Merge branch 'master' of github.com:lifo/docrails

115 files changed, 2115 insertions, 656 deletions

diff --git a/Gemfile b/Gemfile
index 7d8949409c..879598c6db 100644
--- a/Gemfile
+++ b/Gemfile
@@ -36,6 +36,9 @@ platforms :mri_19 do
 end
 
 platforms :ruby do
+  if ENV["RB_FSEVENT"]
+    gem 'rb-fsevent'
+  end
   gem 'json'
   gem 'yajl-ruby'
   gem "nokogiri", ">= 1.4.4"
diff --git a/actionpack/lib/abstract_controller/callbacks.rb b/actionpack/lib/abstract_controller/callbacks.rb
index 95992c2698..1943ca4436 100644
--- a/actionpack/lib/abstract_controller/callbacks.rb
+++ b/actionpack/lib/abstract_controller/callbacks.rb
@@ -14,7 +14,7 @@ module AbstractController
     # Override AbstractController::Base's process_action to run the
     # process_action callbacks around the normal behavior.
     def process_action(method_name, *args)
-      run_callbacks(:process_action, method_name) do
+      run_callbacks(:process_action, action_name) do
         super
       end
     end
diff --git a/actionpack/lib/action_controller/caching/actions.rb b/actionpack/lib/action_controller/caching/actions.rb
index 2c8a6e4d4d..5fc6956266 100644
--- a/actionpack/lib/action_controller/caching/actions.rb
+++ b/actionpack/lib/action_controller/caching/actions.rb
@@ -56,19 +56,18 @@ module ActionController #:nodoc:
     #
     #     caches_page :public
     #
-    #     caches_action :index, :if => proc do |c|
-    #       !c.request.format.json?  # cache if is not a JSON request
+    #     caches_action :index, :if => proc do
+    #       !request.format.json?  # cache if is not a JSON request
     #     end
     #
     #     caches_action :show, :cache_path => { :project => 1 },
     #       :expires_in => 1.hour
     #
-    #     caches_action :feed, :cache_path => proc do |c|
-    #       if c.params[:user_id]
-    #         c.send(:user_list_url,
-    #           c.params[:user_id], c.params[:id])
+    #     caches_action :feed, :cache_path => proc do
+    #       if params[:user_id]
+    #         user_list_url(params[:user_id, params[:id])
     #       else
-    #         c.send(:list_url, c.params[:id])
+    #         list_url(params[:id])
     #       end
     #     end
     #   end
diff --git a/actionpack/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb b/actionpack/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb
index 50d8ca9484..2099fd069a 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb
@@ -1,7 +1,7 @@
 <h1>
   <%=h @exception.class.to_s %>
   <% if @request.parameters['controller'] %>
-    in <%=h @request.parameters['controller'].humanize %>Controller<% if @request.parameters['action'] %>#<%=h @request.parameters['action'] %><% end %>
+    in <%=h @request.parameters['controller'].classify.pluralize %>Controller<% if @request.parameters['action'] %>#<%=h @request.parameters['action'] %><% end %>
   <% end %>
 </h1>
 <pre><%=h @exception.message %></pre>
diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index 64368ca28f..14c424f24b 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -107,7 +107,7 @@ module ActionDispatch
             if @options[:format] == false
               @options.delete(:format)
               path
-            elsif path.include?(":format") || path.end_with?('/')
+            elsif path.include?(":format") || path.end_with?('/') || path.match(/^\/?\*/)
               path
             else
               "#{path}(.:format)"
@@ -195,8 +195,8 @@ module ActionDispatch
 
           def request_method_condition
             if via = @options[:via]
-              via = Array(via).map { |m| m.to_s.dasherize.upcase }
-              { :request_method => %r[^#{via.join('|')}$] }
+              list = Array(via).map { |m| m.to_s.dasherize.upcase }
+              { :request_method => list }
             else
               { }
             end
@@ -372,8 +372,9 @@ module ActionDispatch
         #     # Matches any request starting with 'path'
         #     match 'path' => 'c#a', :anchor => false
         def match(path, options=nil)
-          mapping = Mapping.new(@set, @scope, path, options || {}).to_route
-          @set.add_route(*mapping)
+          mapping = Mapping.new(@set, @scope, path, options || {})
+          app, conditions, requirements, defaults, as, anchor = mapping.to_route
+          @set.add_route(app, conditions, requirements, defaults, as, anchor)
           self
         end
 
diff --git a/actionpack/lib/action_dispatch/routing/route.rb b/actionpack/lib/action_dispatch/routing/route.rb
index eae9d4ea6d..a049510182 100644
--- a/actionpack/lib/action_dispatch/routing/route.rb
+++ b/actionpack/lib/action_dispatch/routing/route.rb
@@ -12,6 +12,8 @@ module ActionDispatch
         @defaults = defaults
         @name = name
 
+        # FIXME: we should not be doing this much work in a constructor.
+
         @requirements = requirements.merge(defaults)
         @requirements.delete(:controller) if @requirements[:controller].is_a?(Regexp)
         @requirements.delete_if { |k, v|
@@ -23,21 +25,22 @@ module ActionDispatch
           conditions[:path_info] = ::Rack::Mount::Strexp.compile(path, requirements, SEPARATORS, anchor)
         end
 
-        @conditions = Hash[conditions.map { |k,v| [k, Rack::Mount::RegexpWithNamedGroups.new(v)] }]
+        @verbs = conditions[:request_method] || []
+
+        @conditions = conditions.dup
+
+        # Rack-Mount requires that :request_method be a regular expression.
+        # :request_method represents the HTTP verb that matches this route.
+        #
+        # Here we munge values before they get sent on to rack-mount.
+        @conditions[:request_method] = %r[^#{verb}$] unless @verbs.empty?
+        @conditions[:path_info] = Rack::Mount::RegexpWithNamedGroups.new(@conditions[:path_info]) if @conditions[:path_info]
         @conditions.delete_if{ |k,v| k != :path_info && !valid_condition?(k) }
         @requirements.delete_if{ |k,v| !valid_condition?(k) }
       end
 
       def verb
-        if method = conditions[:request_method]
-          case method
-          when Regexp
-            source = method.source.upcase
-            source =~ /\A\^[-A-Z|]+\$\Z/ ? source[1..-2] : source
-          else
-            method.to_s.upcase
-          end
-        end
+        @verbs.join '|'
       end
 
       def segment_keys
diff --git a/actionpack/lib/action_view/helpers/number_helper.rb b/actionpack/lib/action_view/helpers/number_helper.rb
index 4e44843c4b..05a9c5b4f1 100644
--- a/actionpack/lib/action_view/helpers/number_helper.rb
+++ b/actionpack/lib/action_view/helpers/number_helper.rb
@@ -472,7 +472,7 @@ module ActionView
         end.keys.map{|e_name| inverted_du[e_name] }.sort_by{|e| -e}
 
         number_exponent = number != 0 ? Math.log10(number.abs).floor : 0
-        display_exponent = unit_exponents.find{|e| number_exponent >= e }
+        display_exponent = unit_exponents.find{ |e| number_exponent >= e } || 0
         number  /= 10 ** display_exponent
 
         unit = case units
diff --git a/actionpack/lib/action_view/template/resolver.rb b/actionpack/lib/action_view/template/resolver.rb
index 589b2a1a76..6c1063592f 100644
--- a/actionpack/lib/action_view/template/resolver.rb
+++ b/actionpack/lib/action_view/template/resolver.rb
@@ -5,6 +5,25 @@ require "action_view/template"
 module ActionView
   # = Action View Resolver
   class Resolver
+    # Keeps all information about view path and builds virtual path.
+    class Path < String
+      attr_reader :name, :prefix, :partial, :virtual
+      alias_method :partial?, :partial
+
+      def initialize(name, prefix, partial)
+        @name, @prefix, @partial = name, prefix, partial
+        rebuild(@name, @prefix, @partial)
+      end
+
+      def rebuild(name, prefix, partial)
+        @virtual = ""
+        @virtual << "#{prefix}/" unless prefix.empty?
+        @virtual << (partial ? "_#{name}" : name)
+
+        self.replace(@virtual)
+      end
+    end
+
     cattr_accessor :caching
     self.caching = true
 
@@ -41,10 +60,7 @@ module ActionView
 
     # Helpers that builds a path. Useful for building virtual paths.
     def build_path(name, prefix, partial)
-      path = ""
-      path << "#{prefix}/" unless prefix.empty?
-      path << (partial ? "_#{name}" : name)
-      path
+      Path.new(name, prefix, partial)
     end
 
     # Handles templates caching. If a key is given and caching is on
@@ -97,25 +113,24 @@ module ActionView
   end
 
   class PathResolver < Resolver
-    EXTENSION_ORDER = [:locale, :formats, :handlers]
+    EXTENSIONS = [:locale, :formats, :handlers]
+    DEFAULT_PATTERN = ":prefix/:action{.:locale,}{.:formats,}{.:handlers,}"
+
+    def initialize(pattern=nil)
+      @pattern = pattern || DEFAULT_PATTERN
+      super()
+    end
 
     private
 
     def find_templates(name, prefix, partial, details)
       path = build_path(name, prefix, partial)
-      query(path, EXTENSION_ORDER.map { |ext| details[ext] }, details[:formats])
+      extensions = Hash[EXTENSIONS.map { |ext| [ext, details[ext]] }.flatten(0)]
+      query(path, extensions, details[:formats])
     end
 
     def query(path, exts, formats)
-      query = File.join(@path, path)
-
-      query << exts.map { |ext|
-        "{#{ext.compact.map { |e| ".#{e}" }.join(',')},}"
-      }.join
-
-      query.gsub!(/\{\.html,/, "{.html,.text.html,")
-      query.gsub!(/\{\.text,/, "{.text,.text.plain,")
-
+      query = build_query(path, exts)
       templates = []
       sanitizer = Hash.new { |h,k| h[k] = Dir["#{File.dirname(k)}/*"] }
 
@@ -126,12 +141,28 @@ module ActionView
         contents = File.open(p, "rb") {|io| io.read }
 
         templates << Template.new(contents, File.expand_path(p), handler,
-          :virtual_path => path, :format => format, :updated_at => mtime(p))
+          :virtual_path => path.virtual, :format => format, :updated_at => mtime(p))
       end
 
       templates
     end
 
+    # Helper for building query glob string based on resolver's pattern. 
+    def build_query(path, exts)
+      query = @pattern.dup
+      query.gsub!(/\:prefix(\/)?/, path.prefix.empty? ? "" : "#{path.prefix}\\1") # prefix can be empty...
+      query.gsub!(/\:action/, path.partial? ? "_#{path.name}" : path.name)
+
+      exts.each { |ext, variants|
+        query.gsub!(/\:#{ext}/, "{#{variants.compact.uniq.join(',')}}")
+      }
+
+      query.gsub!(/\.{html,/, ".{html,text.html,")
+      query.gsub!(/\.{text,/, ".{text,text.plain,")
+
+      File.expand_path(query, @path)
+    end
+
     # Returns the file mtime from the filesystem.
     def mtime(p)
       File.stat(p).mtime
@@ -149,11 +180,47 @@ module ActionView
     end
   end
 
-  # A resolver that loads files from the filesystem.
+  # A resolver that loads files from the filesystem. It allows to set your own
+  # resolving pattern. Such pattern can be a glob string supported by some variables.
+  #
+  # ==== Examples
+  #
+  # Default pattern, loads views the same way as previous versions of rails, eg. when you're
+  # looking for `users/new` it will produce query glob: `users/new{.{en},}{.{html,js},}{.{erb,haml,rjs},}`
+  #
+  #   FileSystemResolver.new("/path/to/views", ":prefix/:action{.:locale,}{.:formats,}{.:handlers,}")
+  #
+  # This one allows you to keep files with different formats in seperated subdirectories,
+  # eg. `users/new.html` will be loaded from `users/html/new.erb` or `users/new.html.erb`,
+  # `users/new.js` from `users/js/new.erb` or `users/new.js.erb`, etc.
+  #
+  #   FileSystemResolver.new("/path/to/views", ":prefix/{:formats/,}:action{.:locale,}{.:formats,}{.:handlers,}")
+  #
+  # If you don't specify pattern then the default will be used.
+  #
+  # In order to use any of the customized resolvers above in a Rails application, you just need
+  # to configure ActionController::Base.view_paths in an initializer, for example:
+  #
+  #   ActionController::Base.view_paths = FileSystemResolver.new(
+  #     Rails.root.join("app/views"),
+  #     ":prefix{/:locale}/:action{.:formats,}{.:handlers,}"
+  #   )
+  #
+  # ==== Pattern format and variables
+  #
+  # Pattern have to be a valid glob string, and it allows you to use the
+  # following variables:
+  #
+  # * <tt>:prefix</tt> - usualy the controller path
+  # * <tt>:action</tt> - name of the action
+  # * <tt>:locale</tt> - possible locale versions
+  # * <tt>:formats</tt> - possible request formats (for example html, json, xml...)
+  # * <tt>:handlers</tt> - possible handlers (for example erb, haml, builder...)
+  #
   class FileSystemResolver < PathResolver
-    def initialize(path)
+    def initialize(path, pattern=nil)
       raise ArgumentError, "path already is a Resolver class" if path.is_a?(Resolver)
-      super()
+      super(pattern)
       @path = File.expand_path(path)
     end
 
diff --git a/actionpack/lib/action_view/testing/resolvers.rb b/actionpack/lib/action_view/testing/resolvers.rb
index 5c5cab7c7d..773dfcbb1d 100644
--- a/actionpack/lib/action_view/testing/resolvers.rb
+++ b/actionpack/lib/action_view/testing/resolvers.rb
@@ -8,8 +8,8 @@ module ActionView #:nodoc:
   class FixtureResolver < PathResolver
     attr_reader :hash
 
-    def initialize(hash = {})
-      super()
+    def initialize(hash = {}, pattern=nil)
+      super(pattern)
       @hash = hash
     end
 
@@ -21,8 +21,8 @@ module ActionView #:nodoc:
 
     def query(path, exts, formats)
       query = ""
-      exts.each do |ext|
-        query << '(' << ext.map {|e| e && Regexp.escape(".#{e}") }.join('|') << '|)'
+      EXTENSIONS.each do |ext|
+        query << '(' << exts[ext].map {|e| e && Regexp.escape(".#{e}") }.join('|') << '|)'
       end
       query = /^(#{Regexp.escape(path)})#{query}$/
 
@@ -32,9 +32,9 @@ module ActionView #:nodoc:
         next unless _path =~ query
         handler, format = extract_handler_and_format(_path, formats)
         templates << Template.new(source, _path, handler,
-          :virtual_path => $1, :format => format, :updated_at => updated_at)
+          :virtual_path => path.virtual, :format => format, :updated_at => updated_at)
       end
-
+      
       templates.sort_by {|t| -t.identifier.match(/^#{query}$/).captures.reject(&:blank?).size }
     end
   end
diff --git a/actionpack/test/action_dispatch/routing/mapper_test.rb b/actionpack/test/action_dispatch/routing/mapper_test.rb
index 9966234f1b..e21b271907 100644
--- a/actionpack/test/action_dispatch/routing/mapper_test.rb
+++ b/actionpack/test/action_dispatch/routing/mapper_test.rb
@@ -46,6 +46,13 @@ module ActionDispatch
         mapper.match '/one/two/', :to => 'posts#index', :as => :main
         assert_equal '/one/two(.:format)', fakeset.conditions.first[:path_info]
       end
+
+      def test_map_wildcard
+        fakeset = FakeSet.new
+        mapper = Mapper.new fakeset
+        mapper.match '/*path', :to => 'pages#show', :as => :page
+        assert_equal '/*path', fakeset.conditions.first[:path_info]
+      end
     end
   end
 end
diff --git a/actionpack/test/controller/filters_test.rb b/actionpack/test/controller/filters_test.rb
index 330fa276d0..9e44e8e088 100644
--- a/actionpack/test/controller/filters_test.rb
+++ b/actionpack/test/controller/filters_test.rb
@@ -505,6 +505,21 @@ class FilterTest < ActionController::TestCase
     end
   end
 
+  class ImplicitActionsController < ActionController::Base
+    before_filter :find_only, :only => :edit
+    before_filter :find_except, :except => :edit
+
+    private
+
+    def find_only
+      @only = 'Only'
+    end
+
+    def find_except
+      @except = 'Except'
+    end
+  end
+
   def test_sweeper_should_not_block_rendering
     response = test_process(SweeperTestController)
     assert_equal 'hello world', response.body
@@ -783,6 +798,18 @@ class FilterTest < ActionController::TestCase
     assert_equal("I rescued this: #<FilterTest::ErrorToRescue: Something made the bad noise.>", response.body)
   end
 
+  def test_filters_obey_only_and_except_for_implicit_actions
+    test_process(ImplicitActionsController, 'show')
+    assert_equal 'Except', assigns(:except)
+    assert_nil assigns(:only)
+    assert_equal 'show', response.body
+
+    test_process(ImplicitActionsController, 'edit')
+    assert_equal 'Only', assigns(:only)
+    assert_nil assigns(:except)
+    assert_equal 'edit', response.body
+  end
+
   private
     def test_process(controller, action = "show")
       @controller = controller.is_a?(Class) ? controller.new : controller
diff --git a/actionpack/test/dispatch/show_exceptions_test.rb b/actionpack/test/dispatch/show_exceptions_test.rb
index 2a478c214f..e453dd11ce 100644
--- a/actionpack/test/dispatch/show_exceptions_test.rb
+++ b/actionpack/test/dispatch/show_exceptions_test.rb
@@ -7,6 +7,8 @@ class ShowExceptionsTest < ActionDispatch::IntegrationTest
     case req.path
     when "/not_found"
       raise ActionController::UnknownAction
+    when "/runtime_error"
+      raise RuntimeError
     when "/method_not_allowed"
       raise ActionController::MethodNotAllowed
     when "/not_implemented"
@@ -121,4 +123,18 @@ class ShowExceptionsTest < ActionDispatch::IntegrationTest
     assert_response 404
     assert_match(/AbstractController::ActionNotFound/, body)
   end
+
+  test "show the controller name in the diagnostics template when controller name is present" do
+    @app = ProductionApp
+    get("/runtime_error", {}, {
+      'action_dispatch.show_exceptions' => true,
+      'action_dispatch.request.parameters' => {
+        'action' => 'show',
+        'id' => 'unknown',
+        'controller' => 'featured_tiles'
+      }
+    })
+    assert_response 500
+    assert_match(/RuntimeError\n    in FeaturedTilesController/, body)
+  end
 end
diff --git a/actionpack/test/fixtures/custom_pattern/another.html.erb b/actionpack/test/fixtures/custom_pattern/another.html.erb
new file mode 100644
index 0000000000..6d7f3bafbb
--- /dev/null
+++ b/actionpack/test/fixtures/custom_pattern/another.html.erb
@@ -0,0 +1 @@
+Hello custom patterns!
\ No newline at end of file
diff --git a/actionpack/test/fixtures/custom_pattern/html/another.erb b/actionpack/test/fixtures/custom_pattern/html/another.erb
new file mode 100644
index 0000000000..dbd7e96ab6
--- /dev/null
+++ b/actionpack/test/fixtures/custom_pattern/html/another.erb
@@ -0,0 +1 @@
+Another template!
\ No newline at end of file
diff --git a/actionpack/test/fixtures/custom_pattern/html/path.erb b/actionpack/test/fixtures/custom_pattern/html/path.erb
new file mode 100644
index 0000000000..6d7f3bafbb
--- /dev/null
+++ b/actionpack/test/fixtures/custom_pattern/html/path.erb
@@ -0,0 +1 @@
+Hello custom patterns!
\ No newline at end of file
diff --git a/actionpack/test/fixtures/filter_test/implicit_actions/edit.html.erb b/actionpack/test/fixtures/filter_test/implicit_actions/edit.html.erb
new file mode 100644
index 0000000000..8491ab9f80
--- /dev/null
+++ b/actionpack/test/fixtures/filter_test/implicit_actions/edit.html.erb
@@ -0,0 +1 @@
+edit
\ No newline at end of file
diff --git a/actionpack/test/fixtures/filter_test/implicit_actions/show.html.erb b/actionpack/test/fixtures/filter_test/implicit_actions/show.html.erb
new file mode 100644
index 0000000000..0a89cecf05
--- /dev/null
+++ b/actionpack/test/fixtures/filter_test/implicit_actions/show.html.erb
@@ -0,0 +1 @@
+show
\ No newline at end of file
diff --git a/actionpack/test/template/number_helper_test.rb b/actionpack/test/template/number_helper_test.rb
index c1b4bab903..c8d50ebf75 100644
--- a/actionpack/test/template/number_helper_test.rb
+++ b/actionpack/test/template/number_helper_test.rb
@@ -195,7 +195,9 @@ class NumberHelperTest < ActionView::TestCase
 
   def test_number_to_human
     assert_equal '-123', number_to_human(-123)
-    assert_equal '0', number_to_human(0)
+    assert_equal '-0.5', number_to_human(-0.5)
+    assert_equal '0',   number_to_human(0)
+    assert_equal '0.5', number_to_human(0.5)
     assert_equal '123', number_to_human(123)
     assert_equal '1.23 Thousand', number_to_human(1234)
     assert_equal '12.3 Thousand', number_to_human(12345)
diff --git a/actionpack/test/template/render_test.rb b/actionpack/test/template/render_test.rb
index 034fb6c210..dd86bfed04 100644
--- a/actionpack/test/template/render_test.rb
+++ b/actionpack/test/template/render_test.rb
@@ -381,7 +381,7 @@ class LazyViewRenderTest < ActiveSupport::TestCase
     end
 
     def test_render_utf8_template_with_incompatible_external_encoding
-      with_external_encoding Encoding::SJIS do
+      with_external_encoding Encoding::SHIFT_JIS do
         begin
           result = @view.render(:file => "test/utf8.html.erb", :layouts => "layouts/yield")
           flunk 'Should have raised incompatible encoding error'
@@ -392,7 +392,7 @@ class LazyViewRenderTest < ActiveSupport::TestCase
     end
 
     def test_render_utf8_template_with_partial_with_incompatible_encoding
-      with_external_encoding Encoding::SJIS do
+      with_external_encoding Encoding::SHIFT_JIS do
         begin
           result = @view.render(:file => "test/utf8_magic_with_bare_partial.html.erb", :layouts => "layouts/yield")
           flunk 'Should have raised incompatible encoding error'
diff --git a/actionpack/test/template/resolver_patterns_test.rb b/actionpack/test/template/resolver_patterns_test.rb
new file mode 100644
index 0000000000..97b1bad055
--- /dev/null
+++ b/actionpack/test/template/resolver_patterns_test.rb
@@ -0,0 +1,31 @@
+require 'abstract_unit'
+
+class ResolverPatternsTest < ActiveSupport::TestCase
+  def setup
+    path = File.expand_path("../../fixtures/", __FILE__)
+    pattern = ":prefix/{:formats/,}:action{.:formats,}{.:handlers,}"
+    @resolver = ActionView::FileSystemResolver.new(path, pattern)
+  end
+
+  def test_should_return_empty_list_for_unknown_path
+    templates = @resolver.find_all("unknown", "custom_pattern", false, {:locale => [], :formats => [:html], :handlers => [:erb]})
+    assert_equal [], templates, "expected an empty list of templates"
+  end
+
+  def test_should_return_template_for_declared_path
+    templates = @resolver.find_all("path", "custom_pattern", false, {:locale => [], :formats => [:html], :handlers => [:erb]})
+    assert_equal 1, templates.size, "expected one template"
+    assert_equal "Hello custom patterns!", templates.first.source
+    assert_equal "custom_pattern/path",    templates.first.virtual_path
+    assert_equal [:html],                  templates.first.formats
+  end
+
+  def test_should_return_all_templates_when_ambigous_pattern
+    templates = @resolver.find_all("another", "custom_pattern", false, {:locale => [], :formats => [:html], :handlers => [:erb]})
+    assert_equal 2, templates.size, "expected two templates"
+    assert_equal "Another template!",      templates[0].source
+    assert_equal "custom_pattern/another", templates[0].virtual_path
+    assert_equal "Hello custom patterns!", templates[1].source
+    assert_equal "custom_pattern/another", templates[1].virtual_path
+  end
+end
diff --git a/activemodel/lib/active_model/attribute_methods.rb b/activemodel/lib/active_model/attribute_methods.rb
index 2a99450a3d..be55581c66 100644
--- a/activemodel/lib/active_model/attribute_methods.rb
+++ b/activemodel/lib/active_model/attribute_methods.rb
@@ -106,11 +106,14 @@ module ActiveModel
         if block_given?
           sing.send :define_method, name, &block
         else
-          # use eval instead of a block to work around a memory leak in dev
-          # mode in fcgi
-          sing.class_eval <<-eorb, __FILE__, __LINE__ + 1
-            def #{name}; #{value.nil? ? 'nil' : value.to_s.inspect}; end
-          eorb
+          if name =~ /^[a-zA-Z_]\w*[!?=]?$/
+            sing.class_eval <<-eorb, __FILE__, __LINE__ + 1
+                def #{name}; #{value.nil? ? 'nil' : value.to_s.inspect}; end
+            eorb
+          else
+            value = value.to_s if value
+            sing.send(:define_method, name) { value }
+          end
         end
       end
 
diff --git a/activemodel/lib/active_model/lint.rb b/activemodel/lib/active_model/lint.rb
index 957d1b9d70..b71ef4b22e 100644
--- a/activemodel/lib/active_model/lint.rb
+++ b/activemodel/lib/active_model/lint.rb
@@ -23,7 +23,7 @@ module ActiveModel
       def test_to_key
         assert model.respond_to?(:to_key), "The model should respond to to_key"
         def model.persisted?() false end
-        assert model.to_key.nil?
+        assert model.to_key.nil?, "to_key should return nil when `persisted?` returns false"
       end
 
       # == Responds to <tt>to_param</tt>
@@ -40,7 +40,7 @@ module ActiveModel
         assert model.respond_to?(:to_param), "The model should respond to to_param"
         def model.to_key() [1] end
         def model.persisted?() false end
-        assert model.to_param.nil?
+        assert model.to_param.nil?, "to_param should return nil when `persisted?` returns false"
       end
 
       # == Responds to <tt>valid?</tt>
diff --git a/activemodel/test/cases/attribute_methods_test.rb b/activemodel/test/cases/attribute_methods_test.rb
index b001adb35a..022c6716bd 100644
--- a/activemodel/test/cases/attribute_methods_test.rb
+++ b/activemodel/test/cases/attribute_methods_test.rb
@@ -5,6 +5,12 @@ class ModelWithAttributes
 
   attribute_method_suffix ''
 
+  class << self
+    define_method(:bar) do
+      'original bar'
+    end
+  end
+
   def attributes
     { :foo => 'value of foo' }
   end
@@ -36,6 +42,27 @@ private
   end
 end
 
+class ModelWithWeirdNamesAttributes
+  include ActiveModel::AttributeMethods
+
+  attribute_method_suffix ''
+
+  class << self
+    define_method(:'c?d') do
+      'original c?d'
+    end
+  end
+
+  def attributes
+    { :'a?b' => 'value of a?b' }
+  end
+
+private
+  def attribute(name)
+    attributes[name.to_sym]
+  end
+end
+
 class AttributeMethodsTest < ActiveModel::TestCase
   test 'unrelated classes should not share attribute method matchers' do
     assert_not_equal ModelWithAttributes.send(:attribute_method_matchers),
@@ -49,6 +76,14 @@ class AttributeMethodsTest < ActiveModel::TestCase
     assert_equal "value of foo", ModelWithAttributes.new.foo
   end
 
+  test '#define_attribute_method generates attribute method with invalid identifier characters' do
+    ModelWithWeirdNamesAttributes.define_attribute_method(:'a?b')
+    ModelWithWeirdNamesAttributes.define_attribute_method(:'a?b')
+
+    assert_respond_to ModelWithWeirdNamesAttributes.new, :'a?b'
+    assert_equal "value of a?b", ModelWithWeirdNamesAttributes.new.send('a?b')
+  end
+
   test '#define_attribute_methods generates attribute methods' do
     ModelWithAttributes.define_attribute_methods([:foo])
 
@@ -58,15 +93,33 @@ class AttributeMethodsTest < ActiveModel::TestCase
 
   test '#define_attribute_methods generates attribute methods with spaces in their names' do
     ModelWithAttributesWithSpaces.define_attribute_methods([:'foo bar'])
-  
+
     assert_respond_to ModelWithAttributesWithSpaces.new, :'foo bar'
     assert_equal "value of foo bar", ModelWithAttributesWithSpaces.new.send(:'foo bar')
   end
-  
+
+  test '#define_attr_method generates attribute method' do
+    ModelWithAttributes.define_attr_method(:bar, 'bar')
+
+    assert_respond_to ModelWithAttributes, :bar
+    assert_equal "original bar", ModelWithAttributes.original_bar
+    assert_equal "bar", ModelWithAttributes.bar
+    ModelWithAttributes.define_attr_method(:bar)
+    assert !ModelWithAttributes.bar
+  end
+
+  test '#define_attr_method generates attribute method with invalid identifier characters' do
+    ModelWithWeirdNamesAttributes.define_attr_method(:'c?d', 'c?d')
+
+    assert_respond_to ModelWithWeirdNamesAttributes, :'c?d'
+    assert_equal "original c?d", ModelWithWeirdNamesAttributes.send('original_c?d')
+    assert_equal "c?d", ModelWithWeirdNamesAttributes.send('c?d')
+  end
+
   test '#alias_attribute works with attributes with spaces in their names' do
     ModelWithAttributesWithSpaces.define_attribute_methods([:'foo bar'])
     ModelWithAttributesWithSpaces.alias_attribute(:'foo_bar', :'foo bar')
-  
+
     assert_equal "value of foo bar", ModelWithAttributesWithSpaces.new.foo_bar
   end
 
diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 8b4e9a34cb..6be46349fb 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,11 @@
 *Rails 3.1.0 (unreleased)*
 
+* Associations with a :through option can now use *any* association as the
+  through or source association, including other associations which have a
+  :through option and has_and_belongs_to_many associations
+
+  [Jon Leighton]
+
 * The configuration for the current database connection is now accessible via
   ActiveRecord::Base.connection_config. [fxn]
 
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index e91cbd7f33..08fb6bf3c4 100644
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -52,14 +52,6 @@ module ActiveRecord
     end
   end
 
-  class HasManyThroughSourceAssociationMacroError < ActiveRecordError #:nodoc:
-    def initialize(reflection)
-      through_reflection = reflection.through_reflection
-      source_reflection  = reflection.source_reflection
-      super("Invalid source reflection macro :#{source_reflection.macro}#{" :through" if source_reflection.options[:through]} for has_many #{reflection.name.inspect}, :through => #{through_reflection.name.inspect}.  Use :source to specify the source reflection.")
-    end
-  end
-
   class HasManyThroughCantAssociateThroughHasOneOrManyReflection < ActiveRecordError #:nodoc:
     def initialize(owner, reflection)
       super("Cannot modify association '#{owner.class.name}##{reflection.name}' because the source reflection class '#{reflection.source_reflection.class_name}' is associated to '#{reflection.through_reflection.class_name}' via :#{reflection.source_reflection.macro}.")
@@ -78,6 +70,12 @@ module ActiveRecord
     end
   end
 
+  class HasManyThroughNestedAssociationsAreReadonly < ActiveRecordError #:nodoc
+    def initialize(owner, reflection)
+      super("Cannot modify association '#{owner.class.name}##{reflection.name}' because it goes through more than one other association.")
+    end
+  end
+
   class HasAndBelongsToManyAssociationWithPrimaryKeyError < ActiveRecordError #:nodoc:
     def initialize(reflection)
       super("Primary key is not allowed in a has_and_belongs_to_many join table (#{reflection.options[:join_table]}).")
@@ -142,8 +140,11 @@ 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'
+    autoload :Preloader,        'active_record/associations/preloader'
+    autoload :JoinDependency,   'active_record/associations/join_dependency'
+    autoload :AssociationScope, 'active_record/associations/association_scope'
+    autoload :AliasTracker,     'active_record/associations/alias_tracker'
+    autoload :JoinHelper,       'active_record/associations/join_helper'
 
     # Clears out the association cache.
     def clear_association_cache #:nodoc:
@@ -548,6 +549,49 @@ module ActiveRecord
     #     belongs_to :tag, :inverse_of => :taggings
     #   end
     #
+    # === Nested Associations
+    #
+    # You can actually specify *any* association with the <tt>:through</tt> option, including an
+    # association which has a <tt>:through</tt> option itself. For example:
+    #
+    #   class Author < ActiveRecord::Base
+    #     has_many :posts
+    #     has_many :comments, :through => :posts
+    #     has_many :commenters, :through => :comments
+    #   end
+    #
+    #   class Post < ActiveRecord::Base
+    #     has_many :comments
+    #   end
+    #
+    #   class Comment < ActiveRecord::Base
+    #     belongs_to :commenter
+    #   end
+    #
+    #   @author = Author.first
+    #   @author.commenters # => People who commented on posts written by the author
+    #
+    # An equivalent way of setting up this association this would be:
+    #
+    #   class Author < ActiveRecord::Base
+    #     has_many :posts
+    #     has_many :commenters, :through => :posts
+    #   end
+    #
+    #   class Post < ActiveRecord::Base
+    #     has_many :comments
+    #     has_many :commenters, :through => :comments
+    #   end
+    #
+    #   class Comment < ActiveRecord::Base
+    #     belongs_to :commenter
+    #   end
+    #
+    # When using nested association, you will not be able to modify the association because there
+    # is not enough information to know what modification to make. For example, if you tried to
+    # add a <tt>Commenter</tt> in the example above, there would be no way to tell how to set up the
+    # intermediate <tt>Post</tt> and <tt>Comment</tt> objects.
+    #
     # === Polymorphic Associations
     #
     # Polymorphic associations on models are not restricted on what types of models they
@@ -1068,10 +1112,10 @@ module ActiveRecord
       # [:as]
       #   Specifies a polymorphic interface (See <tt>belongs_to</tt>).
       # [:through]
-      #   Specifies a join model through which to perform the query.  Options for <tt>:class_name</tt>,
+      #   Specifies an association through which to perform the query. This can be any other type
+      #   of association, including other <tt>:through</tt> associations. Options for <tt>:class_name</tt>,
       #   <tt>:primary_key</tt> and <tt>:foreign_key</tt> are ignored, as the association uses the
-      #   source reflection. You can only use a <tt>:through</tt> query through a <tt>belongs_to</tt>,
-      #   <tt>has_one</tt> or <tt>has_many</tt> association on the join model.
+      #   source reflection.
       #
       #   If the association on the join model is a +belongs_to+, the collection can be modified
       #   and the records on the <tt>:through</tt> model will be automatically created and removed
@@ -1198,10 +1242,10 @@ module ActiveRecord
       #   you want to do a join but not include the joined columns. Do not forget to include the
       #   primary and foreign keys, otherwise it will raise an error.
       # [:through]
-      #   Specifies a Join Model through which to perform the query.  Options for <tt>:class_name</tt>
-      #   and <tt>:foreign_key</tt> are ignored, as the association uses the source reflection. You
-      #   can only use a <tt>:through</tt> query through a <tt>has_one</tt> or <tt>belongs_to</tt>
-      #   association on the join model.
+      #   Specifies a Join Model through which to perform the query.  Options for <tt>:class_name</tt>,
+      #   <tt>:primary_key</tt>, and <tt>:foreign_key</tt> are ignored, as the association uses the
+      #   source reflection. You can only use a <tt>:through</tt> query through a <tt>has_one</tt>
+      #   or <tt>belongs_to</tt> association on the join model.
       # [:source]
       #   Specifies the source association name used by <tt>has_one :through</tt> queries.
       #   Only use it if the name cannot be inferred from the association.
diff --git a/activerecord/lib/active_record/associations/alias_tracker.rb b/activerecord/lib/active_record/associations/alias_tracker.rb
new file mode 100644
index 0000000000..634dee2289
--- /dev/null
+++ b/activerecord/lib/active_record/associations/alias_tracker.rb
@@ -0,0 +1,85 @@
+require 'active_support/core_ext/string/conversions'
+
+module ActiveRecord
+  module Associations
+    # Keeps track of table aliases for ActiveRecord::Associations::ClassMethods::JoinDependency and
+    # ActiveRecord::Associations::ThroughAssociationScope
+    class AliasTracker # :nodoc:
+      attr_reader :aliases, :table_joins
+
+      # table_joins is an array of arel joins which might conflict with the aliases we assign here
+      def initialize(table_joins = [])
+        @aliases     = Hash.new
+        @table_joins = table_joins
+      end
+
+      def aliased_table_for(table_name, aliased_name = nil)
+        table_alias = aliased_name_for(table_name, aliased_name)
+
+        if table_alias == table_name
+          Arel::Table.new(table_name)
+        else
+          Arel::Table.new(table_name).alias(table_alias)
+        end
+      end
+
+      def aliased_name_for(table_name, aliased_name = nil)
+        aliased_name ||= table_name
+
+        initialize_count_for(table_name) if aliases[table_name].nil?
+
+        if aliases[table_name].zero?
+          # If it's zero, we can have our table_name
+          aliases[table_name] = 1
+          table_name
+        else
+          # Otherwise, we need to use an alias
+          aliased_name = connection.table_alias_for(aliased_name)
+
+          initialize_count_for(aliased_name) if aliases[aliased_name].nil?
+
+          # Update the count
+          aliases[aliased_name] += 1
+
+          if aliases[aliased_name] > 1
+            "#{truncate(aliased_name)}_#{aliases[aliased_name]}"
+          else
+            aliased_name
+          end
+        end
+      end
+
+      def pluralize(table_name)
+        ActiveRecord::Base.pluralize_table_names ? table_name.to_s.pluralize : table_name
+      end
+
+      private
+
+        def initialize_count_for(name)
+          aliases[name] = 0
+
+          unless Arel::Table === table_joins
+            # quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase
+            quoted_name = connection.quote_table_name(name).downcase
+
+            aliases[name] += table_joins.map { |join|
+              # Table names + table aliases
+              join.left.downcase.scan(
+                /join(?:\s+\w+)?\s+(\S+\s+)?#{quoted_name}\son/
+              ).size
+            }.sum
+          end
+
+          aliases[name]
+        end
+
+        def truncate(name)
+          name[0..connection.table_alias_length-3]
+        end
+
+        def connection
+          ActiveRecord::Base.connection
+        end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/association.rb b/activerecord/lib/active_record/associations/association.rb
index 25b4b9d90d..27c446b12c 100644
--- a/activerecord/lib/active_record/associations/association.rb
+++ b/activerecord/lib/active_record/associations/association.rb
@@ -93,23 +93,9 @@ module ActiveRecord
       # by scope.scoping { ... } or with_scope { ... } etc, which affects the scope which
       # actually gets built.
       def construct_scope
-        @association_scope = association_scope if klass
-      end
-
-      def association_scope
-        scope = klass.unscoped
-        scope = scope.create_with(creation_attributes)
-        scope = scope.apply_finder_options(options.slice(:readonly, :include))
-        scope = scope.where(interpolate(options[:conditions]))
-        if select = select_value
-          scope = scope.select(select)
+        if klass
+          @association_scope = AssociationScope.new(self).scope
         end
-        scope = scope.extending(*Array.wrap(options[:extend]))
-        scope.where(construct_owner_conditions)
-      end
-
-      def aliased_table
-        klass.arel_table
       end
 
       # Set the inverse association, if possible
@@ -174,42 +160,24 @@ module ActiveRecord
           end
         end
 
-        def select_value
-          options[:select]
-        end
-
-        # Implemented by (some) subclasses
         def creation_attributes
-          { }
-        end
-
-        # Returns a hash linking the owner to the association represented by the reflection
-        def construct_owner_attributes(reflection = reflection)
           attributes = {}
-          if reflection.macro == :belongs_to
-            attributes[reflection.association_primary_key] = owner[reflection.foreign_key]
-          else
+
+          if [:has_one, :has_many].include?(reflection.macro) && !options[:through]
             attributes[reflection.foreign_key] = owner[reflection.active_record_primary_key]
 
             if reflection.options[:as]
               attributes[reflection.type] = owner.class.base_class.name
             end
           end
-          attributes
-        end
 
-        # Builds an array of arel nodes from the owner attributes hash
-        def construct_owner_conditions(table = aliased_table, reflection = reflection)
-          conditions = construct_owner_attributes(reflection).map do |attr, value|
-            table[attr].eq(value)
-          end
-          table.create_and(conditions)
+          attributes
         end
 
         # Sets the owner attributes on the given record
         def set_owner_attributes(record)
           if owner.persisted?
-            construct_owner_attributes.each { |key, value| record[key] = value }
+            creation_attributes.each { |key, value| record[key] = value }
           end
         end
 
diff --git a/activerecord/lib/active_record/associations/association_scope.rb b/activerecord/lib/active_record/associations/association_scope.rb
new file mode 100644
index 0000000000..ab102b2b8f
--- /dev/null
+++ b/activerecord/lib/active_record/associations/association_scope.rb
@@ -0,0 +1,120 @@
+module ActiveRecord
+  module Associations
+    class AssociationScope #:nodoc:
+      include JoinHelper
+
+      attr_reader :association, :alias_tracker
+
+      delegate :klass, :owner, :reflection, :interpolate, :to => :association
+      delegate :chain, :conditions, :options, :source_options, :active_record, :to => :reflection
+
+      def initialize(association)
+        @association   = association
+        @alias_tracker = AliasTracker.new
+      end
+
+      def scope
+        scope = klass.unscoped
+        scope = scope.extending(*Array.wrap(options[:extend]))
+
+        # It's okay to just apply all these like this. The options will only be present if the
+        # association supports that option; this is enforced by the association builder.
+        scope = scope.apply_finder_options(options.slice(
+          :readonly, :include, :order, :limit, :joins, :group, :having, :offset))
+
+        if options[:through] && !options[:include]
+          scope = scope.includes(source_options[:include])
+        end
+
+        if select = select_value
+          scope = scope.select(select)
+        end
+
+        add_constraints(scope)
+      end
+
+      private
+
+      def select_value
+        select_value = options[:select]
+
+        if reflection.collection?
+          select_value ||= options[:uniq] && "DISTINCT #{reflection.quoted_table_name}.*"
+        end
+
+        if reflection.macro == :has_and_belongs_to_many
+          select_value ||= reflection.klass.arel_table[Arel.star]
+        end
+
+        select_value
+      end
+
+      def add_constraints(scope)
+        tables = construct_tables
+
+        chain.each_with_index do |reflection, i|
+          table, foreign_table = tables.shift, tables.first
+
+          if reflection.source_macro == :has_and_belongs_to_many
+            join_table = tables.shift
+
+            scope = scope.joins(join(
+              join_table,
+              table[reflection.active_record_primary_key].
+                eq(join_table[reflection.association_foreign_key])
+            ))
+
+            table, foreign_table = join_table, tables.first
+          end
+
+          if reflection.source_macro == :belongs_to
+            key         = reflection.association_primary_key
+            foreign_key = reflection.foreign_key
+          else
+            key         = reflection.foreign_key
+            foreign_key = reflection.active_record_primary_key
+          end
+
+          if reflection == chain.last
+            scope = scope.where(table[key].eq(owner[foreign_key]))
+
+            conditions[i].each do |condition|
+              if options[:through] && condition.is_a?(Hash)
+                condition = { table.name => condition }
+              end
+
+              scope = scope.where(interpolate(condition))
+            end
+          else
+            constraint = table[key].eq(foreign_table[foreign_key])
+            join       = join(foreign_table, constraint)
+
+            scope = scope.joins(join)
+
+            unless conditions[i].empty?
+              scope = scope.where(sanitize(conditions[i], table))
+            end
+          end
+        end
+
+        scope
+      end
+
+      def alias_suffix
+        reflection.name
+      end
+
+      def table_name_for(reflection)
+        if reflection == self.reflection
+          # If this is a polymorphic belongs_to, we want to get the klass from the
+          # association because it depends on the polymorphic_type attribute of
+          # the owner
+          klass.table_name
+        else
+          reflection.table_name
+        end
+      end
+
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb b/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb
index e40b32826a..4b48757da7 100644
--- a/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb
+++ b/activerecord/lib/active_record/associations/builder/has_and_belongs_to_many.rb
@@ -7,24 +7,24 @@ module ActiveRecord::Associations::Builder
     def build
       reflection = super
       check_validity(reflection)
-      redefine_destroy
+      define_after_destroy_method
       reflection
     end
 
     private
 
-      def redefine_destroy
-        # Don't use a before_destroy callback since users' before_destroy
-        # callbacks will be executed after the association is wiped out.
+      def define_after_destroy_method
         name = self.name
-        model.send(:include, Module.new {
-          class_eval <<-RUBY, __FILE__, __LINE__ + 1
-            def destroy          # def destroy
-              super              #   super
-              #{name}.clear      #   posts.clear
-            end                  # end
-          RUBY
-        })
+        model.send(:class_eval, <<-eoruby, __FILE__, __LINE__ + 1)
+          def #{after_destroy_method_name}
+            association(#{name.to_sym.inspect}).delete_all
+          end
+        eoruby
+        model.after_destroy after_destroy_method_name
+      end
+
+      def after_destroy_method_name
+        "has_and_belongs_to_many_after_destroy_for_#{name}"
       end
 
       # TODO: These checks should probably be moved into the Reflection, and we should not be
diff --git a/activerecord/lib/active_record/associations/collection_association.rb b/activerecord/lib/active_record/associations/collection_association.rb
index f3761bd2c7..9f4fc44cc6 100644
--- a/activerecord/lib/active_record/associations/collection_association.rb
+++ b/activerecord/lib/active_record/associations/collection_association.rb
@@ -331,11 +331,6 @@ module ActiveRecord
         @scopes_cache[method][args] ||= scoped.readonly(nil).send(method, *args)
       end
 
-      def association_scope
-        options = reflection.options.slice(:order, :limit, :joins, :group, :having, :offset)
-        super.apply_finder_options(options)
-      end
-
       def load_target
         if find_target?
           targets = []
@@ -373,14 +368,6 @@ module ActiveRecord
 
       private
 
-        def select_value
-          super || uniq_select_value
-        end
-
-        def uniq_select_value
-          options[:uniq] && "DISTINCT #{reflection.quoted_table_name}.*"
-        end
-
         def custom_counter_sql
           if options[:counter_sql]
             interpolate(options[:counter_sql])
diff --git a/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb b/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb
index 028630977d..217213808b 100644
--- a/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb
+++ b/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb
@@ -26,10 +26,6 @@ module ActiveRecord
         record
       end
 
-      def association_scope
-        super.joins(construct_joins)
-      end
-
       private
 
         def count_records
@@ -48,24 +44,6 @@ module ActiveRecord
           end
         end
 
-        def construct_joins
-          right = join_table
-          left  = reflection.klass.arel_table
-
-          condition = left[reflection.klass.primary_key].eq(
-            right[reflection.association_foreign_key])
-
-          right.create_join(right, right.create_on(condition))
-        end
-
-        def construct_owner_conditions
-          super(join_table)
-        end
-
-        def select_value
-          super || reflection.klass.arel_table[Arel.star]
-        end
-
         def invertible_for?(record)
           false
         end
diff --git a/activerecord/lib/active_record/associations/has_many_association.rb b/activerecord/lib/active_record/associations/has_many_association.rb
index cebf3e477a..78c5c4b870 100644
--- a/activerecord/lib/active_record/associations/has_many_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_association.rb
@@ -94,8 +94,6 @@ module ActiveRecord
             end
           end
         end
-
-        alias creation_attributes construct_owner_attributes
     end
   end
 end
diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb
index acac68fda5..9d2b29685b 100644
--- a/activerecord/lib/active_record/associations/has_many_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_through_association.rb
@@ -34,7 +34,9 @@ module ActiveRecord
       end
 
       def insert_record(record, validate = true)
+        ensure_not_nested
         return if record.new_record? && !record.save(:validate => validate)
+
         through_record(record).save!
         update_counter(1)
         record
@@ -59,6 +61,8 @@ module ActiveRecord
         end
 
         def build_record(attributes)
+          ensure_not_nested
+
           record = super(attributes)
 
           inverse = source_reflection.inverse_of
@@ -93,6 +97,8 @@ module ActiveRecord
         end
 
         def delete_records(records, method)
+          ensure_not_nested
+
           through = owner.association(through_reflection.name)
           scope   = through.scoped.where(construct_join_attributes(*records))
 
diff --git a/activerecord/lib/active_record/associations/has_one_association.rb b/activerecord/lib/active_record/associations/has_one_association.rb
index e13f97125f..1d2e8667e4 100644
--- a/activerecord/lib/active_record/associations/has_one_association.rb
+++ b/activerecord/lib/active_record/associations/has_one_association.rb
@@ -39,14 +39,8 @@ module ActiveRecord
         end
       end
 
-      def association_scope
-        super.order(options[:order])
-      end
-
       private
 
-        alias creation_attributes construct_owner_attributes
-
         # The reason that the save param for replace is false, if for create (not just build),
         # is because the setting of the foreign keys is actually handled by the scoping when
         # the record is instantiated, and so they are set straight away and do not need to be
diff --git a/activerecord/lib/active_record/associations/has_one_through_association.rb b/activerecord/lib/active_record/associations/has_one_through_association.rb
index d76d729303..fdf8ae1453 100644
--- a/activerecord/lib/active_record/associations/has_one_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_one_through_association.rb
@@ -12,6 +12,8 @@ module ActiveRecord
       private
 
         def create_through_record(record)
+          ensure_not_nested
+
           through_proxy  = owner.association(through_reflection.name)
           through_record = through_proxy.send(:load_target)
 
diff --git a/activerecord/lib/active_record/associations/join_dependency.rb b/activerecord/lib/active_record/associations/join_dependency.rb
index c7c3cf521c..504f25271c 100644
--- a/activerecord/lib/active_record/associations/join_dependency.rb
+++ b/activerecord/lib/active_record/associations/join_dependency.rb
@@ -5,18 +5,16 @@ module ActiveRecord
       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
+      attr_reader :join_parts, :reflections, :alias_tracker, :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
+        @active_record = base
+        @table_joins   = joins
+        @join_parts    = [JoinBase.new(base)]
+        @associations  = {}
+        @reflections   = []
+        @alias_tracker = AliasTracker.new(joins)
+        @alias_tracker.aliased_name_for(base.table_name) # Updates the count for base.table_name to 1
         build(associations)
       end
 
@@ -45,20 +43,6 @@ module ActiveRecord
         }.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 = {}
diff --git a/activerecord/lib/active_record/associations/join_dependency/join_association.rb b/activerecord/lib/active_record/associations/join_dependency/join_association.rb
index ebe39c35fe..4121a5b378 100644
--- a/activerecord/lib/active_record/associations/join_dependency/join_association.rb
+++ b/activerecord/lib/active_record/associations/join_dependency/join_association.rb
@@ -2,6 +2,8 @@ module ActiveRecord
   module Associations
     class JoinDependency # :nodoc:
       class JoinAssociation < JoinPart # :nodoc:
+        include JoinHelper
+
         # The reflection of the association represented
         attr_reader :reflection
 
@@ -18,10 +20,15 @@ module ActiveRecord
         attr_accessor :join_type
 
         # These implement abstract methods from the superclass
-        attr_reader :aliased_prefix, :aliased_table_name
+        attr_reader :aliased_prefix
+
+        attr_reader :tables
 
-        delegate :options, :through_reflection, :source_reflection, :to => :reflection
+        delegate :options, :through_reflection, :source_reflection, :chain, :to => :reflection
         delegate :table, :table_name, :to => :parent, :prefix => :parent
+        delegate :alias_tracker, :to => :join_dependency
+
+        alias :alias_suffix :parent_table_name
 
         def initialize(reflection, join_dependency, parent = nil)
           reflection.check_validity!
@@ -37,14 +44,7 @@ module ActiveRecord
           @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
-          )
+          @tables          = construct_tables.reverse
         end
 
         def ==(other)
@@ -60,219 +60,84 @@ module ActiveRecord
         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
+          tables        = @tables.dup
+          foreign_table = parent_table
+
+          # The chain starts with the target table, but we want to end with it here (makes
+          # more sense in this context), so we reverse
+          chain.reverse.each_with_index do |reflection, i|
+            table = tables.shift
+
+            case reflection.source_macro
+            when :belongs_to
+              key         = reflection.association_primary_key
+              foreign_key = reflection.foreign_key
+            when :has_and_belongs_to_many
+              # Join the join table first...
+              relation.from(join(
+                table,
+                table[reflection.foreign_key].
+                  eq(foreign_table[reflection.active_record_primary_key])
+              ))
+
+              foreign_table, table = table, tables.shift
+
+              key         = reflection.association_primary_key
+              foreign_key = reflection.association_foreign_key
+            else
+              key         = reflection.foreign_key
+              foreign_key = reflection.active_record_primary_key
+            end
 
-        def pluralize(table_name)
-          ActiveRecord::Base.pluralize_table_names ? table_name.to_s.pluralize : table_name
-        end
+            constraint = table[key].eq(foreign_table[foreign_key])
 
-        private
+            if reflection.klass.finder_needs_type_condition?
+              constraint = table.create_and([
+                constraint,
+                reflection.klass.send(:type_condition, table)
+              ])
+            end
 
-        def allocate_aliases
-          @aliased_table_name = aliased_table_name_for(table_name)
+            relation.from(join(table, constraint))
 
-          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
+            unless conditions[i].empty?
+              relation.where(sanitize(conditions[i], table))
+            end
 
-        def process_conditions(conditions, table_name)
-          if conditions.respond_to?(:to_proc)
-            conditions = instance_eval(&conditions)
+            # The current table in this iteration becomes the foreign table in the next
+            foreign_table = table
           end
 
-          Arel.sql(sanitize_sql(conditions, table_name))
+          relation
         end
 
-        def sanitize_sql(condition, table_name)
-          active_record.send(:sanitize_sql, condition, table_name)
+        def join_relation(joining_relation)
+          self.join_type = Arel::OuterJoin
+          joining_relation.joins(self)
         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
+        def table
+          tables.last
         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])
-          )
+        def aliased_table_name
+          table.table_alias || table.name
         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
+        def conditions
+          @conditions ||= reflection.conditions.reverse
         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
+        private
 
-          if through_reflection.macro == :belongs_to
-            jt_primary_key = through_reflection.foreign_key
-            jt_foreign_key = through_reflection.association_primary_key
+        def interpolate(conditions)
+          if conditions.respond_to?(:to_proc)
+            instance_eval(&conditions)
           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
+            conditions
           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
diff --git a/activerecord/lib/active_record/associations/join_helper.rb b/activerecord/lib/active_record/associations/join_helper.rb
new file mode 100644
index 0000000000..eae546e76e
--- /dev/null
+++ b/activerecord/lib/active_record/associations/join_helper.rb
@@ -0,0 +1,56 @@
+module ActiveRecord
+  module Associations
+    # Helper class module which gets mixed into JoinDependency::JoinAssociation and AssociationScope
+    module JoinHelper #:nodoc:
+
+      def join_type
+        Arel::InnerJoin
+      end
+
+      private
+
+      def construct_tables
+        tables = []
+        chain.each do |reflection|
+          tables << alias_tracker.aliased_table_for(
+            table_name_for(reflection),
+            table_alias_for(reflection, reflection != self.reflection)
+          )
+
+          if reflection.source_macro == :has_and_belongs_to_many
+            tables << alias_tracker.aliased_table_for(
+              (reflection.source_reflection || reflection).options[:join_table],
+              table_alias_for(reflection, true)
+            )
+          end
+        end
+        tables
+      end
+
+      def table_name_for(reflection)
+        reflection.table_name
+      end
+
+      def table_alias_for(reflection, join = false)
+        name = alias_tracker.pluralize(reflection.name)
+        name << "_#{alias_suffix}"
+        name << "_join" if join
+        name
+      end
+
+      def join(table, constraint)
+        table.create_join(table, table.create_on(constraint), join_type)
+      end
+
+      def sanitize(conditions, table)
+        conditions = conditions.map do |condition|
+          condition = active_record.send(:sanitize_sql, interpolate(condition), table.table_alias || table.name)
+          condition = Arel.sql(condition) unless condition.is_a?(Arel::Node)
+          condition
+        end
+
+        conditions.length == 1 ? conditions.first : Arel::Nodes::And.new(conditions)
+      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
index d630fc4c63..ad6374d09a 100644
--- a/activerecord/lib/active_record/associations/preloader/through_association.rb
+++ b/activerecord/lib/active_record/associations/preloader/through_association.rb
@@ -19,8 +19,9 @@ module ActiveRecord
             source_reflection.name, options
           ).run
 
-          through_records.each do |owner, owner_through_records|
-            owner_through_records.map! { |r| r.send(source_reflection.name) }.flatten!
+          through_records.each do |owner, records|
+            records.map! { |r| r.send(source_reflection.name) }.flatten!
+            records.compact!
           end
         end
 
diff --git a/activerecord/lib/active_record/associations/through_association.rb b/activerecord/lib/active_record/associations/through_association.rb
index e1d60ccb17..e6ab628719 100644
--- a/activerecord/lib/active_record/associations/through_association.rb
+++ b/activerecord/lib/active_record/associations/through_association.rb
@@ -3,79 +3,24 @@ module ActiveRecord
   module Associations
     module ThroughAssociation #:nodoc:
 
-      delegate :source_options, :through_options, :source_reflection, :through_reflection, :to => :reflection
+      delegate :source_reflection, :through_reflection, :chain, :to => :reflection
 
       protected
 
+        # We merge in these scopes for two reasons:
+        #
+        #   1. To get the default_scope conditions for any of the other reflections in the chain
+        #   2. To get the type conditions for any STI models in the chain
         def target_scope
-          super.merge(through_reflection.klass.scoped)
-        end
-
-        def association_scope
-          scope = super.joins(construct_joins)
-          scope = add_conditions(scope)
-          unless options[:include]
-            scope = scope.includes(source_options[:include])
+          scope = super
+          chain[1..-1].each do |reflection|
+            scope = scope.merge(reflection.klass.scoped)
           end
           scope
         end
 
       private
 
-        # This scope affects the creation of the associated records (not the join records). At the
-        # moment we only support creating on a :through association when the source reflection is a
-        # belongs_to. Thus it's not necessary to set a foreign key on the associated record(s), so
-        # this scope has can legitimately be empty.
-        def creation_attributes
-          { }
-        end
-
-        def aliased_through_table
-          name = through_reflection.table_name
-
-          reflection.table_name == name ?
-            through_reflection.klass.arel_table.alias(name + "_join") :
-            through_reflection.klass.arel_table
-        end
-
-        def construct_owner_conditions
-          super(aliased_through_table, through_reflection)
-        end
-
-        def construct_joins
-          right = aliased_through_table
-          left  = reflection.klass.arel_table
-
-          conditions = []
-
-          if source_reflection.macro == :belongs_to
-            reflection_primary_key = source_reflection.association_primary_key
-            source_primary_key     = source_reflection.foreign_key
-
-            if options[:source_type]
-              column = source_reflection.foreign_type
-              conditions <<
-                right[column].eq(options[:source_type])
-            end
-          else
-            reflection_primary_key = source_reflection.foreign_key
-            source_primary_key     = source_reflection.active_record_primary_key
-
-            if source_options[:as]
-              column = "#{source_options[:as]}_type"
-              conditions <<
-                left[column].eq(through_reflection.klass.name)
-            end
-          end
-
-          conditions <<
-            left[reflection_primary_key].eq(right[source_primary_key])
-
-          right.create_join(
-            right,
-            right.create_on(right.create_and(conditions)))
-        end
-
         # Construct attributes for :through pointing to owner and associate. This is used by the
         # methods which create and delete records on the association.
         #
@@ -112,37 +57,8 @@ module ActiveRecord
           end
         end
 
-        # The reason that we are operating directly on the scope here (rather than passing
-        # back some arel conditions to be added to the scope) is because scope.where([x, y])
-        # has a different meaning to scope.where(x).where(y) - the first version might
-        # perform some substitution if x is a string.
-        def add_conditions(scope)
-          unless through_reflection.klass.descends_from_active_record?
-            scope = scope.where(through_reflection.klass.send(:type_condition))
-          end
-
-          scope = scope.where(interpolate(source_options[:conditions]))
-          scope.where(through_conditions)
-        end
-
-        # If there is a hash of conditions then we make sure the keys are scoped to the
-        # through table name if left ambiguous.
-        def through_conditions
-          conditions = interpolate(through_options[:conditions])
-
-          if conditions.is_a?(Hash)
-            Hash[conditions.map { |key, value|
-              unless value.is_a?(Hash) || key.to_s.include?('.')
-                key = aliased_through_table.name + '.' + key.to_s
-              end
-
-              [key, value]
-            }]
-          else
-            conditions
-          end
-        end
-
+        # Note: this does not capture all cases, for example it would be crazy to try to
+        # properly support stale-checking for nested associations.
         def stale_state
           if through_reflection.macro == :belongs_to
             owner[through_reflection.foreign_key].to_s
@@ -153,6 +69,12 @@ module ActiveRecord
           through_reflection.macro == :belongs_to &&
           !owner[through_reflection.foreign_key].nil?
         end
+
+        def ensure_not_nested
+          if reflection.nested?
+            raise HasManyThroughNestedAssociationsAreReadonly.new(owner, reflection)
+          end
+        end
     end
   end
 end
diff --git a/activerecord/lib/active_record/attribute_methods/read.rb b/activerecord/lib/active_record/attribute_methods/read.rb
index ab86d8bad1..69d5cd83f1 100644
--- a/activerecord/lib/active_record/attribute_methods/read.rb
+++ b/activerecord/lib/active_record/attribute_methods/read.rb
@@ -70,7 +70,14 @@ module ActiveRecord
             if cache_attribute?(attr_name)
               access_code = "@attributes_cache['#{attr_name}'] ||= (#{access_code})"
             end
-            generated_attribute_methods.module_eval("def _#{symbol}; #{access_code}; end; alias #{symbol} _#{symbol}", __FILE__, __LINE__)
+            if symbol =~ /^[a-zA-Z_]\w*[!?=]?$/
+              generated_attribute_methods.module_eval("def _#{symbol}; #{access_code}; end; alias #{symbol} _#{symbol}", __FILE__, __LINE__)
+            else
+              generated_attribute_methods.module_eval do
+                define_method("_#{symbol}") { eval(access_code) }
+                alias_method(symbol, "_#{symbol}")
+              end
+            end
           end
       end
 
diff --git a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
index 76218d2a73..6aac96df6f 100644
--- a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
+++ b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
@@ -21,9 +21,9 @@ module ActiveRecord
           def define_method_attribute(attr_name)
             if create_time_zone_conversion_attribute?(attr_name, columns_hash[attr_name])
               method_body, line = <<-EOV, __LINE__ + 1
-                def _#{attr_name}(reload = false)
+                def _#{attr_name}
                   cached = @attributes_cache['#{attr_name}']
-                  return cached if cached && !reload
+                  return cached if cached
                   time = _read_attribute('#{attr_name}')
                   @attributes_cache['#{attr_name}'] = time.acts_like?(:time) ? time.in_time_zone : time
                 end
@@ -41,12 +41,13 @@ module ActiveRecord
             if create_time_zone_conversion_attribute?(attr_name, columns_hash[attr_name])
               method_body, line = <<-EOV, __LINE__ + 1
                 def #{attr_name}=(original_time)
-                  time = original_time.dup unless original_time.nil?
+                  time = original_time
                   unless time.acts_like?(:time)
                     time = time.is_a?(String) ? Time.zone.parse(time) : time.to_time rescue time
                   end
                   time = time.in_time_zone rescue nil if time
-                  write_attribute(:#{attr_name}, (time || original_time))
+                  write_attribute(:#{attr_name}, original_time)
+                  @attributes_cache["#{attr_name}"] = time
                 end
               EOV
               generated_attribute_methods.module_eval(method_body, __FILE__, line)
diff --git a/activerecord/lib/active_record/attribute_methods/write.rb b/activerecord/lib/active_record/attribute_methods/write.rb
index 6a593a7e0e..3c4dab304e 100644
--- a/activerecord/lib/active_record/attribute_methods/write.rb
+++ b/activerecord/lib/active_record/attribute_methods/write.rb
@@ -10,7 +10,13 @@ module ActiveRecord
       module ClassMethods
         protected
           def define_method_attribute=(attr_name)
-            generated_attribute_methods.module_eval("def #{attr_name}=(new_value); write_attribute('#{attr_name}', new_value); end", __FILE__, __LINE__)
+            if attr_name =~ /^[a-zA-Z_]\w*[!?=]?$/
+              generated_attribute_methods.module_eval("def #{attr_name}=(new_value); write_attribute('#{attr_name}', new_value); end", __FILE__, __LINE__)
+            else
+              generated_attribute_methods.send(:define_method, "#{attr_name}=") do |new_value|
+                write_attribute(attr_name, new_value)
+              end
+            end
           end
       end
 
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index a5e1c91f47..b778b0c0f0 100644
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -973,8 +973,8 @@ module ActiveRecord #:nodoc:
           relation
         end
 
-        def type_condition
-          sti_column = arel_table[inheritance_column.to_sym]
+        def type_condition(table = arel_table)
+          sti_column = table[inheritance_column.to_sym]
           sti_names  = ([self] + descendants).map { |model| model.sti_name }
 
           sti_column.in(sti_names)
@@ -995,7 +995,7 @@ module ActiveRecord #:nodoc:
             if parent < ActiveRecord::Base && !parent.abstract_class?
               contained = parent.table_name
               contained = contained.singularize if parent.pluralize_table_names
-              contained << '_'
+              contained += '_'
             end
             "#{full_table_name_prefix}#{contained}#{undecorated_table_name(name)}#{table_name_suffix}"
           else
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
index 5c1ce173c8..a3082b8f01 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
@@ -237,7 +237,6 @@ module ActiveRecord
       #  add_limit_offset!('SELECT * FROM suppliers', {:limit => 10, :offset => 50})
       # generates
       #  SELECT * FROM suppliers LIMIT 10 OFFSET 50
-
       def add_limit_offset!(sql, options)
         if limit = options[:limit]
           sql << " LIMIT #{sanitize_limit(limit)}"
@@ -272,6 +271,10 @@ module ActiveRecord
         execute "INSERT INTO #{quote_table_name(table_name)} (#{key_list.join(', ')}) VALUES (#{value_list.join(', ')})", 'Fixture Insert'
       end
 
+      def null_insert_value
+        Arel.sql 'DEFAULT'
+      end
+
       def empty_insert_statement_value
         "VALUES(DEFAULT)"
       end
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index 368c5b2023..e1186209d3 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -504,14 +504,28 @@ module ActiveRecord
         show_variable 'collation_database'
       end
 
-      def tables(name = nil) #:nodoc:
+      def tables(name = nil, database = nil) #:nodoc:
         tables = []
-        result = execute("SHOW TABLES", name)
+        result = execute(["SHOW TABLES", database].compact.join(' IN '), name)
         result.each { |field| tables << field[0] }
         result.free
         tables
       end
 
+      def table_exists?(name)
+        return true if super
+
+        name          = name.to_s
+        schema, table = name.split('.', 2)
+
+        unless table # A table was provided without a schema
+          table  = schema
+          schema = nil
+        end
+
+        tables(nil, schema).include? table
+      end
+
       def drop_table(table_name, options = {})
         super(table_name, options)
       end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 576450bc3a..5a830a50fb 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -453,7 +453,7 @@ module ActiveRecord
           # If a pk is given, fallback to default sequence name.
           # Don't fetch last insert id for a table without a pk.
           if pk && sequence_name ||= default_sequence_name(table, pk)
-            last_insert_id(table, sequence_name)
+            last_insert_id(sequence_name)
           end
         end
       end
@@ -1038,8 +1038,9 @@ module ActiveRecord
         end
 
         # Returns the current ID of a table's sequence.
-        def last_insert_id(table, sequence_name) #:nodoc:
-          Integer(select_value("SELECT currval('#{sequence_name}')"))
+        def last_insert_id(sequence_name) #:nodoc:
+          r = exec_query("SELECT currval($1)", 'SQL', [[nil, sequence_name]])
+          Integer(r.rows.first.first)
         end
 
         # Executes a SELECT query and returns the results, performing any data type
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index c2cd9e8d5e..c3a7b039ff 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -34,6 +34,14 @@ module ActiveRecord
 
   module ConnectionAdapters #:nodoc:
     class SQLite3Adapter < SQLiteAdapter # :nodoc:
+      def quote(value, column = nil)
+        if value.kind_of?(String) && column && column.type == :binary && column.class.respond_to?(:string_to_binary)
+          s = column.class.string_to_binary(value).unpack("H*")[0]
+          "x'#{s}'"
+        else
+          super
+        end
+      end
 
       # Returns the current database encoding format as a string, eg: 'UTF-8'
       def encoding
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
index 9ee6b88ab6..ae61d6ce94 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
@@ -336,6 +336,10 @@ module ActiveRecord
         alter_table(table_name, :rename => {column_name.to_s => new_column_name.to_s})
       end
 
+      def null_insert_value
+        Arel.sql 'NULL'
+      end
+
       def empty_insert_statement_value
         "VALUES(NULL)"
       end
diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb
index df7b22080c..17a64b6e86 100644
--- a/activerecord/lib/active_record/persistence.rb
+++ b/activerecord/lib/active_record/persistence.rb
@@ -270,17 +270,9 @@ module ActiveRecord
     # Creates a record with values matching those of the instance attributes
     # and returns its id.
     def create
-      if id.nil? && connection.prefetch_primary_key?(self.class.table_name)
-        self.id = connection.next_sequence_value(self.class.sequence_name)
-      end
-
       attributes_values = arel_attributes_values(!id.nil?)
 
-      new_id = if attributes_values.empty?
-        self.class.unscoped.insert connection.empty_insert_statement_value
-      else
-        self.class.unscoped.insert attributes_values
-      end
+      new_id = self.class.unscoped.insert attributes_values
 
       self.id ||= new_id
 
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index 5de08953f9..e801bc4afa 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -262,16 +262,30 @@ module ActiveRecord
       end
 
       def through_reflection
-        false
-      end
-
-      def through_reflection_foreign_key
+        nil
       end
 
       def source_reflection
         nil
       end
 
+      # A chain of reflections from this one back to the owner. For more see the explanation in
+      # ThroughReflection.
+      def chain
+        [self]
+      end
+
+      # An array of arrays of conditions. Each item in the outside array corresponds to a reflection
+      # in the #chain. The inside arrays are simply conditions (and each condition may itself be
+      # a hash, array, arel predicate, etc...)
+      def conditions
+        conditions = [options[:conditions]].compact
+        conditions << { type => active_record.base_class.name } if options[:as]
+        [conditions]
+      end
+
+      alias :source_macro :macro
+
       def has_inverse?
         @options[:inverse_of]
       end
@@ -363,7 +377,7 @@ 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
+      delegate :foreign_key, :foreign_type, :association_foreign_key, :active_record_primary_key, :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>.
@@ -392,6 +406,88 @@ module ActiveRecord
         @through_reflection ||= active_record.reflect_on_association(options[:through])
       end
 
+      # Returns an array of reflections which are involved in this association. Each item in the
+      # array corresponds to a table which will be part of the query for this association.
+      #
+      # The chain is built by recursively calling #chain on the source reflection and the through
+      # reflection. The base case for the recursion is a normal association, which just returns
+      # [self] as its #chain.
+      def chain
+        @chain ||= begin
+          chain = source_reflection.chain + through_reflection.chain
+          chain[0] = self # Use self so we don't lose the information from :source_type
+          chain
+        end
+      end
+
+      # Consider the following example:
+      #
+      #   class Person
+      #     has_many :articles
+      #     has_many :comment_tags, :through => :articles
+      #   end
+      #
+      #   class Article
+      #     has_many :comments
+      #     has_many :comment_tags, :through => :comments, :source => :tags
+      #   end
+      #
+      #   class Comment
+      #     has_many :tags
+      #   end
+      #
+      # There may be conditions on Person.comment_tags, Article.comment_tags and/or Comment.tags,
+      # but only Comment.tags will be represented in the #chain. So this method creates an array
+      # of conditions corresponding to the chain. Each item in the #conditions array corresponds
+      # to an item in the #chain, and is itself an array of conditions from an arbitrary number
+      # of relevant reflections, plus any :source_type or polymorphic :as constraints.
+      def conditions
+        @conditions ||= begin
+          conditions = source_reflection.conditions
+
+          # Add to it the conditions from this reflection if necessary.
+          conditions.first << options[:conditions] if options[:conditions]
+
+          through_conditions = through_reflection.conditions
+
+          if options[:source_type]
+            through_conditions.first << { foreign_type => options[:source_type] }
+          end
+
+          # Recursively fill out the rest of the array from the through reflection
+          conditions += through_conditions
+
+          # And return
+          conditions
+        end
+      end
+
+      # The macro used by the source association
+      def source_macro
+        source_reflection.source_macro
+      end
+
+      # A through association is nested iff there would be more than one join table
+      def nested?
+        chain.length > 2 || through_reflection.macro == :has_and_belongs_to_many
+      end
+
+      # We want to use the klass from this reflection, rather than just delegate straight to
+      # the source_reflection, because the source_reflection may be polymorphic. We still
+      # need to respect the source_reflection's :primary_key option, though.
+      def association_primary_key
+        @association_primary_key ||= begin
+          # Get the "actual" source reflection if the immediate source reflection has a
+          # source reflection itself
+          source_reflection = self.source_reflection
+          while source_reflection.source_reflection
+            source_reflection = source_reflection.source_reflection
+          end
+
+          source_reflection.options[:primary_key] || klass.primary_key
+        end
+      end
+
       # Gets an array of possible <tt>:through</tt> source reflection names:
       #
       #   [:singularized, :pluralized]
@@ -429,10 +525,6 @@ module ActiveRecord
           raise HasManyThroughAssociationPolymorphicSourceError.new(active_record.name, self, source_reflection)
         end
 
-        unless [:belongs_to, :has_many, :has_one].include?(source_reflection.macro) && source_reflection.options[:through].nil?
-          raise HasManyThroughSourceAssociationMacroError.new(self)
-        end
-
         if macro == :has_one && through_reflection.collection?
           raise HasOneThroughCantAssociateThroughCollection.new(active_record.name, self, through_reflection)
         end
@@ -440,14 +532,6 @@ module ActiveRecord
         check_validity_of_inverse!
       end
 
-      def through_reflection_primary_key
-        through_reflection.belongs_to? ? through_reflection.klass.primary_key : through_reflection.foreign_key
-      end
-
-      def through_reflection_foreign_key
-        through_reflection.foreign_key if through_reflection.belongs_to?
-      end
-
       private
         def derive_class_name
           # get the class_name of the belongs_to association of the through reflection
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index 371403f510..8e545f9cad 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -30,15 +30,26 @@ module ActiveRecord
     end
 
     def insert(values)
-      im = arel.compile_insert values
-      im.into @table
-
       primary_key_value = nil
 
       if primary_key && Hash === values
         primary_key_value = values[values.keys.find { |k|
           k.name == primary_key
         }]
+
+        if !primary_key_value && connection.prefetch_primary_key?(klass.table_name)
+          primary_key_value = connection.next_sequence_value(klass.sequence_name)
+          values[klass.arel_table[klass.primary_key]] = primary_key_value
+        end
+      end
+
+      im = arel.create_insert
+      im.into @table
+
+      if values.empty? # empty insert
+        im.values = im.create_values [connection.null_insert_value], []
+      else
+        im.insert values
       end
 
       @klass.connection.insert(
diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index 426000fde1..563843f3cc 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -123,6 +123,12 @@ module ActiveRecord
       end
     end
 
+    # Same as +first+ but raises <tt>ActiveRecord::RecordNotFound</tt> if no record
+    # is found. Note that <tt>first!</tt> accepts no arguments.
+    def first!
+      first or raise RecordNotFound
+    end
+
     # A convenience wrapper for <tt>find(:last, *args)</tt>. You can pass in all the
     # same arguments to this method as you can to <tt>find(:last)</tt>.
     def last(*args)
@@ -137,6 +143,12 @@ module ActiveRecord
       end
     end
 
+    # Same as +last+ but raises <tt>ActiveRecord::RecordNotFound</tt> if no record
+    # is found. Note that <tt>last!</tt> accepts no arguments.
+    def last!
+      last or raise RecordNotFound
+    end
+
     # A convenience wrapper for <tt>find(:all, *args)</tt>. You can pass in all the
     # same arguments to this method as you can to <tt>find(:all)</tt>.
     def all(*args)
diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb
index cd1d7108b3..9470e7c6c5 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -261,7 +261,7 @@ module ActiveRecord
       )
 
       join_nodes.each do |join|
-        join_dependency.table_aliases[join.left.name.downcase] = 1
+        join_dependency.alias_tracker.aliased_name_for(join.left.name.downcase)
       end
 
       join_dependency.graft(*stashed_association_joins)
diff --git a/activerecord/lib/active_record/relation/spawn_methods.rb b/activerecord/lib/active_record/relation/spawn_methods.rb
index 4150e36a9a..128e0fbd86 100644
--- a/activerecord/lib/active_record/relation/spawn_methods.rb
+++ b/activerecord/lib/active_record/relation/spawn_methods.rb
@@ -79,6 +79,9 @@ module ActiveRecord
         result.send(:"#{method}_value=", send(:"#{method}_value"))
       end
 
+      # Apply scope extension modules
+      result.send(:apply_modules, extensions)
+
       result
     end
 
@@ -100,6 +103,9 @@ module ActiveRecord
         result.send(:"#{method}_value=", send(:"#{method}_value"))
       end
 
+      # Apply scope extension modules
+      result.send(:apply_modules, extensions)
+
       result
     end
 
diff --git a/activerecord/test/cases/adapters/mysql/schema_test.rb b/activerecord/test/cases/adapters/mysql/schema_test.rb
new file mode 100644
index 0000000000..c6c1d1dad5
--- /dev/null
+++ b/activerecord/test/cases/adapters/mysql/schema_test.rb
@@ -0,0 +1,36 @@
+require "cases/helper"
+require 'models/post'
+require 'models/comment'
+
+module ActiveRecord
+  module ConnectionAdapters
+    class MysqlSchemaTest < ActiveRecord::TestCase
+      fixtures :posts
+
+      def setup
+        @connection = ActiveRecord::Base.connection
+        db          = Post.connection_pool.spec.config[:database]
+        table       = Post.table_name
+        @db_name    = db
+
+        @omgpost = Class.new(Post) do
+          set_table_name "#{db}.#{table}"
+          def self.name; 'Post'; end
+        end
+      end
+
+      def test_schema
+        assert @omgpost.find(:first)
+      end
+
+      def test_table_exists?
+        name = @omgpost.table_name
+        assert @connection.table_exists?(name), "#{name} table should exist"
+      end
+
+      def test_table_exists_wrong_schema
+        assert(!@connection.table_exists?("#{@db_name}.zomg"), "table should not exist")
+      end
+    end if current_adapter?(:MysqlAdapter)
+  end
+end
diff --git a/activerecord/test/cases/adapters/sqlite/sqlite_adapter_test.rb b/activerecord/test/cases/adapters/sqlite/sqlite_adapter_test.rb
index ce0b2f5f5b..d1fc470907 100644
--- a/activerecord/test/cases/adapters/sqlite/sqlite_adapter_test.rb
+++ b/activerecord/test/cases/adapters/sqlite/sqlite_adapter_test.rb
@@ -1,8 +1,13 @@
+# encoding: utf-8
 require "cases/helper"
+require 'models/binary'
 
 module ActiveRecord
   module ConnectionAdapters
     class SQLiteAdapterTest < ActiveRecord::TestCase
+      class DualEncoding < ActiveRecord::Base
+      end
+
       def setup
         @ctx = Base.sqlite3_connection :database => ':memory:',
                                       :adapter => 'sqlite3',
@@ -15,6 +20,20 @@ module ActiveRecord
         eosql
       end
 
+      def test_quote_binary_column_escapes_it
+        DualEncoding.connection.execute(<<-eosql)
+          CREATE TABLE dual_encodings (
+            id integer PRIMARY KEY AUTOINCREMENT,
+            name string,
+            data binary
+          )
+        eosql
+        str = "\x80".force_encoding("ASCII-8BIT")
+        binary = DualEncoding.new :name => 'いただきます！', :data => str
+        binary.save!
+        assert_equal str, binary.data
+      end
+
       def test_execute
         @ctx.execute "INSERT INTO items (number) VALUES (10)"
         records = @ctx.execute "SELECT * FROM items"
diff --git a/activerecord/test/cases/associations/cascaded_eager_loading_test.rb b/activerecord/test/cases/associations/cascaded_eager_loading_test.rb
index 0742e311d9..39e8a7960a 100644
--- a/activerecord/test/cases/associations/cascaded_eager_loading_test.rb
+++ b/activerecord/test/cases/associations/cascaded_eager_loading_test.rb
@@ -15,17 +15,17 @@ class CascadedEagerLoadingTest < ActiveRecord::TestCase
 
   def test_eager_association_loading_with_cascaded_two_levels
     authors = Author.find(:all, :include=>{:posts=>:comments}, :order=>"authors.id")
-    assert_equal 2, authors.size
+    assert_equal 3, authors.size
     assert_equal 5, authors[0].posts.size
-    assert_equal 1, authors[1].posts.size
+    assert_equal 3, authors[1].posts.size
     assert_equal 10, authors[0].posts.collect{|post| post.comments.size }.inject(0){|sum,i| sum+i}
   end
 
   def test_eager_association_loading_with_cascaded_two_levels_and_one_level
     authors = Author.find(:all, :include=>[{:posts=>:comments}, :categorizations], :order=>"authors.id")
-    assert_equal 2, authors.size
+    assert_equal 3, authors.size
     assert_equal 5, authors[0].posts.size
-    assert_equal 1, authors[1].posts.size
+    assert_equal 3, authors[1].posts.size
     assert_equal 10, authors[0].posts.collect{|post| post.comments.size }.inject(0){|sum,i| sum+i}
     assert_equal 1, authors[0].categorizations.size
     assert_equal 2, authors[1].categorizations.size
@@ -51,24 +51,24 @@ class CascadedEagerLoadingTest < ActiveRecord::TestCase
     categories = Category.joins(:categorizations).includes([{:posts=>:comments}, :authors])
 
     assert_nothing_raised do
-      assert_equal 2, categories.count
-      assert_equal 2, categories.all.uniq.size # Must uniq since instantiating with inner joins will get dupes
+      assert_equal 3, categories.count
+      assert_equal 3, categories.all.uniq.size # Must uniq since instantiating with inner joins will get dupes
     end
   end
 
   def test_cascaded_eager_association_loading_with_duplicated_includes
     categories = Category.includes(:categorizations).includes(:categorizations => :author).where("categorizations.id is not null")
     assert_nothing_raised do
-      assert_equal 2, categories.count
-      assert_equal 2, categories.all.size
+      assert_equal 3, categories.count
+      assert_equal 3, categories.all.size
     end
   end
 
   def test_cascaded_eager_association_loading_with_twice_includes_edge_cases
     categories = Category.includes(:categorizations => :author).includes(:categorizations => :post).where("posts.id is not null")
     assert_nothing_raised do
-      assert_equal 2, categories.count
-      assert_equal 2, categories.all.size
+      assert_equal 3, categories.count
+      assert_equal 3, categories.all.size
     end
   end
 
@@ -81,15 +81,15 @@ class CascadedEagerLoadingTest < ActiveRecord::TestCase
 
   def test_eager_association_loading_with_cascaded_two_levels_with_two_has_many_associations
     authors = Author.find(:all, :include=>{:posts=>[:comments, :categorizations]}, :order=>"authors.id")
-    assert_equal 2, authors.size
+    assert_equal 3, authors.size
     assert_equal 5, authors[0].posts.size
-    assert_equal 1, authors[1].posts.size
+    assert_equal 3, authors[1].posts.size
     assert_equal 10, authors[0].posts.collect{|post| post.comments.size }.inject(0){|sum,i| sum+i}
   end
 
   def test_eager_association_loading_with_cascaded_two_levels_and_self_table_reference
     authors = Author.find(:all, :include=>{:posts=>[:comments, :author]}, :order=>"authors.id")
-    assert_equal 2, authors.size
+    assert_equal 3, authors.size
     assert_equal 5, authors[0].posts.size
     assert_equal authors(:david).name, authors[0].name
     assert_equal [authors(:david).name], authors[0].posts.collect{|post| post.author.name}.uniq
@@ -157,9 +157,9 @@ class CascadedEagerLoadingTest < ActiveRecord::TestCase
 
   def test_eager_association_loading_where_first_level_returns_nil
     authors = Author.find(:all, :include => {:post_about_thinking => :comments}, :order => 'authors.id DESC')
-    assert_equal [authors(:mary), authors(:david)], authors
+    assert_equal [authors(:bob), authors(:mary), authors(:david)], authors
     assert_no_queries do
-      authors[1].post_about_thinking.comments.first
+      authors[2].post_about_thinking.comments.first
     end
   end
 end
diff --git a/activerecord/test/cases/associations/eager_test.rb b/activerecord/test/cases/associations/eager_test.rb
index 48406a9b98..40c82f2fb8 100644
--- a/activerecord/test/cases/associations/eager_test.rb
+++ b/activerecord/test/cases/associations/eager_test.rb
@@ -68,8 +68,8 @@ class EagerAssociationTest < ActiveRecord::TestCase
 
   def test_with_ordering
     list = Post.find(:all, :include => :comments, :order => "posts.id DESC")
-    [:eager_other, :sti_habtm, :sti_post_and_comments, :sti_comments,
-     :authorless, :thinking, :welcome
+    [:other_by_mary, :other_by_bob, :misc_by_mary, :misc_by_bob, :eager_other,
+     :sti_habtm, :sti_post_and_comments, :sti_comments, :authorless, :thinking, :welcome
     ].each_with_index do |post, index|
       assert_equal posts(post), list[index]
     end
@@ -97,25 +97,25 @@ class EagerAssociationTest < ActiveRecord::TestCase
   def test_preloading_has_many_in_multiple_queries_with_more_ids_than_database_can_handle
     Post.connection.expects(:in_clause_length).at_least_once.returns(5)
     posts = Post.find(:all, :include=>:comments)
-    assert_equal 7, posts.size
+    assert_equal 11, posts.size
   end
 
   def test_preloading_has_many_in_one_queries_when_database_has_no_limit_on_ids_it_can_handle
     Post.connection.expects(:in_clause_length).at_least_once.returns(nil)
     posts = Post.find(:all, :include=>:comments)
-    assert_equal 7, posts.size
+    assert_equal 11, posts.size
   end
 
   def test_preloading_habtm_in_multiple_queries_with_more_ids_than_database_can_handle
     Post.connection.expects(:in_clause_length).at_least_once.returns(5)
     posts = Post.find(:all, :include=>:categories)
-    assert_equal 7, posts.size
+    assert_equal 11, posts.size
   end
 
   def test_preloading_habtm_in_one_queries_when_database_has_no_limit_on_ids_it_can_handle
     Post.connection.expects(:in_clause_length).at_least_once.returns(nil)
     posts = Post.find(:all, :include=>:categories)
-    assert_equal 7, posts.size
+    assert_equal 11, posts.size
   end
 
   def test_load_associated_records_in_one_query_when_adapter_has_no_limit
diff --git a/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb b/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb
index dc382c3007..73d02c9676 100644
--- a/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb
@@ -642,12 +642,12 @@ class HasAndBelongsToManyAssociationsTest < ActiveRecord::TestCase
   def test_find_grouped
     all_posts_from_category1 = Post.find(:all, :conditions => "category_id = 1", :joins => :categories)
     grouped_posts_of_category1 = Post.find(:all, :conditions => "category_id = 1", :group => "author_id", :select => 'count(posts.id) as posts_count', :joins => :categories)
-    assert_equal 4, all_posts_from_category1.size
-    assert_equal 1, grouped_posts_of_category1.size
+    assert_equal 5, all_posts_from_category1.size
+    assert_equal 2, grouped_posts_of_category1.size
   end
 
   def test_find_scoped_grouped
-    assert_equal 4, categories(:general).posts_grouped_by_title.size
+    assert_equal 5, categories(:general).posts_grouped_by_title.size
     assert_equal 1, categories(:technology).posts_grouped_by_title.size
   end
 
diff --git a/activerecord/test/cases/associations/has_many_through_associations_test.rb b/activerecord/test/cases/associations/has_many_through_associations_test.rb
index efdecd4b09..9adaebe924 100644
--- a/activerecord/test/cases/associations/has_many_through_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_through_associations_test.rb
@@ -17,9 +17,10 @@ require 'models/developer'
 require 'models/subscriber'
 require 'models/book'
 require 'models/subscription'
-require 'models/categorization'
-require 'models/category'
 require 'models/essay'
+require 'models/category'
+require 'models/owner'
+require 'models/categorization'
 require 'models/member'
 require 'models/membership'
 require 'models/club'
@@ -27,7 +28,7 @@ require 'models/club'
 class HasManyThroughAssociationsTest < ActiveRecord::TestCase
   fixtures :posts, :readers, :people, :comments, :authors, :categories, :taggings, :tags,
            :owners, :pets, :toys, :jobs, :references, :companies, :members, :author_addresses,
-           :subscribers, :books, :subscriptions, :developers, :categorizations
+           :subscribers, :books, :subscriptions, :developers, :categorizations, :essays
 
   # Dummies to force column loads so query counts are clean.
   def setup
@@ -656,6 +657,25 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
     assert author.comments.include?(comment)
   end
 
+  def test_has_many_through_polymorphic_with_primary_key_option
+    assert_equal [categories(:general)], authors(:david).essay_categories
+
+    authors = Author.joins(:essay_categories).where('categories.id' => categories(:general).id)
+    assert_equal authors(:david), authors.first
+
+    assert_equal [owners(:blackbeard)], authors(:david).essay_owners
+
+    authors = Author.joins(:essay_owners).where("owners.name = 'blackbeard'")
+    assert_equal authors(:david), authors.first
+  end
+
+  def test_has_many_through_with_primary_key_option
+    assert_equal [categories(:general)], authors(:david).essay_categories_2
+
+    authors = Author.joins(:essay_categories_2).where('categories.id' => categories(:general).id)
+    assert_equal authors(:david), authors.first
+  end
+
   def test_size_of_through_association_should_increase_correctly_when_has_many_association_is_added
     post = posts(:thinking)
     readers = post.readers.size
@@ -679,10 +699,10 @@ class HasManyThroughAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_joining_has_many_through_belongs_to
-    posts = Post.joins(:author_categorizations).
+    posts = Post.joins(:author_categorizations).order('posts.id').
                  where('categorizations.id' => categorizations(:mary_thinking_sti).id)
 
-    assert_equal [posts(:eager_other)], posts
+    assert_equal [posts(:eager_other), posts(:misc_by_mary), posts(:other_by_mary)], posts
   end
 
   def test_select_chosen_fields_only
diff --git a/activerecord/test/cases/associations/has_one_through_associations_test.rb b/activerecord/test/cases/associations/has_one_through_associations_test.rb
index bfc5ddc747..9ba5549277 100644
--- a/activerecord/test/cases/associations/has_one_through_associations_test.rb
+++ b/activerecord/test/cases/associations/has_one_through_associations_test.rb
@@ -9,13 +9,16 @@ require 'models/member_detail'
 require 'models/minivan'
 require 'models/dashboard'
 require 'models/speedometer'
+require 'models/category'
 require 'models/author'
+require 'models/essay'
+require 'models/owner'
 require 'models/post'
 require 'models/comment'
 
 class HasOneThroughAssociationsTest < ActiveRecord::TestCase
   fixtures :member_types, :members, :clubs, :memberships, :sponsors, :organizations, :minivans,
-           :dashboards, :speedometers, :authors, :posts, :comments
+           :dashboards, :speedometers, :authors, :posts, :comments, :categories, :essays, :owners
 
   def setup
     @member = members(:groucho)
@@ -242,6 +245,25 @@ class HasOneThroughAssociationsTest < ActiveRecord::TestCase
     end
   end
 
+  def test_has_one_through_polymorphic_with_primary_key_option
+    assert_equal categories(:general), authors(:david).essay_category
+
+    authors = Author.joins(:essay_category).where('categories.id' => categories(:general).id)
+    assert_equal authors(:david), authors.first
+
+    assert_equal owners(:blackbeard), authors(:david).essay_owner
+
+    authors = Author.joins(:essay_owner).where("owners.name = 'blackbeard'")
+    assert_equal authors(:david), authors.first
+  end
+
+  def test_has_one_through_with_primary_key_option
+    assert_equal categories(:general), authors(:david).essay_category_2
+
+    authors = Author.joins(:essay_category_2).where('categories.id' => categories(:general).id)
+    assert_equal authors(:david), authors.first
+  end
+
   def test_has_one_through_with_default_scope_on_join_model
     assert_equal posts(:welcome).comments.order('id').first, authors(:david).comment_on_first_post
   end
diff --git a/activerecord/test/cases/associations/join_model_test.rb b/activerecord/test/cases/associations/join_model_test.rb
index 19303fef9f..1f95b31497 100644
--- a/activerecord/test/cases/associations/join_model_test.rb
+++ b/activerecord/test/cases/associations/join_model_test.rb
@@ -2,6 +2,7 @@ require "cases/helper"
 require 'models/tag'
 require 'models/tagging'
 require 'models/post'
+require 'models/rating'
 require 'models/item'
 require 'models/comment'
 require 'models/author'
@@ -288,7 +289,7 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase
   end
 
   def test_has_many_going_through_join_model_with_custom_foreign_key
-    assert_equal [], posts(:thinking).authors
+    assert_equal [authors(:bob)], posts(:thinking).authors
     assert_equal [authors(:mary)], posts(:authorless).authors
   end
 
@@ -305,7 +306,7 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase
   end
 
   def test_has_many_through_with_custom_primary_key_on_has_many_source
-    assert_equal [authors(:david)], posts(:thinking).authors_using_custom_pk
+    assert_equal [authors(:david), authors(:bob)], posts(:thinking).authors_using_custom_pk.order('authors.id')
   end
 
   def test_both_scoped_and_explicit_joins_should_be_respected
@@ -399,14 +400,6 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase
     end
   end
 
-  def test_has_many_through_has_many_through
-    assert_raise(ActiveRecord::HasManyThroughSourceAssociationMacroError) { authors(:david).tags }
-  end
-
-  def test_has_many_through_habtm
-    assert_raise(ActiveRecord::HasManyThroughSourceAssociationMacroError) { authors(:david).post_categories }
-  end
-
   def test_eager_load_has_many_through_has_many
     author = Author.find :first, :conditions => ['name = ?', 'David'], :include => :comments, :order => 'comments.id'
     SpecialComment.new; VerySpecialComment.new
diff --git a/activerecord/test/cases/associations/nested_through_associations_test.rb b/activerecord/test/cases/associations/nested_through_associations_test.rb
new file mode 100644
index 0000000000..dd450a2a8e
--- /dev/null
+++ b/activerecord/test/cases/associations/nested_through_associations_test.rb
@@ -0,0 +1,546 @@
+require "cases/helper"
+require 'models/author'
+require 'models/post'
+require 'models/person'
+require 'models/reference'
+require 'models/job'
+require 'models/reader'
+require 'models/comment'
+require 'models/tag'
+require 'models/tagging'
+require 'models/subscriber'
+require 'models/book'
+require 'models/subscription'
+require 'models/rating'
+require 'models/member'
+require 'models/member_detail'
+require 'models/member_type'
+require 'models/sponsor'
+require 'models/club'
+require 'models/organization'
+require 'models/category'
+require 'models/categorization'
+require 'models/membership'
+require 'models/essay'
+
+class NestedThroughAssociationsTest < ActiveRecord::TestCase
+  fixtures :authors, :books, :posts, :subscriptions, :subscribers, :tags, :taggings,
+           :people, :readers, :references, :jobs, :ratings, :comments, :members, :member_details,
+           :member_types, :sponsors, :clubs, :organizations, :categories, :categories_posts,
+           :categorizations, :memberships, :essays
+
+  # Through associations can either use the has_many or has_one macros.
+  #
+  # has_many
+  #   - Source reflection can be has_many, has_one, belongs_to or has_and_belongs_to_many
+  #   - Through reflection can be has_many, has_one, belongs_to or has_and_belongs_to_many
+  #
+  # has_one
+  #   - Source reflection can be has_one or belongs_to
+  #   - Through reflection can be has_one or belongs_to
+  #
+  # Additionally, the source reflection and/or through reflection may be subject to
+  # polymorphism and/or STI.
+  #
+  # When testing these, we need to make sure it works via loading the association directly, or
+  # joining the association, or including the association. We also need to ensure that associations
+  # are readonly where relevant.
+
+  # has_many through
+  # Source: has_many through
+  # Through: has_many
+  def test_has_many_through_has_many_with_has_many_through_source_reflection
+    general = tags(:general)
+    assert_equal [general, general], authors(:david).tags
+  end
+
+  def test_has_many_through_has_many_with_has_many_through_source_reflection_preload
+    authors = assert_queries(5) { Author.includes(:tags).to_a }
+    general = tags(:general)
+
+    assert_no_queries do
+      assert_equal [general, general], authors.first.tags
+    end
+  end
+
+  def test_has_many_through_has_many_with_has_many_through_source_reflection_preload_via_joins
+    assert_includes_and_joins_equal(
+      Author.where('tags.id' => tags(:general).id),
+      [authors(:david)], :tags
+    )
+
+    # This ensures that the polymorphism of taggings is being observed correctly
+    authors = Author.joins(:tags).where('taggings.taggable_type' => 'FakeModel')
+    assert authors.empty?
+  end
+
+  # has_many through
+  # Source: has_many
+  # Through: has_many through
+  def test_has_many_through_has_many_through_with_has_many_source_reflection
+    luke, david = subscribers(:first), subscribers(:second)
+    assert_equal [luke, david, david], authors(:david).subscribers.order('subscribers.nick')
+  end
+
+  def test_has_many_through_has_many_through_with_has_many_source_reflection_preload
+    luke, david = subscribers(:first), subscribers(:second)
+    authors = assert_queries(4) { Author.includes(:subscribers).to_a }
+    assert_no_queries do
+      assert_equal [luke, david, david], authors.first.subscribers.sort_by(&:nick)
+    end
+  end
+
+  def test_has_many_through_has_many_through_with_has_many_source_reflection_preload_via_joins
+    # All authors with subscribers where one of the subscribers' nick is 'alterself'
+    assert_includes_and_joins_equal(
+      Author.where('subscribers.nick' => 'alterself'),
+      [authors(:david)], :subscribers
+    )
+  end
+
+  # has_many through
+  # Source: has_one through
+  # Through: has_one
+  def test_has_many_through_has_one_with_has_one_through_source_reflection
+    assert_equal [member_types(:founding)], members(:groucho).nested_member_types
+  end
+
+  def test_has_many_through_has_one_with_has_one_through_source_reflection_preload
+    members = assert_queries(4) { Member.includes(:nested_member_types).to_a }
+    founding = member_types(:founding)
+    assert_no_queries do
+      assert_equal [founding], members.first.nested_member_types
+    end
+  end
+
+  def test_has_many_through_has_one_with_has_one_through_source_reflection_preload_via_joins
+    assert_includes_and_joins_equal(
+      Member.where('member_types.id' => member_types(:founding).id),
+      [members(:groucho)], :nested_member_types
+    )
+  end
+
+  # has_many through
+  # Source: has_one
+  # Through: has_one through
+  def test_has_many_through_has_one_through_with_has_one_source_reflection
+    assert_equal [sponsors(:moustache_club_sponsor_for_groucho)], members(:groucho).nested_sponsors
+  end
+
+  def test_has_many_through_has_one_through_with_has_one_source_reflection_preload
+    members = assert_queries(4) { Member.includes(:nested_sponsors).to_a }
+    mustache = sponsors(:moustache_club_sponsor_for_groucho)
+    assert_no_queries do
+      assert_equal [mustache], members.first.nested_sponsors
+    end
+  end
+
+  def test_has_many_through_has_one_through_with_has_one_source_reflection_preload_via_joins
+    assert_includes_and_joins_equal(
+      Member.where('sponsors.id' => sponsors(:moustache_club_sponsor_for_groucho).id),
+      [members(:groucho)], :nested_sponsors
+    )
+  end
+
+  # has_many through
+  # Source: has_many through
+  # Through: has_one
+  def test_has_many_through_has_one_with_has_many_through_source_reflection
+    groucho_details, other_details = member_details(:groucho), member_details(:some_other_guy)
+
+    assert_equal [groucho_details, other_details],
+                 members(:groucho).organization_member_details.order('member_details.id')
+  end
+
+  def test_has_many_through_has_one_with_has_many_through_source_reflection_preload
+    members = assert_queries(4) { Member.includes(:organization_member_details).to_a.sort_by(&:id) }
+    groucho_details, other_details = member_details(:groucho), member_details(:some_other_guy)
+
+    assert_no_queries do
+      assert_equal [groucho_details, other_details], members.first.organization_member_details.sort_by(&:id)
+    end
+  end
+
+  def test_has_many_through_has_one_with_has_many_through_source_reflection_preload_via_joins
+    assert_includes_and_joins_equal(
+      Member.where('member_details.id' => member_details(:groucho).id).order('member_details.id'),
+      [members(:groucho), members(:some_other_guy)], :organization_member_details
+    )
+
+    members = Member.joins(:organization_member_details).
+                     where('member_details.id' => 9)
+    assert members.empty?
+  end
+
+  # has_many through
+  # Source: has_many
+  # Through: has_one through
+  def test_has_many_through_has_one_through_with_has_many_source_reflection
+    groucho_details, other_details = member_details(:groucho), member_details(:some_other_guy)
+
+    assert_equal [groucho_details, other_details],
+                 members(:groucho).organization_member_details_2.order('member_details.id')
+  end
+
+  def test_has_many_through_has_one_through_with_has_many_source_reflection_preload
+    members = assert_queries(4) { Member.includes(:organization_member_details_2).to_a.sort_by(&:id) }
+    groucho_details, other_details = member_details(:groucho), member_details(:some_other_guy)
+
+    assert_no_queries do
+      assert_equal [groucho_details, other_details], members.first.organization_member_details_2.sort_by(&:id)
+    end
+  end
+
+  def test_has_many_through_has_one_through_with_has_many_source_reflection_preload_via_joins
+    assert_includes_and_joins_equal(
+      Member.where('member_details.id' => member_details(:groucho).id).order('member_details.id'),
+      [members(:groucho), members(:some_other_guy)], :organization_member_details_2
+    )
+
+    members = Member.joins(:organization_member_details_2).
+                     where('member_details.id' => 9)
+    assert members.empty?
+  end
+
+  # has_many through
+  # Source: has_and_belongs_to_many
+  # Through: has_many
+  def test_has_many_through_has_many_with_has_and_belongs_to_many_source_reflection
+    general, cooking = categories(:general), categories(:cooking)
+
+    assert_equal [general, cooking], authors(:bob).post_categories.order('categories.id')
+  end
+
+  def test_has_many_through_has_many_with_has_and_belongs_to_many_source_reflection_preload
+    authors = assert_queries(3) { Author.includes(:post_categories).to_a.sort_by(&:id) }
+    general, cooking = categories(:general), categories(:cooking)
+
+    assert_no_queries do
+      assert_equal [general, cooking], authors[2].post_categories.sort_by(&:id)
+    end
+  end
+
+  def test_has_many_through_has_many_with_has_and_belongs_to_many_source_reflection_preload_via_joins
+    assert_includes_and_joins_equal(
+      Author.where('categories.id' => categories(:cooking).id),
+      [authors(:bob)], :post_categories
+    )
+  end
+
+  # has_many through
+  # Source: has_many
+  # Through: has_and_belongs_to_many
+  def test_has_many_through_has_and_belongs_to_many_with_has_many_source_reflection
+    greetings, more = comments(:greetings), comments(:more_greetings)
+
+    assert_equal [greetings, more], categories(:technology).post_comments.order('comments.id')
+  end
+
+  def test_has_many_through_has_and_belongs_to_many_with_has_many_source_reflection_preload
+    categories = assert_queries(3) { Category.includes(:post_comments).to_a.sort_by(&:id) }
+    greetings, more = comments(:greetings), comments(:more_greetings)
+
+    assert_no_queries do
+      assert_equal [greetings, more], categories[1].post_comments.sort_by(&:id)
+    end
+  end
+
+  def test_has_many_through_has_and_belongs_to_many_with_has_many_source_reflection_preload_via_joins
+    assert_includes_and_joins_equal(
+      Category.where('comments.id' => comments(:more_greetings).id).order('comments.id'),
+      [categories(:general), categories(:technology)], :post_comments
+    )
+  end
+
+  # has_many through
+  # Source: has_many through a habtm
+  # Through: has_many through
+  def test_has_many_through_has_many_with_has_many_through_habtm_source_reflection
+    greetings, more = comments(:greetings), comments(:more_greetings)
+
+    assert_equal [greetings, more], authors(:bob).category_post_comments.order('comments.id')
+  end
+
+  def test_has_many_through_has_many_with_has_many_through_habtm_source_reflection_preload
+    authors = assert_queries(5) { Author.includes(:category_post_comments).to_a.sort_by(&:id) }
+    greetings, more = comments(:greetings), comments(:more_greetings)
+
+    assert_no_queries do
+      assert_equal [greetings, more], authors[2].category_post_comments.sort_by(&:id)
+    end
+  end
+
+  def test_has_many_through_has_many_with_has_many_through_habtm_source_reflection_preload_via_joins
+    assert_includes_and_joins_equal(
+      Author.where('comments.id' => comments(:does_it_hurt).id).order('authors.id'),
+      [authors(:david), authors(:mary)], :category_post_comments
+    )
+  end
+
+  # has_many through
+  # Source: belongs_to
+  # Through: has_many through
+  def test_has_many_through_has_many_through_with_belongs_to_source_reflection
+    assert_equal [tags(:general), tags(:general)], authors(:david).tagging_tags
+  end
+
+  def test_has_many_through_has_many_through_with_belongs_to_source_reflection_preload
+    authors = assert_queries(5) { Author.includes(:tagging_tags).to_a }
+    general = tags(:general)
+
+    assert_no_queries do
+      assert_equal [general, general], authors.first.tagging_tags
+    end
+  end
+
+  def test_has_many_through_has_many_through_with_belongs_to_source_reflection_preload_via_joins
+    assert_includes_and_joins_equal(
+      Author.where('tags.id' => tags(:general).id),
+      [authors(:david)], :tagging_tags
+    )
+  end
+
+  # has_many through
+  # Source: has_many through
+  # Through: belongs_to
+  def test_has_many_through_belongs_to_with_has_many_through_source_reflection
+    welcome_general, thinking_general = taggings(:welcome_general), taggings(:thinking_general)
+
+    assert_equal [welcome_general, thinking_general],
+                 categorizations(:david_welcome_general).post_taggings.order('taggings.id')
+  end
+
+  def test_has_many_through_belongs_to_with_has_many_through_source_reflection_preload
+    categorizations = assert_queries(4) { Categorization.includes(:post_taggings).to_a.sort_by(&:id) }
+    welcome_general, thinking_general = taggings(:welcome_general), taggings(:thinking_general)
+
+    assert_no_queries do
+      assert_equal [welcome_general, thinking_general], categorizations.first.post_taggings.sort_by(&:id)
+    end
+  end
+
+  def test_has_many_through_belongs_to_with_has_many_through_source_reflection_preload_via_joins
+    assert_includes_and_joins_equal(
+      Categorization.where('taggings.id' => taggings(:welcome_general).id).order('taggings.id'),
+      [categorizations(:david_welcome_general)], :post_taggings
+    )
+  end
+
+  # has_one through
+  # Source: has_one through
+  # Through: has_one
+  def test_has_one_through_has_one_with_has_one_through_source_reflection
+    assert_equal member_types(:founding), members(:groucho).nested_member_type
+  end
+
+  def test_has_one_through_has_one_with_has_one_through_source_reflection_preload
+    members = assert_queries(4) { Member.includes(:nested_member_type).to_a.sort_by(&:id) }
+    founding = member_types(:founding)
+
+    assert_no_queries do
+      assert_equal founding, members.first.nested_member_type
+    end
+  end
+
+  def test_has_one_through_has_one_with_has_one_through_source_reflection_preload_via_joins
+    assert_includes_and_joins_equal(
+      Member.where('member_types.id' => member_types(:founding).id),
+      [members(:groucho)], :nested_member_type
+    )
+  end
+
+  # has_one through
+  # Source: belongs_to
+  # Through: has_one through
+  def test_has_one_through_has_one_through_with_belongs_to_source_reflection
+    assert_equal categories(:general), members(:groucho).club_category
+  end
+
+  def test_has_one_through_has_one_through_with_belongs_to_source_reflection_preload
+    members = assert_queries(4) { Member.includes(:club_category).to_a.sort_by(&:id) }
+    general = categories(:general)
+
+    assert_no_queries do
+      assert_equal general, members.first.club_category
+    end
+  end
+
+  def test_has_one_through_has_one_through_with_belongs_to_source_reflection_preload_via_joins
+    assert_includes_and_joins_equal(
+      Member.where('categories.id' => categories(:technology).id),
+      [members(:blarpy_winkup)], :club_category
+    )
+  end
+
+  def test_distinct_has_many_through_a_has_many_through_association_on_source_reflection
+    author = authors(:david)
+    assert_equal [tags(:general)], author.distinct_tags
+  end
+
+  def test_distinct_has_many_through_a_has_many_through_association_on_through_reflection
+    author = authors(:david)
+    assert_equal [subscribers(:first), subscribers(:second)],
+                 author.distinct_subscribers.order('subscribers.nick')
+  end
+
+  def test_nested_has_many_through_with_a_table_referenced_multiple_times
+    author = authors(:bob)
+    assert_equal [posts(:misc_by_bob), posts(:misc_by_mary), posts(:other_by_bob), posts(:other_by_mary)],
+                 author.similar_posts.sort_by(&:id)
+
+    # Mary and Bob both have posts in misc, but they are the only ones.
+    authors = Author.joins(:similar_posts).where('posts.id' => posts(:misc_by_bob).id)
+    assert_equal [authors(:mary), authors(:bob)], authors.uniq.sort_by(&:id)
+
+    # Check the polymorphism of taggings is being observed correctly (in both joins)
+    authors = Author.joins(:similar_posts).where('taggings.taggable_type' => 'FakeModel')
+    assert authors.empty?
+    authors = Author.joins(:similar_posts).where('taggings_authors_join.taggable_type' => 'FakeModel')
+    assert authors.empty?
+  end
+
+  def test_has_many_through_with_foreign_key_option_on_through_reflection
+    assert_equal [posts(:welcome), posts(:authorless)], people(:david).agents_posts.order('posts.id')
+    assert_equal [authors(:david)], references(:david_unicyclist).agents_posts_authors
+
+    references = Reference.joins(:agents_posts_authors).where('authors.id' => authors(:david).id)
+    assert_equal [references(:david_unicyclist)], references
+  end
+
+  def test_has_many_through_with_foreign_key_option_on_source_reflection
+    assert_equal [people(:michael), people(:susan)], jobs(:unicyclist).agents.order('people.id')
+
+    jobs = Job.joins(:agents)
+    assert_equal [jobs(:unicyclist), jobs(:unicyclist)], jobs
+  end
+
+  def test_has_many_through_with_sti_on_through_reflection
+    ratings = posts(:sti_comments).special_comments_ratings.sort_by(&:id)
+    assert_equal [ratings(:special_comment_rating), ratings(:sub_special_comment_rating)], ratings
+
+    # Ensure STI is respected in the join
+    scope = Post.joins(:special_comments_ratings).where(:id => posts(:sti_comments).id)
+    assert scope.where("comments.type" => "Comment").empty?
+    assert !scope.where("comments.type" => "SpecialComment").empty?
+    assert !scope.where("comments.type" => "SubSpecialComment").empty?
+  end
+
+  def test_has_many_through_with_sti_on_nested_through_reflection
+    taggings = posts(:sti_comments).special_comments_ratings_taggings
+    assert_equal [taggings(:special_comment_rating)], taggings
+
+    scope = Post.joins(:special_comments_ratings_taggings).where(:id => posts(:sti_comments).id)
+    assert scope.where("comments.type" => "Comment").empty?
+    assert !scope.where("comments.type" => "SpecialComment").empty?
+  end
+
+  def test_nested_has_many_through_writers_should_raise_error
+    david = authors(:david)
+    subscriber = subscribers(:first)
+
+    assert_raises(ActiveRecord::HasManyThroughNestedAssociationsAreReadonly) do
+      david.subscribers = [subscriber]
+    end
+
+    assert_raises(ActiveRecord::HasManyThroughNestedAssociationsAreReadonly) do
+      david.subscriber_ids = [subscriber.id]
+    end
+
+    assert_raises(ActiveRecord::HasManyThroughNestedAssociationsAreReadonly) do
+      david.subscribers << subscriber
+    end
+
+    assert_raises(ActiveRecord::HasManyThroughNestedAssociationsAreReadonly) do
+      david.subscribers.delete(subscriber)
+    end
+
+    assert_raises(ActiveRecord::HasManyThroughNestedAssociationsAreReadonly) do
+      david.subscribers.clear
+    end
+
+    assert_raises(ActiveRecord::HasManyThroughNestedAssociationsAreReadonly) do
+      david.subscribers.build
+    end
+
+    assert_raises(ActiveRecord::HasManyThroughNestedAssociationsAreReadonly) do
+      david.subscribers.create
+    end
+  end
+
+  def test_nested_has_one_through_writers_should_raise_error
+    groucho = members(:groucho)
+    founding = member_types(:founding)
+
+    assert_raises(ActiveRecord::HasManyThroughNestedAssociationsAreReadonly) do
+      groucho.nested_member_type = founding
+    end
+  end
+
+  def test_nested_has_many_through_with_conditions_on_through_associations
+    assert_equal [tags(:blue)], authors(:bob).misc_post_first_blue_tags
+  end
+
+  def test_nested_has_many_through_with_conditions_on_through_associations_preload
+    assert Author.where('tags.id' => 100).joins(:misc_post_first_blue_tags).empty?
+
+    authors = assert_queries(3) { Author.includes(:misc_post_first_blue_tags).to_a.sort_by(&:id) }
+    blue = tags(:blue)
+
+    assert_no_queries do
+      assert_equal [blue], authors[2].misc_post_first_blue_tags
+    end
+  end
+
+  def test_nested_has_many_through_with_conditions_on_through_associations_preload_via_joins
+    # Pointless condition to force single-query loading
+    assert_includes_and_joins_equal(
+      Author.where('tags.id = tags.id'),
+      [authors(:bob)], :misc_post_first_blue_tags
+    )
+  end
+
+  def test_nested_has_many_through_with_conditions_on_source_associations
+    assert_equal [tags(:blue)], authors(:bob).misc_post_first_blue_tags_2
+  end
+
+  def test_nested_has_many_through_with_conditions_on_source_associations_preload
+    authors = assert_queries(4) { Author.includes(:misc_post_first_blue_tags_2).to_a.sort_by(&:id) }
+    blue = tags(:blue)
+
+    assert_no_queries do
+      assert_equal [blue], authors[2].misc_post_first_blue_tags_2
+    end
+  end
+
+  def test_nested_has_many_through_with_conditions_on_source_associations_preload_via_joins
+    # Pointless condition to force single-query loading
+    assert_includes_and_joins_equal(
+      Author.where('tags.id = tags.id'),
+      [authors(:bob)], :misc_post_first_blue_tags_2
+    )
+  end
+
+  def test_nested_has_many_through_with_foreign_key_option_on_the_source_reflection_through_reflection
+    assert_equal [categories(:general)], organizations(:nsa).author_essay_categories
+
+    organizations = Organization.joins(:author_essay_categories).
+                                 where('categories.id' => categories(:general).id)
+    assert_equal [organizations(:nsa)], organizations
+
+    assert_equal categories(:general), organizations(:nsa).author_owned_essay_category
+
+    organizations = Organization.joins(:author_owned_essay_category).
+                                 where('categories.id' => categories(:general).id)
+    assert_equal [organizations(:nsa)], organizations
+  end
+
+  private
+
+    def assert_includes_and_joins_equal(query, expected, association)
+      actual = assert_queries(1) { query.joins(association).to_a.uniq }
+      assert_equal expected, actual
+
+      actual = assert_queries(1) { query.includes(association).to_a.uniq }
+      assert_equal expected, actual
+    end
+end
diff --git a/activerecord/test/cases/attribute_methods_test.rb b/activerecord/test/cases/attribute_methods_test.rb
index dfacf58da8..d03c3ee1a1 100644
--- a/activerecord/test/cases/attribute_methods_test.rb
+++ b/activerecord/test/cases/attribute_methods_test.rb
@@ -118,22 +118,18 @@ class AttributeMethodsTest < ActiveRecord::TestCase
   end
 
   def test_read_attributes_before_type_cast_on_datetime
-    developer = Developer.find(:first)
-    if current_adapter?(:Mysql2Adapter, :OracleAdapter)
-      # Mysql2 and Oracle adapters keep the value in Time instance
-      assert_equal developer.created_at.to_s(:db), developer.attributes_before_type_cast["created_at"].to_s(:db)
-    else
-      assert_equal developer.created_at.to_s(:db), developer.attributes_before_type_cast["created_at"].to_s
-    end
-
-    developer.created_at = "345643456"
+    in_time_zone "Pacific Time (US & Canada)" do
+      record = @target.new
 
-    assert_equal developer.created_at_before_type_cast, "345643456"
-    assert_equal developer.created_at, nil
+      record.written_on = "345643456"
+      assert_equal "345643456", record.written_on_before_type_cast
+      assert_equal nil, record.written_on
 
-    developer.created_at = "2010-03-21 21:23:32"
-    assert_equal developer.created_at_before_type_cast, "2010-03-21 21:23:32"
-    assert_equal developer.created_at, Time.parse("2010-03-21 21:23:32")
+      record.written_on = "2009-10-11 12:13:14"
+      assert_equal "2009-10-11 12:13:14", record.written_on_before_type_cast
+      assert_equal Time.zone.parse("2009-10-11 12:13:14"), record.written_on
+      assert_equal ActiveSupport::TimeZone["Pacific Time (US & Canada)"], record.written_on.time_zone
+    end
   end
 
   def test_hash_content
diff --git a/activerecord/test/cases/base_test.rb b/activerecord/test/cases/base_test.rb
index d03fc68a11..fba7af741d 100644
--- a/activerecord/test/cases/base_test.rb
+++ b/activerecord/test/cases/base_test.rb
@@ -45,6 +45,8 @@ class ReadonlyTitlePost < Post
   attr_readonly :title
 end
 
+class Weird < ActiveRecord::Base; end
+
 class Boolean < ActiveRecord::Base; end
 
 class BasicsTest < ActiveRecord::TestCase
@@ -477,6 +479,16 @@ class BasicsTest < ActiveRecord::TestCase
     assert_equal "changed", post.body
   end
 
+  def test_non_valid_identifier_column_name
+    weird = Weird.create('a$b' => 'value')
+    weird.reload
+    assert_equal 'value', weird.send('a$b')
+
+    weird.update_attribute('a$b', 'value2')
+    weird.reload
+    assert_equal 'value2', weird.send('a$b')
+  end
+
   def test_multiparameter_attributes_on_date
     attributes = { "last_read(1i)" => "2004", "last_read(2i)" => "6", "last_read(3i)" => "24" }
     topic = Topic.find(1)
diff --git a/activerecord/test/cases/batches_test.rb b/activerecord/test/cases/batches_test.rb
index 6f65fb96d1..dc0e0da4c5 100644
--- a/activerecord/test/cases/batches_test.rb
+++ b/activerecord/test/cases/batches_test.rb
@@ -25,7 +25,7 @@ class EachTest < ActiveRecord::TestCase
   end
 
   def test_each_should_execute_if_id_is_in_select
-    assert_queries(4) do
+    assert_queries(6) do
       Post.find_each(:select => "id, title, type", :batch_size => 2) do |post|
         assert_kind_of Post, post
       end
diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb
index c35590b84b..543981b4a0 100644
--- a/activerecord/test/cases/finder_test.rb
+++ b/activerecord/test/cases/finder_test.rb
@@ -124,11 +124,13 @@ class FinderTest < ActiveRecord::TestCase
   def test_find_all_with_limit_and_offset_and_multiple_order_clauses
     first_three_posts = Post.find :all, :order => 'author_id, id', :limit => 3, :offset => 0
     second_three_posts = Post.find :all, :order => ' author_id,id ', :limit => 3, :offset => 3
-    last_posts = Post.find :all, :order => ' author_id, id  ', :limit => 3, :offset => 6
+    third_three_posts = Post.find :all, :order => ' author_id, id  ', :limit => 3, :offset => 6
+    last_posts = Post.find :all, :order => ' author_id, id  ', :limit => 3, :offset => 9
 
     assert_equal [[0,3],[1,1],[1,2]], first_three_posts.map { |p| [p.author_id, p.id] }
     assert_equal [[1,4],[1,5],[1,6]], second_three_posts.map { |p| [p.author_id, p.id] }
-    assert_equal [[2,7]], last_posts.map { |p| [p.author_id, p.id] }
+    assert_equal [[2,7],[2,9],[2,11]], third_three_posts.map { |p| [p.author_id, p.id] }
+    assert_equal [[3,8],[3,10]], last_posts.map { |p| [p.author_id, p.id] }
   end
 
 
@@ -189,6 +191,30 @@ class FinderTest < ActiveRecord::TestCase
     assert_nil Topic.where("title = 'The Second Topic of the day!'").first
   end
 
+  def test_first_bang_present
+    assert_nothing_raised do
+      assert_equal topics(:second), Topic.where("title = 'The Second Topic of the day'").first!
+    end
+  end
+
+  def test_first_bang_missing
+    assert_raises ActiveRecord::RecordNotFound do
+      Topic.where("title = 'This title does not exist'").first!
+    end
+  end
+
+  def test_last_bang_present
+    assert_nothing_raised do
+      assert_equal topics(:second), Topic.where("title = 'The Second Topic of the day'").last!
+    end
+  end
+
+  def test_last_bang_missing
+    assert_raises ActiveRecord::RecordNotFound do
+      Topic.where("title = 'This title does not exist'").last!
+    end
+  end
+
   def test_unexisting_record_exception_handling
     assert_raise(ActiveRecord::RecordNotFound) {
       Topic.find(1).parent
diff --git a/activerecord/test/cases/habtm_destroy_order_test.rb b/activerecord/test/cases/habtm_destroy_order_test.rb
index 15598392e2..f2b91d977e 100644
--- a/activerecord/test/cases/habtm_destroy_order_test.rb
+++ b/activerecord/test/cases/habtm_destroy_order_test.rb
@@ -13,5 +13,39 @@ class HabtmDestroyOrderTest < ActiveRecord::TestCase
         sicp.destroy
       end
     end
+    assert !sicp.destroyed?
+  end
+
+  test "not destroying a student with lessons leaves student<=>lesson association intact" do
+    # test a normal before_destroy doesn't destroy the habtm joins
+    begin
+      sicp = Lesson.new(:name => "SICP")
+      ben = Student.new(:name => "Ben Bitdiddle")
+      # add a before destroy to student
+      Student.class_eval do
+        before_destroy do
+          raise ActiveRecord::Rollback unless lessons.empty?
+        end
+      end
+      ben.lessons << sicp
+      ben.save!
+      ben.destroy
+      assert !ben.reload.lessons.empty?
+    ensure
+      # get rid of it so Student is still like it was
+      Student.reset_callbacks(:destroy)
+    end
+  end
+
+  test "not destroying a lesson with students leaves student<=>lesson association intact" do
+    # test a more aggressive before_destroy  doesn't destroy the habtm joins and still throws the exception
+    sicp = Lesson.new(:name => "SICP")
+    ben = Student.new(:name => "Ben Bitdiddle")
+    sicp.students << ben
+    sicp.save!
+    assert_raises LessonError do
+      sicp.destroy
+    end
+    assert !sicp.reload.students.empty?
   end
 end
diff --git a/activerecord/test/cases/identity_map_test.rb b/activerecord/test/cases/identity_map_test.rb
index 399d6c26df..89f7b92d09 100644
--- a/activerecord/test/cases/identity_map_test.rb
+++ b/activerecord/test/cases/identity_map_test.rb
@@ -207,31 +207,31 @@ class IdentityMapTest < ActiveRecord::TestCase
 
   def test_find_with_preloaded_associations
     assert_queries(2) do
-      posts = Post.preload(:comments)
+      posts = Post.preload(:comments).order('posts.id')
       assert posts.first.comments.first
     end
 
     # With IM we'll retrieve post object from previous query, it'll have comments
     # already preloaded from first call
     assert_queries(1) do
-      posts = Post.preload(:comments).to_a
+      posts = Post.preload(:comments).order('posts.id')
       assert posts.first.comments.first
     end
 
     assert_queries(2) do
-      posts = Post.preload(:author)
+      posts = Post.preload(:author).order('posts.id')
       assert posts.first.author
     end
 
     # With IM we'll retrieve post object from previous query, it'll have comments
     # already preloaded from first call
     assert_queries(1) do
-      posts = Post.preload(:author).to_a
+      posts = Post.preload(:author).order('posts.id')
       assert posts.first.author
     end
 
     assert_queries(1) do
-      posts = Post.preload(:author, :comments).to_a
+      posts = Post.preload(:author, :comments).order('posts.id')
       assert posts.first.author
       assert posts.first.comments.first
     end
@@ -239,22 +239,22 @@ class IdentityMapTest < ActiveRecord::TestCase
 
   def test_find_with_included_associations
     assert_queries(2) do
-      posts = Post.includes(:comments)
+      posts = Post.includes(:comments).order('posts.id')
       assert posts.first.comments.first
     end
 
     assert_queries(1) do
-      posts = Post.scoped.includes(:comments)
+      posts = Post.scoped.includes(:comments).order('posts.id')
       assert posts.first.comments.first
     end
 
     assert_queries(2) do
-      posts = Post.includes(:author)
+      posts = Post.includes(:author).order('posts.id')
       assert posts.first.author
     end
 
     assert_queries(1) do
-      posts = Post.includes(:author, :comments).to_a
+      posts = Post.includes(:author, :comments).order('posts.id')
       assert posts.first.author
       assert posts.first.comments.first
     end
diff --git a/activerecord/test/cases/json_serialization_test.rb b/activerecord/test/cases/json_serialization_test.rb
index 5da7f9e1b9..8664d63e8f 100644
--- a/activerecord/test/cases/json_serialization_test.rb
+++ b/activerecord/test/cases/json_serialization_test.rb
@@ -181,7 +181,11 @@ class DatabaseConnectedJsonEncodingTest < ActiveRecord::TestCase
   def test_should_allow_except_option_for_list_of_authors
     ActiveRecord::Base.include_root_in_json = false
     authors = [@david, @mary]
-    assert_equal %([{"id":1},{"id":2}]), ActiveSupport::JSON.encode(authors, :except => [:name, :author_address_id, :author_address_extra_id])
+    encoded = ActiveSupport::JSON.encode(authors, :except => [
+      :name, :author_address_id, :author_address_extra_id,
+      :organization_id, :owned_essay_id
+    ])
+    assert_equal %([{"id":1},{"id":2}]), encoded
   ensure
     ActiveRecord::Base.include_root_in_json = true
   end
@@ -196,7 +200,7 @@ class DatabaseConnectedJsonEncodingTest < ActiveRecord::TestCase
     )
 
     ['"name":"David"', '"posts":[', '{"id":1}', '{"id":2}', '{"id":4}',
-     '{"id":5}', '{"id":6}', '"name":"Mary"', '"posts":[{"id":7}]'].each do |fragment|
+     '{"id":5}', '{"id":6}', '"name":"Mary"', '"posts":[', '{"id":7}', '{"id":9}'].each do |fragment|
       assert json.include?(fragment), json
      end
   end
diff --git a/activerecord/test/cases/reflection_test.rb b/activerecord/test/cases/reflection_test.rb
index eb580928ba..97d9669483 100644
--- a/activerecord/test/cases/reflection_test.rb
+++ b/activerecord/test/cases/reflection_test.rb
@@ -7,9 +7,16 @@ require 'models/subscriber'
 require 'models/ship'
 require 'models/pirate'
 require 'models/price_estimate'
-require 'models/tagging'
+require 'models/essay'
 require 'models/author'
+require 'models/organization'
 require 'models/post'
+require 'models/tagging'
+require 'models/category'
+require 'models/book'
+require 'models/subscriber'
+require 'models/subscription'
+require 'models/tag'
 require 'models/sponsor'
 
 class ReflectionTest < ActiveRecord::TestCase
@@ -195,10 +202,54 @@ class ReflectionTest < ActiveRecord::TestCase
     assert_kind_of ThroughReflection, Subscriber.reflect_on_association(:books)
   end
 
+  def test_chain
+    expected = [
+      Organization.reflect_on_association(:author_essay_categories),
+      Author.reflect_on_association(:essays),
+      Organization.reflect_on_association(:authors)
+    ]
+    actual = Organization.reflect_on_association(:author_essay_categories).chain
+
+    assert_equal expected, actual
+  end
+
+  def test_conditions
+    expected = [
+      [{ :tags => { :name => 'Blue' } }],
+      [{ :taggings => { :comment => 'first' } }, { "taggable_type" => "Post" }],
+      [{ :posts => { :title => ['misc post by bob', 'misc post by mary'] } }]
+    ]
+    actual = Author.reflect_on_association(:misc_post_first_blue_tags).conditions
+    assert_equal expected, actual
+
+    expected = [
+      [{ :tags => { :name => 'Blue' } }, { :taggings => { :comment => 'first' } }, { :posts => { :title => ['misc post by bob', 'misc post by mary'] } }],
+      [{ "taggable_type" => "Post" }],
+      []
+    ]
+    actual = Author.reflect_on_association(:misc_post_first_blue_tags_2).conditions
+    assert_equal expected, actual
+  end
+
+  def test_nested?
+    assert !Author.reflect_on_association(:comments).nested?
+    assert Author.reflect_on_association(:tags).nested?
+
+    # Only goes :through once, but the through_reflection is a has_and_belongs_to_many, so this is
+    # a nested through association
+    assert Category.reflect_on_association(:post_comments).nested?
+  end
+
   def test_association_primary_key
-    assert_equal "id", Author.reflect_on_association(:posts).association_primary_key.to_s
+    # Normal association
+    assert_equal "id",   Author.reflect_on_association(:posts).association_primary_key.to_s
     assert_equal "name", Author.reflect_on_association(:essay).association_primary_key.to_s
-    assert_equal "id", Tagging.reflect_on_association(:taggable).association_primary_key.to_s
+    assert_equal "id",   Tagging.reflect_on_association(:taggable).association_primary_key.to_s
+
+    # Through association (uses the :primary_key option from the source reflection)
+    assert_equal "nick", Author.reflect_on_association(:subscribers).association_primary_key.to_s
+    assert_equal "name", Author.reflect_on_association(:essay_category).association_primary_key.to_s
+    assert_equal "custom_primary_key", Author.reflect_on_association(:tags_with_primary_key).association_primary_key.to_s # nested
   end
 
   def test_active_record_primary_key
diff --git a/activerecord/test/cases/relation_scoping_test.rb b/activerecord/test/cases/relation_scoping_test.rb
index cda2850b02..7369aaea1d 100644
--- a/activerecord/test/cases/relation_scoping_test.rb
+++ b/activerecord/test/cases/relation_scoping_test.rb
@@ -335,7 +335,7 @@ class DefaultScopingTest < ActiveRecord::TestCase
     end
 
     records = klass.all
-    assert_equal 1, records.length
+    assert_equal 3, records.length
     assert_equal 2, records.first.author_id
   end
 
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index 00b7c26080..4c5c871251 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -165,7 +165,7 @@ class RelationTest < ActiveRecord::TestCase
 
   def test_finding_with_complex_order
     tags = Tag.includes(:taggings).order("REPLACE('abc', taggings.taggable_type, taggings.taggable_type)").to_a
-    assert_equal 2, tags.length
+    assert_equal 3, tags.length
   end
 
   def test_finding_with_order_limit_and_offset
@@ -281,27 +281,27 @@ class RelationTest < ActiveRecord::TestCase
 
   def test_find_with_preloaded_associations
     assert_queries(2) do
-      posts = Post.preload(:comments)
+      posts = Post.preload(:comments).order('posts.id')
       assert posts.first.comments.first
     end
 
     assert_queries(ActiveRecord::IdentityMap.enabled? ? 1 : 2) do
-      posts = Post.preload(:comments).to_a
+      posts = Post.preload(:comments).order('posts.id')
       assert posts.first.comments.first
     end
 
     assert_queries(2) do
-      posts = Post.preload(:author)
+      posts = Post.preload(:author).order('posts.id')
       assert posts.first.author
     end
 
     assert_queries(ActiveRecord::IdentityMap.enabled? ? 1 : 2) do
-      posts = Post.preload(:author).to_a
+      posts = Post.preload(:author).order('posts.id')
       assert posts.first.author
     end
 
     assert_queries(ActiveRecord::IdentityMap.enabled? ? 1 : 3) do
-      posts = Post.preload(:author, :comments).to_a
+      posts = Post.preload(:author, :comments).order('posts.id')
       assert posts.first.author
       assert posts.first.comments.first
     end
@@ -309,22 +309,22 @@ class RelationTest < ActiveRecord::TestCase
 
   def test_find_with_included_associations
     assert_queries(2) do
-      posts = Post.includes(:comments)
+      posts = Post.includes(:comments).order('posts.id')
       assert posts.first.comments.first
     end
 
     assert_queries(ActiveRecord::IdentityMap.enabled? ? 1 : 2) do
-      posts = Post.scoped.includes(:comments)
+      posts = Post.scoped.includes(:comments).order('posts.id')
       assert posts.first.comments.first
     end
 
     assert_queries(2) do
-      posts = Post.includes(:author)
+      posts = Post.includes(:author).order('posts.id')
       assert posts.first.author
     end
 
     assert_queries(ActiveRecord::IdentityMap.enabled? ? 1 : 3) do
-      posts = Post.includes(:author, :comments).to_a
+      posts = Post.includes(:author, :comments).order('posts.id')
       assert posts.first.author
       assert posts.first.comments.first
     end
@@ -538,7 +538,7 @@ class RelationTest < ActiveRecord::TestCase
 
   def test_last
     authors = Author.scoped
-    assert_equal authors(:mary), authors.last
+    assert_equal authors(:bob), authors.last
   end
 
   def test_destroy_all
@@ -618,22 +618,22 @@ class RelationTest < ActiveRecord::TestCase
   def test_count
     posts = Post.scoped
 
-    assert_equal 7, posts.count
-    assert_equal 7, posts.count(:all)
-    assert_equal 7, posts.count(:id)
+    assert_equal 11, posts.count
+    assert_equal 11, posts.count(:all)
+    assert_equal 11, posts.count(:id)
 
     assert_equal 1, posts.where('comments_count > 1').count
-    assert_equal 5, posts.where(:comments_count => 0).count
+    assert_equal 9, posts.where(:comments_count => 0).count
   end
 
   def test_count_with_distinct
     posts = Post.scoped
 
     assert_equal 3, posts.count(:comments_count, :distinct => true)
-    assert_equal 7, posts.count(:comments_count, :distinct => false)
+    assert_equal 11, posts.count(:comments_count, :distinct => false)
 
     assert_equal 3, posts.select(:comments_count).count(:distinct => true)
-    assert_equal 7, posts.select(:comments_count).count(:distinct => false)
+    assert_equal 11, posts.select(:comments_count).count(:distinct => false)
   end
 
   def test_count_explicit_columns
@@ -643,7 +643,7 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal [0], posts.select('comments_count').where('id is not null').group('id').order('id').count.values.uniq
     assert_equal 0, posts.where('id is not null').select('comments_count').count
 
-    assert_equal 7, posts.select('comments_count').count('id')
+    assert_equal 11, posts.select('comments_count').count('id')
     assert_equal 0, posts.select('comments_count').count
     assert_equal 0, posts.count(:comments_count)
     assert_equal 0, posts.count('comments_count')
@@ -658,12 +658,12 @@ class RelationTest < ActiveRecord::TestCase
   def test_size
     posts = Post.scoped
 
-    assert_queries(1) { assert_equal 7, posts.size }
+    assert_queries(1) { assert_equal 11, posts.size }
     assert ! posts.loaded?
 
     best_posts = posts.where(:comments_count => 0)
     best_posts.to_a # force load
-    assert_no_queries { assert_equal 5, best_posts.size }
+    assert_no_queries { assert_equal 9, best_posts.size }
   end
 
   def test_count_complex_chained_relations
@@ -797,6 +797,10 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal Post.all, all_posts.all
   end
 
+  def test_extensions_with_except
+    assert_equal 2, Topic.named_extension.order(:author_name).except(:order).two
+  end
+
   def test_only
     relation = Post.where(:author_id => 1).order('id ASC').limit(1)
     assert_equal [posts(:welcome)], relation.all
@@ -808,6 +812,10 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal Post.limit(1).all.first, all_posts.first
   end
 
+  def test_extensions_with_only
+    assert_equal 2, Topic.named_extension.order(:author_name).only(:order).two
+  end
+
   def test_anonymous_extension
     relation = Post.where(:author_id => 1).order('id ASC').extending do
       def author
diff --git a/activerecord/test/fixtures/authors.yml b/activerecord/test/fixtures/authors.yml
index de2ec7d38b..832236a486 100644
--- a/activerecord/test/fixtures/authors.yml
+++ b/activerecord/test/fixtures/authors.yml
@@ -3,7 +3,13 @@ david:
   name: David
   author_address_id: 1
   author_address_extra_id: 2
+  organization_id: No Such Agency
+  owned_essay_id: A Modest Proposal
 
 mary:
   id: 2
   name: Mary
+
+bob:
+  id: 3
+  name: Bob
diff --git a/activerecord/test/fixtures/books.yml b/activerecord/test/fixtures/books.yml
index 473663ff5b..fb48645456 100644
--- a/activerecord/test/fixtures/books.yml
+++ b/activerecord/test/fixtures/books.yml
@@ -1,7 +1,9 @@
 awdr:
+  author_id: 1
   id: 1
   name: "Agile Web Development with Rails"
 
 rfr:
+  author_id: 1
   id: 2
   name: "Ruby for Rails"
diff --git a/activerecord/test/fixtures/categories.yml b/activerecord/test/fixtures/categories.yml
index b0770a093d..3e75e733a6 100644
--- a/activerecord/test/fixtures/categories.yml
+++ b/activerecord/test/fixtures/categories.yml
@@ -12,3 +12,8 @@ sti_test:
   id: 3
   name: Special category
   type: SpecialCategory
+
+cooking:
+  id: 4
+  name: Cooking
+  type: Category
diff --git a/activerecord/test/fixtures/categories_posts.yml b/activerecord/test/fixtures/categories_posts.yml
index 9b67ab4fa4..c6f0d885f5 100644
--- a/activerecord/test/fixtures/categories_posts.yml
+++ b/activerecord/test/fixtures/categories_posts.yml
@@ -21,3 +21,11 @@ sti_test_sti_habtm:
 general_hello:
   category_id: 1
   post_id: 4
+
+general_misc_by_bob:
+  category_id: 1
+  post_id: 8
+
+cooking_misc_by_bob:
+  category_id: 4
+  post_id: 8
diff --git a/activerecord/test/fixtures/categorizations.yml b/activerecord/test/fixtures/categorizations.yml
index c5b6fc9a51..62e5bd111a 100644
--- a/activerecord/test/fixtures/categorizations.yml
+++ b/activerecord/test/fixtures/categorizations.yml
@@ -15,3 +15,9 @@ mary_thinking_general:
   author_id: 2
   post_id: 2
   category_id: 1
+
+bob_misc_by_bob_technology:
+  id: 4
+  author_id: 3
+  post_id: 8
+  category_id: 2
diff --git a/activerecord/test/fixtures/clubs.yml b/activerecord/test/fixtures/clubs.yml
index 1986d28229..82e439e8e5 100644
--- a/activerecord/test/fixtures/clubs.yml
+++ b/activerecord/test/fixtures/clubs.yml
@@ -1,6 +1,8 @@
 boring_club:
   name: Banana appreciation society
+  category_id: 1
 moustache_club:
   name: Moustache and Eyebrow Fancier Club
 crazy_club:
-  name: Skull and bones
\ No newline at end of file
+  name: Skull and bones
+  category_id: 2
diff --git a/activerecord/test/fixtures/essays.yml b/activerecord/test/fixtures/essays.yml
new file mode 100644
index 0000000000..9d15d82359
--- /dev/null
+++ b/activerecord/test/fixtures/essays.yml
@@ -0,0 +1,6 @@
+david_modest_proposal:
+  name: A Modest Proposal
+  writer_type: Author
+  writer_id: David
+  category_id: General
+  author_id: David
diff --git a/activerecord/test/fixtures/member_details.yml b/activerecord/test/fixtures/member_details.yml
new file mode 100644
index 0000000000..e1fe695a9b
--- /dev/null
+++ b/activerecord/test/fixtures/member_details.yml
@@ -0,0 +1,8 @@
+groucho:
+  id: 1
+  member_id: 1
+  organization: nsa
+some_other_guy:
+  id: 2
+  member_id: 2
+  organization: nsa
diff --git a/activerecord/test/fixtures/members.yml b/activerecord/test/fixtures/members.yml
index 824840b7e5..f3bbf0dac6 100644
--- a/activerecord/test/fixtures/members.yml
+++ b/activerecord/test/fixtures/members.yml
@@ -6,3 +6,6 @@ some_other_guy:
   id: 2
   name: Englebert Humperdink
   member_type_id: 2
+blarpy_winkup:
+  id: 3
+  name: Blarpy Winkup
diff --git a/activerecord/test/fixtures/memberships.yml b/activerecord/test/fixtures/memberships.yml
index eed8b22af8..60eb641054 100644
--- a/activerecord/test/fixtures/memberships.yml
+++ b/activerecord/test/fixtures/memberships.yml
@@ -18,3 +18,10 @@ other_guys_membership:
   member_id: 2
   favourite: false
   type: CurrentMembership
+
+blarpy_winkup_crazy_club:
+  joined_on: <%= 4.weeks.ago.to_s(:db) %>
+  club: crazy_club
+  member_id: 3
+  favourite: false
+  type: CurrentMembership
diff --git a/activerecord/test/fixtures/owners.yml b/activerecord/test/fixtures/owners.yml
index d5493a84b7..2d21ce433c 100644
--- a/activerecord/test/fixtures/owners.yml
+++ b/activerecord/test/fixtures/owners.yml
@@ -1,6 +1,7 @@
 blackbeard:
   owner_id: 1
   name: blackbeard
+  essay_id: A Modest Proposal
 
 ashley:
   owner_id: 2
diff --git a/activerecord/test/fixtures/posts.yml b/activerecord/test/fixtures/posts.yml
index 07069a064f..7298096025 100644
--- a/activerecord/test/fixtures/posts.yml
+++ b/activerecord/test/fixtures/posts.yml
@@ -52,3 +52,31 @@ eager_other:
   title: eager loading with OR'd conditions
   body: hello
   type: Post
+
+misc_by_bob:
+  id: 8
+  author_id: 3
+  title: misc post by bob
+  body: hello
+  type: Post
+
+misc_by_mary:
+  id: 9
+  author_id: 2
+  title: misc post by mary
+  body: hello
+  type: Post
+
+other_by_bob:
+  id: 10
+  author_id: 3
+  title: other post by bob
+  body: hello
+  type: Post
+
+other_by_mary:
+  id: 11
+  author_id: 2
+  title: other post by mary
+  body: hello
+  type: Post
diff --git a/activerecord/test/fixtures/ratings.yml b/activerecord/test/fixtures/ratings.yml
new file mode 100644
index 0000000000..34e208efa3
--- /dev/null
+++ b/activerecord/test/fixtures/ratings.yml
@@ -0,0 +1,14 @@
+normal_comment_rating:
+  id: 1
+  comment_id: 8
+  value: 1
+
+special_comment_rating:
+  id: 2
+  comment_id: 6
+  value: 1
+
+sub_special_comment_rating:
+  id: 3
+  comment_id: 12
+  value: 1
diff --git a/activerecord/test/fixtures/taggings.yml b/activerecord/test/fixtures/taggings.yml
index 3db6a4c079..d339c12b25 100644
--- a/activerecord/test/fixtures/taggings.yml
+++ b/activerecord/test/fixtures/taggings.yml
@@ -26,3 +26,53 @@ godfather:
 orphaned:
   id: 5
   tag_id: 1
+
+misc_post_by_bob:
+  id: 6
+  tag_id: 2
+  taggable_id: 8
+  taggable_type: Post
+
+misc_post_by_mary:
+  id: 7
+  tag_id: 2
+  taggable_id: 9
+  taggable_type: Post
+
+misc_by_bob_blue_first:
+  id: 8
+  tag_id: 3
+  taggable_id: 8
+  taggable_type: Post
+  comment: first
+
+misc_by_bob_blue_second:
+  id: 9
+  tag_id: 3
+  taggable_id: 8
+  taggable_type: Post
+  comment: second
+
+other_by_bob_blue:
+  id: 10
+  tag_id: 3
+  taggable_id: 10
+  taggable_type: Post
+  comment: first
+
+other_by_mary_blue:
+  id: 11
+  tag_id: 3
+  taggable_id: 11
+  taggable_type: Post
+  comment: first
+
+special_comment_rating:
+  id: 12
+  taggable_id: 2
+  taggable_type: Rating
+
+normal_comment_rating:
+  id: 13
+  taggable_id: 1
+  taggable_type: Rating
diff --git a/activerecord/test/fixtures/tags.yml b/activerecord/test/fixtures/tags.yml
index 7610fd38b9..d4b7c9a4d5 100644
--- a/activerecord/test/fixtures/tags.yml
+++ b/activerecord/test/fixtures/tags.yml
@@ -4,4 +4,8 @@ general:
 
 misc:
   id: 2
-  name: Misc
\ No newline at end of file
+  name: Misc
+
+blue:
+  id: 3
+  name: Blue
diff --git a/activerecord/test/models/author.rb b/activerecord/test/models/author.rb
index 83a6f5d926..e0cbc44265 100644
--- a/activerecord/test/models/author.rb
+++ b/activerecord/test/models/author.rb
@@ -94,16 +94,50 @@ class Author < ActiveRecord::Base
   has_many :author_favorites
   has_many :favorite_authors, :through => :author_favorites, :order => 'name'
 
-  has_many :tagging,  :through => :posts # through polymorphic has_one
-  has_many :taggings, :through => :posts, :source => :taggings # through polymorphic has_many
-  has_many :tags,     :through => :posts # through has_many :through
+  has_many :tagging,         :through => :posts
+  has_many :taggings,        :through => :posts
+  has_many :tags,            :through => :posts
+  has_many :similar_posts,   :through => :tags,  :source => :tagged_posts, :uniq => true
+  has_many :distinct_tags,   :through => :posts, :source => :tags, :select => "DISTINCT tags.*", :order => "tags.name"
   has_many :post_categories, :through => :posts, :source => :categories
+  has_many :tagging_tags,    :through => :taggings, :source => :tag
+  has_many :tags_with_primary_key, :through => :posts
+
+  has_many :books
+  has_many :subscriptions,        :through => :books
+  has_many :subscribers,          :through => :subscriptions, :order => "subscribers.nick" # through has_many :through (on through reflection)
+  has_many :distinct_subscribers, :through => :subscriptions, :source => :subscriber, :select => "DISTINCT subscribers.*", :order => "subscribers.nick"
 
   has_one :essay, :primary_key => :name, :as => :writer
+  has_one :essay_category, :through => :essay, :source => :category
+  has_one :essay_owner, :through => :essay, :source => :owner
+
+  has_one :essay_2, :primary_key => :name, :class_name => 'Essay', :foreign_key => :author_id
+  has_one :essay_category_2, :through => :essay_2, :source => :category
+
+  has_many :essays, :primary_key => :name, :as => :writer
+  has_many :essay_categories, :through => :essays, :source => :category
+  has_many :essay_owners, :through => :essays, :source => :owner
+
+  has_many :essays_2, :primary_key => :name, :class_name => 'Essay', :foreign_key => :author_id
+  has_many :essay_categories_2, :through => :essays_2, :source => :category
+
+  belongs_to :owned_essay, :primary_key => :name, :class_name => 'Essay'
+  has_one :owned_essay_category, :through => :owned_essay, :source => :category
 
-  belongs_to :author_address, :dependent => :destroy
+  belongs_to :author_address,       :dependent => :destroy
   belongs_to :author_address_extra, :dependent => :delete, :class_name => "AuthorAddress"
 
+  has_many :post_categories, :through => :posts, :source => :categories
+  has_many :category_post_comments, :through => :categories, :source => :post_comments
+
+  has_many :misc_posts, :class_name => 'Post',
+           :conditions => { :posts => { :title => ['misc post by bob', 'misc post by mary'] } }
+  has_many :misc_post_first_blue_tags, :through => :misc_posts, :source => :first_blue_tags
+
+  has_many :misc_post_first_blue_tags_2, :through => :posts, :source => :first_blue_tags_2,
+           :conditions => { :posts => { :title => ['misc post by bob', 'misc post by mary'] } }
+
   scope :relation_include_posts, includes(:posts)
   scope :relation_include_tags, includes(:tags)
 
diff --git a/activerecord/test/models/book.rb b/activerecord/test/models/book.rb
index 1e030b4f59..d27d0af77c 100644
--- a/activerecord/test/models/book.rb
+++ b/activerecord/test/models/book.rb
@@ -1,4 +1,6 @@
 class Book < ActiveRecord::Base
+  has_many :authors
+
   has_many :citations, :foreign_key => 'book1_id'
   has_many :references, :through => :citations, :source => :reference_of, :uniq => true
 
diff --git a/activerecord/test/models/categorization.rb b/activerecord/test/models/categorization.rb
index 45f50e4af3..09489b8ea4 100644
--- a/activerecord/test/models/categorization.rb
+++ b/activerecord/test/models/categorization.rb
@@ -4,6 +4,8 @@ class Categorization < ActiveRecord::Base
   belongs_to :named_category, :class_name => 'Category', :foreign_key => :named_category_name, :primary_key => :name
   belongs_to :author
 
+  has_many :post_taggings, :through => :author, :source => :taggings
+
   belongs_to :author_using_custom_pk,  :class_name => 'Author', :foreign_key => :author_id, :primary_key => :author_address_extra_id
   has_many   :authors_using_custom_pk, :class_name => 'Author', :foreign_key => :id,        :primary_key => :category_id
 end
diff --git a/activerecord/test/models/category.rb b/activerecord/test/models/category.rb
index 8f37433ec6..02b85fd38a 100644
--- a/activerecord/test/models/category.rb
+++ b/activerecord/test/models/category.rb
@@ -22,6 +22,8 @@ class Category < ActiveRecord::Base
   end
 
   has_many :categorizations
+  has_many :post_comments, :through => :posts, :source => :comments
+
   has_many :authors, :through => :categorizations
   has_many :authors_with_select, :through => :categorizations, :source => :author, :select => 'authors.*, categorizations.post_id'
 
diff --git a/activerecord/test/models/club.rb b/activerecord/test/models/club.rb
index c432a6ace8..24a65b0f2f 100644
--- a/activerecord/test/models/club.rb
+++ b/activerecord/test/models/club.rb
@@ -5,6 +5,7 @@ class Club < ActiveRecord::Base
   has_many :current_memberships
   has_one :sponsor
   has_one :sponsored_member, :through => :sponsor, :source => :sponsorable, :source_type => "Member"
+  belongs_to :category
 
   private
 
diff --git a/activerecord/test/models/comment.rb b/activerecord/test/models/comment.rb
index ff533717cc..2a4c37089a 100644
--- a/activerecord/test/models/comment.rb
+++ b/activerecord/test/models/comment.rb
@@ -8,6 +8,7 @@ class Comment < ActiveRecord::Base
               :conditions => { "posts.author_id" => 1 }
 
   belongs_to :post, :counter_cache => true
+  has_many :ratings
 
   def self.what_are_you
     'a comment...'
diff --git a/activerecord/test/models/essay.rb b/activerecord/test/models/essay.rb
index 6c28f5e49b..ec4b982b5b 100644
--- a/activerecord/test/models/essay.rb
+++ b/activerecord/test/models/essay.rb
@@ -1,3 +1,5 @@
 class Essay < ActiveRecord::Base
   belongs_to :writer, :primary_key => :name, :polymorphic => true
+  belongs_to :category, :primary_key => :name
+  has_one :owner, :primary_key => :name
 end
diff --git a/activerecord/test/models/job.rb b/activerecord/test/models/job.rb
index 3333a02e27..f7b0e787b1 100644
--- a/activerecord/test/models/job.rb
+++ b/activerecord/test/models/job.rb
@@ -2,4 +2,6 @@ class Job < ActiveRecord::Base
   has_many :references
   has_many :people, :through => :references
   belongs_to :ideal_reference, :class_name => 'Reference'
+
+  has_many :agents, :through => :people
 end
diff --git a/activerecord/test/models/member.rb b/activerecord/test/models/member.rb
index e6e78f9e45..991e0e051f 100644
--- a/activerecord/test/models/member.rb
+++ b/activerecord/test/models/member.rb
@@ -11,6 +11,17 @@ class Member < ActiveRecord::Base
   has_one :organization, :through => :member_detail
   belongs_to :member_type
 
+  has_many :nested_member_types, :through => :member_detail, :source => :member_type
+  has_one :nested_member_type, :through => :member_detail, :source => :member_type
+
+  has_many :nested_sponsors, :through => :sponsor_club, :source => :sponsor
+  has_one :nested_sponsor, :through => :sponsor_club, :source => :sponsor
+
+  has_many :organization_member_details, :through => :member_detail
+  has_many :organization_member_details_2, :through => :organization, :source => :member_details
+
+  has_one :club_category, :through => :club, :source => :category
+
   has_many :current_memberships
   has_one :club_through_many, :through => :current_memberships, :source => :club
 
diff --git a/activerecord/test/models/member_detail.rb b/activerecord/test/models/member_detail.rb
index 94f59e5794..fe619f8732 100644
--- a/activerecord/test/models/member_detail.rb
+++ b/activerecord/test/models/member_detail.rb
@@ -2,4 +2,6 @@ class MemberDetail < ActiveRecord::Base
   belongs_to :member
   belongs_to :organization
   has_one :member_type, :through => :member
+
+  has_many :organization_member_details, :through => :organization, :source => :member_details
 end
diff --git a/activerecord/test/models/organization.rb b/activerecord/test/models/organization.rb
index 1da342a0bd..4a4111833f 100644
--- a/activerecord/test/models/organization.rb
+++ b/activerecord/test/models/organization.rb
@@ -2,5 +2,11 @@ class Organization < ActiveRecord::Base
   has_many :member_details
   has_many :members, :through => :member_details
 
+  has_many :authors, :primary_key => :name
+  has_many :author_essay_categories, :through => :authors, :source => :essay_categories
+
+  has_one :author, :primary_key => :name
+  has_one :author_owned_essay_category, :through => :author, :source => :owned_essay_category
+
   scope :clubs, { :from => 'clubs' }
-end
\ No newline at end of file
+end
diff --git a/activerecord/test/models/person.rb b/activerecord/test/models/person.rb
index cc3a4f5f9d..ad59d12672 100644
--- a/activerecord/test/models/person.rb
+++ b/activerecord/test/models/person.rb
@@ -21,6 +21,9 @@ class Person < ActiveRecord::Base
   has_many :agents_of_agents, :through => :agents, :source => :agents
   belongs_to :number1_fan, :class_name => 'Person'
 
+  has_many :agents_posts, :through => :agents, :source => :posts
+  has_many :agents_posts_authors, :through => :agents_posts, :source => :author
+
   scope :males, :conditions => { :gender => 'M' }
   scope :females, :conditions => { :gender => 'F' }
 end
diff --git a/activerecord/test/models/post.rb b/activerecord/test/models/post.rb
index a342aaf60b..82894a3d57 100644
--- a/activerecord/test/models/post.rb
+++ b/activerecord/test/models/post.rb
@@ -49,6 +49,9 @@ class Post < ActiveRecord::Base
   has_many :special_comments
   has_many :nonexistant_comments, :class_name => 'Comment', :conditions => 'comments.id < 0'
 
+  has_many :special_comments_ratings, :through => :special_comments, :source => :ratings
+  has_many :special_comments_ratings_taggings, :through => :special_comments_ratings, :source => :taggings
+
   has_and_belongs_to_many :categories
   has_and_belongs_to_many :special_categories, :join_table => "categories_posts", :association_foreign_key => 'category_id'
 
@@ -70,11 +73,17 @@ class Post < ActiveRecord::Base
   has_many :tags_with_destroy, :through => :taggings, :source => :tag, :dependent => :destroy
   has_many :tags_with_nullify, :through => :taggings, :source => :tag, :dependent => :nullify
 
-  has_many :misc_tags, :through => :taggings, :source => :tag, :conditions => "tags.name = 'Misc'"
+  has_many :misc_tags, :through => :taggings, :source => :tag, :conditions => { :tags => { :name => 'Misc' } }
   has_many :funky_tags, :through => :taggings, :source => :tag
   has_many :super_tags, :through => :taggings
+  has_many :tags_with_primary_key, :through => :taggings, :source => :tag_with_primary_key
   has_one :tagging, :as => :taggable
 
+  has_many :first_taggings, :as => :taggable, :class_name => 'Tagging', :conditions => { :taggings => { :comment => 'first' } }
+  has_many :first_blue_tags, :through => :first_taggings, :source => :tag, :conditions => { :tags => { :name => 'Blue' } }
+
+  has_many :first_blue_tags_2, :through => :taggings, :source => :blue_tag, :conditions => { :taggings => { :comment => 'first' } }
+
   has_many :invalid_taggings, :as => :taggable, :class_name => "Tagging", :conditions => 'taggings.id < 0'
   has_many :invalid_tags, :through => :invalid_taggings, :source => :tag
 
diff --git a/activerecord/test/models/rating.rb b/activerecord/test/models/rating.rb
new file mode 100644
index 0000000000..25a52c4ad7
--- /dev/null
+++ b/activerecord/test/models/rating.rb
@@ -0,0 +1,4 @@
+class Rating < ActiveRecord::Base
+  belongs_to :comment
+  has_many :taggings, :as => :taggable
+end
diff --git a/activerecord/test/models/reference.rb b/activerecord/test/models/reference.rb
index 06c4f79ef3..e33a0f2acc 100644
--- a/activerecord/test/models/reference.rb
+++ b/activerecord/test/models/reference.rb
@@ -2,6 +2,8 @@ class Reference < ActiveRecord::Base
   belongs_to :person
   belongs_to :job
 
+  has_many :agents_posts_authors, :through => :person
+
   class << self
     attr_accessor :make_comments
   end
diff --git a/activerecord/test/models/tagging.rb b/activerecord/test/models/tagging.rb
index 231d2b5890..ef323df158 100644
--- a/activerecord/test/models/tagging.rb
+++ b/activerecord/test/models/tagging.rb
@@ -6,6 +6,8 @@ class Tagging < ActiveRecord::Base
   belongs_to :tag, :include => :tagging
   belongs_to :super_tag,   :class_name => 'Tag', :foreign_key => 'super_tag_id'
   belongs_to :invalid_tag, :class_name => 'Tag', :foreign_key => 'tag_id'
+  belongs_to :blue_tag,    :class_name => 'Tag', :foreign_key => :tag_id, :conditions => { :tags => { :name => 'Blue' } }
+  belongs_to :tag_with_primary_key, :class_name => 'Tag', :foreign_key => :tag_id, :primary_key => :custom_primary_key
   belongs_to :interpolated_tag, :class_name => 'Tag', :foreign_key => :tag_id, :conditions => proc { "1 = #{1}" }
   belongs_to :taggable, :polymorphic => true, :counter_cache => true
   has_many :things, :through => :taggable
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index 0b3865fc78..362475de36 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -49,6 +49,8 @@ ActiveRecord::Schema.define do
     t.string :name, :null => false
     t.integer :author_address_id
     t.integer :author_address_extra_id
+    t.string :organization_id
+    t.string :owned_essay_id
   end
 
   create_table :author_addresses, :force => true do |t|
@@ -75,6 +77,7 @@ ActiveRecord::Schema.define do
   end
 
   create_table :books, :force => true do |t|
+    t.integer :author_id
     t.column :name, :string
   end
 
@@ -123,6 +126,7 @@ ActiveRecord::Schema.define do
 
   create_table :clubs, :force => true do |t|
     t.string :name
+    t.integer :category_id
   end
 
   create_table :collections, :force => true do |t|
@@ -216,6 +220,8 @@ ActiveRecord::Schema.define do
     t.string :name
     t.string :writer_id
     t.string :writer_type
+    t.string :category_id
+    t.string :author_id
   end
 
   create_table :events, :force => true do |t|
@@ -393,6 +399,7 @@ ActiveRecord::Schema.define do
     t.string :name
     t.column :updated_at, :datetime
     t.column :happy_at,   :datetime
+    t.string :essay_id
   end
 
   create_table :paint_colors, :force => true do |t|
@@ -482,6 +489,11 @@ ActiveRecord::Schema.define do
     t.string :type
   end
 
+  create_table :ratings, :force => true do |t|
+    t.integer :comment_id
+    t.integer :value
+  end
+
   create_table :readers, :force => true do |t|
     t.integer :post_id, :null => false
     t.integer :person_id, :null => false
@@ -553,6 +565,7 @@ ActiveRecord::Schema.define do
     t.column :super_tag_id, :integer
     t.column :taggable_type, :string
     t.column :taggable_id, :integer
+    t.string :comment
   end
 
   create_table :tasks, :force => true do |t|
@@ -677,6 +690,9 @@ ActiveRecord::Schema.define do
     t.integer :molecule_id
     t.string :name
   end
+  create_table :weirds, :force => true do |t|
+    t.string 'a$b'
+  end
 
   except 'SQLite' do
     # fk_test_has_fk should be before fk_test_has_pk
diff --git a/activesupport/lib/active_support/json/backends/yaml.rb b/activesupport/lib/active_support/json/backends/yaml.rb
index 077eda548a..e25e29d36b 100644
--- a/activesupport/lib/active_support/json/backends/yaml.rb
+++ b/activesupport/lib/active_support/json/backends/yaml.rb
@@ -29,7 +29,7 @@ module ActiveSupport
           def convert_json_to_yaml(json) #:nodoc:
             require 'strscan' unless defined? ::StringScanner
             scanner, quoting, marks, pos, times = ::StringScanner.new(json), false, [], nil, []
-            while scanner.scan_until(/(\\['"]|['":,\\]|\\.)/)
+            while scanner.scan_until(/(\\['"]|['":,\\]|\\.|[\]])/)
               case char = scanner[1]
               when '"', "'"
                 if !quoting
@@ -43,7 +43,7 @@ module ActiveSupport
                   end
                   quoting = false
                 end
-              when ":",","
+              when ":",",", "]"
                 marks << scanner.pos - 1 unless quoting
               when "\\"
                 scanner.skip(/\\/)
@@ -70,9 +70,11 @@ module ActiveSupport
               left_pos.each_with_index do |left, i|
                 scanner.pos = left.succ
                 chunk = scanner.peek(right_pos[i] - scanner.pos + 1)
-                # overwrite the quotes found around the dates with spaces
-                while times.size > 0 && times[0] <= right_pos[i]
-                  chunk.insert(times.shift - scanner.pos - 1, '! ')
+                if ActiveSupport.parse_json_times
+                  # overwrite the quotes found around the dates with spaces
+                  while times.size > 0 && times[0] <= right_pos[i]
+                    chunk.insert(times.shift - scanner.pos - 1, '! ')
+                  end
                 end
                 chunk.gsub!(/\\([\\\/]|u[[:xdigit:]]{4})/) do
                   ustr = $1
diff --git a/activesupport/test/json/decoding_test.rb b/activesupport/test/json/decoding_test.rb
index 24d9f88c09..88cf97de7e 100644
--- a/activesupport/test/json/decoding_test.rb
+++ b/activesupport/test/json/decoding_test.rb
@@ -17,6 +17,8 @@ class TestJSONDecoding < ActiveSupport::TestCase
     %({"matzue": "松江", "asakusa": "浅草"}) => {"matzue" => "松江", "asakusa" => "浅草"},
     %({"a": "2007-01-01"})                       => {'a' => Date.new(2007, 1, 1)},
     %({"a": "2007-01-01 01:12:34 Z"})            => {'a' => Time.utc(2007, 1, 1, 1, 12, 34)},
+    %(["2007-01-01 01:12:34 Z"])                 => [Time.utc(2007, 1, 1, 1, 12, 34)],
+    %(["2007-01-01 01:12:34 Z", "2007-01-01 01:12:35 Z"]) => [Time.utc(2007, 1, 1, 1, 12, 34), Time.utc(2007, 1, 1, 1, 12, 35)],
     # no time zone
     %({"a": "2007-01-01 01:12:34"})              => {'a' => "2007-01-01 01:12:34"},
     # invalid date
@@ -72,13 +74,11 @@ class TestJSONDecoding < ActiveSupport::TestCase
         end
       end
     end
-  end
 
-  if backends.include?("JSONGem")
-    test "json decodes time json with time parsing disabled" do
+    test "json decodes time json with time parsing disabled with the #{backend} backend" do
       ActiveSupport.parse_json_times = false
       expected = {"a" => "2007-01-01 01:12:34 Z"}
-      ActiveSupport::JSON.with_backend "JSONGem" do
+      ActiveSupport::JSON.with_backend backend do
         assert_equal expected, ActiveSupport::JSON.decode(%({"a": "2007-01-01 01:12:34 Z"}))
       end
     end
diff --git a/railties/guides/source/active_record_querying.textile b/railties/guides/source/active_record_querying.textile
index ed3968e226..2c5d9e67e3 100644
--- a/railties/guides/source/active_record_querying.textile
+++ b/railties/guides/source/active_record_querying.textile
@@ -76,7 +76,7 @@ Primary operation of <tt>Model.find(options)</tt> can be summarized as:
 
 h4. Retrieving a Single Object
 
-Active Record lets you retrieve a single object using three different ways.
+Active Record lets you retrieve a single object using five different ways.
 
 h5. Using a Primary Key
 
@@ -130,6 +130,40 @@ SELECT * FROM clients ORDER BY clients.id DESC LIMIT 1
 
 <tt>Model.last</tt> returns +nil+ if no matching record is found. No exception will be raised.
 
+h5. +first!+
+
+<tt>Model.first!</tt> finds the first record. For example:
+
+<ruby>
+client = Client.first!
+=> #<Client id: 1, first_name: "Lifo">
+</ruby>
+
+SQL equivalent of the above is:
+
+<sql>
+SELECT * FROM clients LIMIT 1
+</sql>
+
+<tt>Model.first!</tt> raises +RecordNotFound+ if no matching record is found.
+
+h5. +last!+
+
+<tt>Model.last!</tt> finds the last record. For example:
+
+<ruby>
+client = Client.last!
+=> #<Client id: 221, first_name: "Russel">
+</ruby>
+
+SQL equivalent of the above is:
+
+<sql>
+SELECT * FROM clients ORDER BY clients.id DESC LIMIT 1
+</sql>
+
+<tt>Model.last!</tt> raises +RecordNotFound+ if no matching record is found.
+
 h4. Retrieving Multiple Objects
 
 h5. Using Multiple Primary Keys
@@ -747,6 +781,22 @@ h4. Specifying Conditions on Eager Loaded Associations
 
 Even though Active Record lets you specify conditions on the eager loaded associations just like +joins+, the recommended way is to use "joins":#joining-tables instead.
 
+However if you must do this, you may use +where+ as you would normally.
+
+<ruby>
+Post.includes(:comments).where("comments.visible", true)
+</ruby>
+
+This would generate a query which contains a +LEFT OUTER JOIN+ whereas the +joins+ method would generate one using the +INNER JOIN+ function instead.
+
+<ruby>
+  SELECT "posts"."id" AS t0_r0, ... "comments"."updated_at" AS t1_r5 FROM "posts" LEFT OUTER JOIN "comments" ON "comments"."post_id" = "posts"."id" WHERE (comments.visible)
+</ruby>
+
+If there was no +where+ condition, this would generate the normal set of two queries.
+
+If, in the case of this +includes+ query, there were no comments for any posts, all the posts would still be loaded. By using +joins+ (an INNER JOIN), the join conditions *must* match, otherwise no records will be returned.
+
 h3. Scopes
 
 Scoping allows you to specify commonly-used ARel queries which can be referenced as method calls on the association objects or models. With these scopes, you can use every method previously covered such as +where+, +joins+ and +includes+. All scope methods will return an +ActiveRecord::Relation+ object which will allow for further methods (such as other scopes) to be called on it.
diff --git a/railties/guides/source/active_record_validations_callbacks.textile b/railties/guides/source/active_record_validations_callbacks.textile
index e5349d546c..6c80ec39f2 100644
--- a/railties/guides/source/active_record_validations_callbacks.textile
+++ b/railties/guides/source/active_record_validations_callbacks.textile
@@ -83,7 +83,7 @@ The following methods skip validations, and will save the object to the database
 * +increment_counter+
 * +toggle!+
 * +update_all+
-* +update_attribute+
+* +update_column+
 * +update_counters+
 
 Note that +save+ also has the ability to skip validations if passed +:validate => false+ as argument. This technique should be used with caution.
@@ -964,7 +964,6 @@ The following methods trigger callbacks:
 * +save(false)+
 * +toggle!+
 * +update+
-* +update_attribute+
 * +update_attributes+
 * +update_attributes!+
 * +valid?+
@@ -993,6 +992,7 @@ Just as with validations, it's also possible to skip callbacks. These methods sh
 * +increment+
 * +increment_counter+
 * +toggle+
+* +update_column+
 * +update_all+
 * +update_counters+
 
diff --git a/railties/guides/source/caching_with_rails.textile b/railties/guides/source/caching_with_rails.textile
index 1b5ec40d16..297ba2d661 100644
--- a/railties/guides/source/caching_with_rails.textile
+++ b/railties/guides/source/caching_with_rails.textile
@@ -65,7 +65,7 @@ end
 
 If you want a more complicated expiration scheme, you can use cache sweepers to expire cached objects when things change. This is covered in the section on Sweepers.
 
-Note: Page caching ignores all parameters. For example +/products?page=1+ will be written out to the filesystem as +products.html+ with no reference to the +page+ parameter. Thus, if someone requests +/products?page=2+ later, they will get the cached first page. Be careful when page caching GET parameters in the URL!
+NOTE: Page caching ignores all parameters. For example +/products?page=1+ will be written out to the filesystem as +products.html+ with no reference to the +page+ parameter. Thus, if someone requests +/products?page=2+ later, they will get the cached first page. Be careful when page caching GET parameters in the URL!
 
 INFO: Page caching runs in an after filter. Thus, invalid requests won't generate spurious cache entries as long as you halt them. Typically, a redirection in some before filter that checks request preconditions does the job.
 
diff --git a/railties/guides/source/getting_started.textile b/railties/guides/source/getting_started.textile
index e94bdc97b0..0661549644 100644
--- a/railties/guides/source/getting_started.textile
+++ b/railties/guides/source/getting_started.textile
@@ -149,7 +149,7 @@ Usually run this as the root user:
 # gem install rails
 </shell>
 
-TIP. If you're working on Windows, you should be aware that the vast majority of Rails development is done in Unix environments. While Ruby and Rails themselves install easily using for example "Ruby Installer":http://rubyinstaller.org/, the supporting ecosystem often assumes you are able to build C-based rubygems and work in a command window. If at all possible, we suggest that you install a Linux virtual machine and use that for Rails development, instead of using Windows.
+TIP. If you're working on Windows, you can quickly install Ruby and Rails with "Rails Installer":http://railsinstaller.org.
 
 h4. Creating the Blog Application
 
diff --git a/railties/lib/rails/generators/rails/plugin_new/plugin_new_generator.rb b/railties/lib/rails/generators/rails/plugin_new/plugin_new_generator.rb
index c373ca5e67..3cf8410d1e 100644
--- a/railties/lib/rails/generators/rails/plugin_new/plugin_new_generator.rb
+++ b/railties/lib/rails/generators/rails/plugin_new/plugin_new_generator.rb
@@ -62,7 +62,7 @@ task :default => :test
     end
 
     def generate_test_dummy(force = false)
-      opts = (options || {}).slice(:skip_active_record, :skip_javascript, :database, :javascript)
+      opts = (options || {}).slice(:skip_active_record, :skip_javascript, :database, :javascript, :quiet, :pretend, :force, :skip)
       opts[:force] = force
 
       invoke Rails::Generators::AppGenerator,
diff --git a/railties/lib/rails/railtie/configuration.rb b/railties/lib/rails/railtie/configuration.rb
index e4368866a1..2c7b5bc048 100644
--- a/railties/lib/rails/railtie/configuration.rb
+++ b/railties/lib/rails/railtie/configuration.rb
@@ -31,26 +31,34 @@ module Rails
         app_generators(&block)
       end
 
+      # First configurable block to run. Called before any initializers are run.
       def before_configuration(&block)
         ActiveSupport.on_load(:before_configuration, :yield => true, &block)
       end
 
+      # Third configurable block to run. Does not run if config.cache_classes
+      # set to false.
       def before_eager_load(&block)
         ActiveSupport.on_load(:before_eager_load, :yield => true, &block)
       end
 
+      # Second configurable block to run. Called before frameworks initialize.
       def before_initialize(&block)
         ActiveSupport.on_load(:before_initialize, :yield => true, &block)
       end
 
+      # Last configurable block to run. Called after frameworks initialize.
       def after_initialize(&block)
         ActiveSupport.on_load(:after_initialize, :yield => true, &block)
       end
 
+      # Array of callbacks defined by #to_prepare.
       def to_prepare_blocks
         @@to_prepare_blocks ||= []
       end
 
+      # Defines generic callbacks to run before #after_initialize. Useful for
+      # Rails::Railtie subclasses.
       def to_prepare(&blk)
         to_prepare_blocks << blk if blk
       end
diff --git a/railties/test/generators/shared_generator_tests.rb b/railties/test/generators/shared_generator_tests.rb
index 592da39ccd..c9c5d2fad2 100644
--- a/railties/test/generators/shared_generator_tests.rb
+++ b/railties/test/generators/shared_generator_tests.rb
@@ -26,8 +26,7 @@ module SharedGeneratorTests
 
   def test_plugin_new_generate_pretend
     run_generator ["testapp", "--pretend"]
-
-    default_files.each{ |path| assert_no_file path }
+    default_files.each{ |path| assert_no_file File.join("testapp",path) }
   end
 
   def test_invalid_database_option_raises_an_error