may equal +Date.yesterday+.
+
 h5. Named dates
 
 h6. +prev_year+, +next_year+
@@ -3107,7 +3109,7 @@ h5. Named Datetimes
 
 h6. +DateTime.current+
 
-Active Support defines +DateTime.current+ to be like +Time.now.to_datetime+, except that it honors the user time zone, if defined. It also defines instance predicates +past?+, and +future?+ relative to +DateTime.current+.
+Active Support defines +DateTime.current+ to be like +Time.now.to_datetime+, except that it honors the user time zone, if defined. It also defines +DateTime.yesterday+ and +DateTime.tomorrow+, and the instance predicates +past?+, and +future?+ relative to +DateTime.current+.
 
 h5. Other Extensions
 
@@ -3284,6 +3286,12 @@ t.advance(:seconds => 1)
 
 * If +since+ or +ago+ jump to a time that can't be expressed with +Time+ a +DateTime+ object is returned instead.
 
+h5. +Time.current+
+
+Active Support defines +Time.current+ to be today in the current time zone. That's like +Time.now+, except that it honors the user time zone, if defined. It also defines +Time.yesterday+ and +Time.tomorrow+, and the instance predicates +past?+, +today?+, and +future?+, all of them relative to +Time.current+.
+
+When making Time comparisons using methods which honor the user time zone, make sure to use +Time.current+ and not +Time.now+. There are cases where the user time zone might be in the future compared to the system time zone, which +Time.today+ uses by default. This means +Time.now+ may equal +Time.yesterday+.
+
 h4. Time Constructors
 
 Active Support defines +Time.current+ to be +Time.zone.now+ if there's a user time zone defined, with fallback to +Time.now+:
diff --git a/railties/guides/source/contributing_to_ruby_on_rails.textile b/railties/guides/source/contributing_to_ruby_on_rails.textile
index 9739da2666..82e7edfc84 100644
--- a/railties/guides/source/contributing_to_ruby_on_rails.textile
+++ b/railties/guides/source/contributing_to_ruby_on_rails.textile
@@ -349,7 +349,20 @@ $ git commit -a
 $ git format-patch master --stdout > my_new_patch.diff
 </shell>
 
-Sanity check the results of this operation: open the diff file in your text editor of choice and make sure that no unintended changes crept in.
+Open the diff file in your text editor of choice to sanity check the results, and make sure that no unintended changes crept in.
+
+You can also perform an extra check by applying the patch to a different dedicated branch:
+
+<shell>
+$ git checkout -b testing_branch
+$ git apply --check my_new_patch.diff
+</shell>
+
+Please make sure the patch does not introduce whitespace errors:
+
+<shell>
+$ git apply --whitespace=error-all mynew_patch.diff
+</shell>
 
 You can check your patches by applying your patch to an different dedicated branch:
 
diff --git a/railties/lib/rails/commands/server.rb b/railties/lib/rails/commands/server.rb
index c3927b6613..e447209242 100644
--- a/railties/lib/rails/commands/server.rb
+++ b/railties/lib/rails/commands/server.rb
@@ -42,6 +42,10 @@ module Rails
       set_environment
     end
 
+    def app
+      @app ||= super.instance
+    end
+
     def opt_parser
       Options.new
     end
diff --git a/railties/lib/rails/engine.rb b/railties/lib/rails/engine.rb
index 4ce874d4b9..50bba22a3a 100644
--- a/railties/lib/rails/engine.rb
+++ b/railties/lib/rails/engine.rb
@@ -382,7 +382,10 @@ module Rails
 
       # Finds engine with given path
       def find(path)
-        Rails::Engine::Railties.engines.find { |r| File.expand_path(r.root.to_s) == File.expand_path(path.to_s) }
+        path = path.to_s
+        Rails::Engine::Railties.engines.find { |r|
+          File.expand_path(r.root.to_s) == File.expand_path(path)
+        }
       end
     end
 
diff --git a/railties/lib/rails/generators/actions.rb b/railties/lib/rails/generators/actions.rb
index d7a86a5c40..c323df3e95 100644
--- a/railties/lib/rails/generators/actions.rb
+++ b/railties/lib/rails/generators/actions.rb
@@ -264,17 +264,18 @@ module Rails
       #   readme "README"
       #
       def readme(path)
-        say File.read(find_in_source_paths(path))
+        log File.read(find_in_source_paths(path))
       end
 
       protected
 
         # Define log for backwards compatibility. If just one argument is sent,
-        # invoke say, otherwise invoke say_status.
+        # invoke say, otherwise invoke say_status. Differently from say and
+        # similarly to say_status, this method respects the quiet? option given.
         #
         def log(*args)
           if args.size == 1
-            say args.first.to_s
+            say args.first.to_s unless options.quiet?
           else
             args << (self.behavior == :invoke ? :green : :red)
             say_status *args
diff --git a/railties/lib/rails/generators/base.rb b/railties/lib/rails/generators/base.rb
index 131eb6ff6f..dfecd2a6e4 100644
--- a/railties/lib/rails/generators/base.rb
+++ b/railties/lib/rails/generators/base.rb
@@ -3,7 +3,7 @@ begin
 rescue LoadError
   puts "Thor is not available.\nIf you ran this command from a git checkout " \
        "of Rails, please make sure thor is installed,\nand run this command " \
-       "as `ruby #{$0} #{ARGV.join(" ")} --dev`"
+       "as `ruby #{$0} #{(ARGV | ['--dev']).join(" ")}`"
   exit
 end
 
diff --git a/railties/lib/rails/generators/rails/app/templates/public/index.html b/railties/lib/rails/generators/rails/app/templates/public/index.html
index 75d5edd06d..13a203dd08 100644
--- a/railties/lib/rails/generators/rails/app/templates/public/index.html
+++ b/railties/lib/rails/generators/rails/app/templates/public/index.html
@@ -52,7 +52,6 @@
         clear: both;
       }
 
-
       #header, #about, #getting-started {
         padding-left: 75px;
         padding-right: 30px;
@@ -168,6 +167,9 @@
         margin-bottom: 5px;
       }
 
+      .filename {
+        font-style: italic;
+      }
     </style>
     <script type="text/javascript">
       function about() {
@@ -190,10 +192,10 @@
           <li>
             <h3>Browse the documentation</h3>
             <ul class="links">
-              <li><a href="http://api.rubyonrails.org/">Rails API</a></li>
-              <li><a href="http://stdlib.rubyonrails.org/">Ruby standard library</a></li>
-              <li><a href="http://corelib.rubyonrails.org/">Ruby core</a></li>
               <li><a href="http://guides.rubyonrails.org/">Rails Guides</a></li>
+              <li><a href="http://api.rubyonrails.org/">Rails API</a></li>
+              <li><a href="http://www.ruby-doc.org/core/">Ruby core</a></li>
+              <li><a href="http://www.ruby-doc.org/stdlib/">Ruby standard library</a></li>
             </ul>
           </li>
         </ul>
@@ -221,13 +223,13 @@
             </li>
 
             <li>
-              <h2>Set up a default route and remove or rename this file</h2>
-              <p>Routes are set up in config/routes.rb.</p>
+              <h2>Set up a default route and remove <span class="filename">public/index.html</span></h2>
+              <p>Routes are set up in <span class="filename">config/routes.rb</span>.</p>
             </li>
 
             <li>
               <h2>Create your database</h2>
-              <p>Run <code>rake db:migrate</code> to create your database. If you're not using SQLite (the default), edit <code>config/database.yml</code> with your username and password.</p>
+              <p>Run <code>rake db:create</code> to create your database. If you're not using SQLite (the default), edit <span class="filename">config/database.yml</span> with your username and password.</p>
             </li>
           </ol>
         </div>
diff --git a/railties/test/generators/actions_test.rb b/railties/test/generators/actions_test.rb
index 4b29afdc8f..68d4c17623 100644
--- a/railties/test/generators/actions_test.rb
+++ b/railties/test/generators/actions_test.rb
@@ -191,6 +191,31 @@ class ActionsTest < Rails::Generators::TestCase
     assert_match(/Welcome to Rails/, action(:readme, "README"))
   end
 
+  def test_readme_with_quiet
+    generator(default_arguments, :quiet => true)
+    run_generator
+    Rails::Generators::AppGenerator.expects(:source_root).times(2).returns(destination_root)
+    assert_no_match(/Welcome to Rails/, action(:readme, "README"))
+  end
+
+  def test_log
+    assert_equal("YES\n", action(:log, "YES"))
+  end
+
+  def test_log_with_status
+    assert_equal("         yes  YES\n", action(:log, :yes, "YES"))
+  end
+
+  def test_log_with_quiet
+    generator(default_arguments, :quiet => true)
+    assert_equal("", action(:log, "YES"))
+  end
+
+  def test_log_with_status_with_quiet
+    generator(default_arguments, :quiet => true)
+    assert_equal("", action(:log, :yes, "YES"))
+  end
+
   protected
 
     def action(*args, &block)