Merge remote branch 'rails/master' into identity_map

Conflicts:
	activerecord/lib/active_record/associations/association_proxy.rb
	activerecord/lib/active_record/autosave_association.rb
	activerecord/lib/active_record/base.rb
	activerecord/lib/active_record/persistence.rb

41 files changed, 708 insertions, 340 deletions

diff --git a/actionpack/lib/abstract_controller/base.rb b/actionpack/lib/abstract_controller/base.rb
index f83eaded88..c384fd0978 100644
--- a/actionpack/lib/abstract_controller/base.rb
+++ b/actionpack/lib/abstract_controller/base.rb
@@ -31,10 +31,9 @@ module AbstractController
       # A list of all internal methods for a controller. This finds the first
       # abstract superclass of a controller, and gets a list of all public
       # instance methods on that abstract class. Public instance methods of
-      # a controller would normally be considered action methods, so we
-      # are removing those methods on classes declared as abstract
-      # (ActionController::Metal and ActionController::Base are defined
-      # as abstract)
+      # a controller would normally be considered action methods, so methods
+      # declared on abstract classes are being removed.
+      # (ActionController::Metal and ActionController::Base are defined as abstract)
       def internal_methods
         controller = self
         controller = controller.superclass until controller.abstract?
diff --git a/actionpack/lib/abstract_controller/layouts.rb b/actionpack/lib/abstract_controller/layouts.rb
index b68c7d9216..606f7eedec 100644
--- a/actionpack/lib/abstract_controller/layouts.rb
+++ b/actionpack/lib/abstract_controller/layouts.rb
@@ -235,13 +235,10 @@ module AbstractController
         controller_path
       end
 
-      # Takes the specified layout and creates a _layout method to be called
-      # by _default_layout
+      # Creates a _layout method to be called by _default_layout .
       #
-      # If there is no explicit layout specified:
-      # If a layout is found in the view paths with the controller's
-      # name, return that string. Otherwise, use the superclass'
-      # layout (which might also be implied)
+      # If a layout is not explicitly mentioned then look for a layout with the controller's name.
+      # if nothing is found then try same procedure to find super class's layout.
       def _write_layout_method
         remove_possible_method(:_layout)
 
diff --git a/actionpack/lib/abstract_controller/rendering.rb b/actionpack/lib/abstract_controller/rendering.rb
index ba31e2b1ea..91b75273fa 100644
--- a/actionpack/lib/abstract_controller/rendering.rb
+++ b/actionpack/lib/abstract_controller/rendering.rb
@@ -128,7 +128,7 @@ module AbstractController
       hash = {}
       variables  = instance_variable_names
       variables -= protected_instance_variables if respond_to?(:protected_instance_variables)
-      variables.each { |name| hash[name.to_s[1..-1]] = instance_variable_get(name) }
+      variables.each { |name| hash[name.to_s[1, name.length]] = instance_variable_get(name) }
       hash
     end
 
diff --git a/actionpack/lib/action_controller/caching/actions.rb b/actionpack/lib/action_controller/caching/actions.rb
index d69d96b974..a4bac3caed 100644
--- a/actionpack/lib/action_controller/caching/actions.rb
+++ b/actionpack/lib/action_controller/caching/actions.rb
@@ -4,25 +4,26 @@ module ActionController #:nodoc:
   module Caching
     # Action caching is similar to page caching by the fact that the entire
     # output of the response is cached, but unlike page caching, every
-    # request still goes through the Action Pack. The key benefit
-    # of this is that filters are run before the cache is served, which
-    # allows for authentication and other restrictions on whether someone
-    # is allowed to see the cache. Example:
+    # request still goes through Action Pack. The key benefit of this is
+    # that filters run before the cache is served, which allows for
+    # authentication and other restrictions on whether someone is allowed
+    # to execute such action. Example:
     #
     #   class ListsController < ApplicationController
     #     before_filter :authenticate, :except => :public
+    #
     #     caches_page   :public
-    #     caches_action :index, :show, :feed
+    #     caches_action :index, :show
     #   end
     #
-    # In this example, the public action doesn't require authentication,
-    # so it's possible to use the faster page caching method. But both
-    # the show and feed action are to be shielded behind the authenticate
-    # filter, so we need to implement those as action caches.
+    # In this example, the +public+ action doesn't require authentication
+    # so it's possible to use the faster page caching. On the other hand
+    # +index+ and +show+ require authentication. They can still be cached,
+    # but we need action caching for them.
     #
-    # Action caching internally uses the fragment caching and an around
-    # filter to do the job. The fragment cache is named according to both
-    # the current host and the path. So a page that is accessed at
+    # Action caching uses fragment caching internally and an around
+    # filter to do the job. The fragment cache is named according to
+    # the host and path of the request. A page that is accessed at
     # <tt>http://david.example.com/lists/show/1</tt> will result in a fragment named
     # <tt>david.example.com/lists/show/1</tt>. This allows the cacher to
     # differentiate between <tt>david.example.com/lists/</tt> and
@@ -38,19 +39,23 @@ module ActionController #:nodoc:
     # <tt>:action => 'list', :format => :xml</tt>.
     #
     # You can set modify the default action cache path by passing a
-    # :cache_path option.  This will be passed directly to
-    # ActionCachePath.path_for.  This is handy for actions with multiple
-    # possible routes that should be cached differently.  If a block is
-    # given, it is called with the current controller instance.
+    # <tt>:cache_path</tt> option.  This will be passed directly to
+    # <tt>ActionCachePath.path_for</tt>.  This is handy for actions with
+    # multiple possible routes that should be cached differently. If a
+    # block is given, it is called with the current controller instance.
+    #
+    # And you can also use <tt>:if</tt> (or <tt>:unless</tt>) to pass a
+    # proc that specifies when the action should be cached.
     #
-    # And you can also use :if (or :unless) to pass a Proc that
-    # specifies when the action should be cached.
+    # Finally, if you are using memcached, you can also pass <tt>:expires_in</tt>.
     #
-    # Finally, if you are using memcached, you can also pass :expires_in.
+    # The following example depicts some of the points made above:
     #
     #   class ListsController < ApplicationController
     #     before_filter :authenticate, :except => :public
-    #     caches_page   :public
+    #
+    #     caches_page :public
+    #
     #     caches_action :index, :if => proc do |c|
     #       !c.request.format.json?  # cache if is not a JSON request
     #     end
@@ -58,19 +63,28 @@ module ActionController #:nodoc:
     #     caches_action :show, :cache_path => { :project => 1 },
     #       :expires_in => 1.hour
     #
-    #     caches_action :feed, :cache_path => proc do |controller|
-    #       if controller.params[:user_id]
-    #         controller.send(:user_list_url,
-    #           controller.params[:user_id], controller.params[:id])
+    #     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])
     #       else
-    #         controller.send(:list_url, controller.params[:id])
+    #         c.send(:list_url, c.params[:id])
     #       end
     #     end
     #   end
     #
-    # If you pass :layout => false, it will only cache your action
-    # content. It is useful when your layout has dynamic information.
+    # If you pass <tt>:layout => false</tt>, it will only cache your action
+    # content. That's useful when your layout has dynamic information.
+    #
+    # Warning: If the format of the request is determined by the Accept HTTP
+    # header the Content-Type of the cached response could be wrong because
+    # no information about the MIME type is stored in the cache key. So, if
+    # you first ask for MIME type M in the Accept header, a cache entry is
+    # created, and then perform a second resquest to the same resource asking
+    # for a different MIME type, you'd get the content cached for M.
     #
+    # The <tt>:format</tt> parameter is taken into account though. The safest
+    # way to cache by MIME type is to pass the format in the route.
     module Actions
       extend ActiveSupport::Concern
 
diff --git a/actionpack/lib/action_controller/caching/pages.rb b/actionpack/lib/action_controller/caching/pages.rb
index 104157d0b1..3e57d2c236 100644
--- a/actionpack/lib/action_controller/caching/pages.rb
+++ b/actionpack/lib/action_controller/caching/pages.rb
@@ -70,9 +70,9 @@ module ActionController #:nodoc:
 
         # Manually cache the +content+ in the key determined by +path+. Example:
         #   cache_page "I'm the cached content", "/lists/show"
-        def cache_page(content, path)
+        def cache_page(content, path, extension = nil)
           return unless perform_caching
-          path = page_cache_path(path)
+          path = page_cache_path(path, extension)
 
           instrument_page_cache :write_page, path do
             FileUtils.makedirs(File.dirname(path))
@@ -97,14 +97,16 @@ module ActionController #:nodoc:
         end
 
         private
-          def page_cache_file(path)
+          def page_cache_file(path, extension)
             name = (path.empty? || path == "/") ? "/index" : URI.parser.unescape(path.chomp('/'))
-            name << page_cache_extension unless (name.split('/').last || name).include? '.'
+            unless (name.split('/').last || name).include? '.'
+              name << (extension || self.page_cache_extension)
+            end
             return name
           end
 
-          def page_cache_path(path)
-            page_cache_directory + page_cache_file(path)
+          def page_cache_path(path, extension = nil)
+            page_cache_directory + page_cache_file(path, extension)
           end
 
           def instrument_page_cache(name, path)
@@ -145,7 +147,11 @@ module ActionController #:nodoc:
             request.path
         end
 
-        self.class.cache_page(content || response.body, path)
+        if (type = Mime::LOOKUP[self.content_type]) && (type_symbol = type.symbol).present?
+          extension = ".#{type_symbol}"
+        end
+
+        self.class.cache_page(content || response.body, path, extension)
       end
 
     end
diff --git a/actionpack/lib/action_controller/metal/mime_responds.rb b/actionpack/lib/action_controller/metal/mime_responds.rb
index f7dd0dcb69..9ba37134b8 100644
--- a/actionpack/lib/action_controller/metal/mime_responds.rb
+++ b/actionpack/lib/action_controller/metal/mime_responds.rb
@@ -258,9 +258,8 @@ module ActionController #:nodoc:
     # nil if :not_acceptable was sent to the client.
     #
     def retrieve_response_from_mimes(mimes=nil, &block)
-      collector = Collector.new { default_render }
       mimes ||= collect_mimes_from_class_level
-      mimes.each { |mime| collector.send(mime) }
+      collector = Collector.new(mimes) { default_render }
       block.call(collector) if block_given?
 
       if format = request.negotiate_mime(collector.order)
@@ -277,8 +276,9 @@ module ActionController #:nodoc:
       include AbstractController::Collector
       attr_accessor :order
 
-      def initialize(&block)
+      def initialize(mimes, &block)
         @order, @responses, @default_response = [], {}, block
+        mimes.each { |mime| send(mime) }
       end
 
       def any(*args, &block)
@@ -291,7 +291,7 @@ module ActionController #:nodoc:
       alias :all :any
 
       def custom(mime_type, &block)
-        mime_type = mime_type.is_a?(Mime::Type) ? mime_type : Mime::Type.lookup(mime_type.to_s)
+        mime_type = Mime::Type.lookup(mime_type.to_s) unless mime_type.is_a?(Mime::Type)
         @order << mime_type
         @responses[mime_type] ||= block
       end
diff --git a/actionpack/lib/action_controller/metal/renderers.rb b/actionpack/lib/action_controller/metal/renderers.rb
index f9b226b7c9..d6f6ab1855 100644
--- a/actionpack/lib/action_controller/metal/renderers.rb
+++ b/actionpack/lib/action_controller/metal/renderers.rb
@@ -15,30 +15,12 @@ module ActionController
     end
 
     module ClassMethods
-      def _write_render_options
-        renderers = _renderers.map do |name, value|
-          <<-RUBY_EVAL
-            if options.key?(:#{name})
-              _process_options(options)
-              return _render_option_#{name}(options.delete(:#{name}), options)
-            end
-          RUBY_EVAL
-        end
-
-        class_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1
-          def _handle_render_options(options)
-            #{renderers.join}
-          end
-        RUBY_EVAL
-      end
-
       def use_renderers(*args)
         new = _renderers.dup
         args.each do |key|
           new[key] = RENDERERS[key]
         end
         self._renderers = new.freeze
-        _write_render_options
       end
       alias use_renderer use_renderers
     end
@@ -47,31 +29,33 @@ module ActionController
       _handle_render_options(options) || super
     end
 
+    def _handle_render_options(options)
+      _renderers.each do |name, value|
+        if options.key?(name.to_sym)
+          _process_options(options)
+          return send("_render_option_#{name}", options.delete(name.to_sym), options)
+        end
+      end
+      nil
+    end
+
     RENDERERS = {}
     def self.add(key, &block)
       define_method("_render_option_#{key}", &block)
       RENDERERS[key] = block
-      All._write_render_options
     end
 
     module All
       extend ActiveSupport::Concern
       include Renderers
 
-      INCLUDED = []
       included do
         self._renderers = RENDERERS
-        _write_render_options
-        INCLUDED << self
-      end
-
-      def self._write_render_options
-        INCLUDED.each(&:_write_render_options)
       end
     end
 
     add :json do |json, options|
-      json = json.to_json(options) unless json.respond_to?(:to_str)
+      json = json.to_json(options) unless json.kind_of?(String)
       json = "#{options[:callback]}(#{json})" unless options[:callback].blank?
       self.content_type ||= Mime::JSON
       self.response_body  = json
diff --git a/actionpack/lib/action_controller/metal/rendering.rb b/actionpack/lib/action_controller/metal/rendering.rb
index e524e546ad..14cc547dd0 100644
--- a/actionpack/lib/action_controller/metal/rendering.rb
+++ b/actionpack/lib/action_controller/metal/rendering.rb
@@ -20,36 +20,35 @@ module ActionController
 
     private
 
-      # Normalize arguments by catching blocks and setting them on :update.
-      def _normalize_args(action=nil, options={}, &blk) #:nodoc:
-        options = super
-        options[:update] = blk if block_given?
-        options
-      end
-
-      # Normalize both text and status options.
-      def _normalize_options(options) #:nodoc:
-        if options.key?(:text) && options[:text].respond_to?(:to_text)
-          options[:text] = options[:text].to_text
-        end
+    # Normalize arguments by catching blocks and setting them on :update.
+    def _normalize_args(action=nil, options={}, &blk) #:nodoc:
+      options = super
+      options[:update] = blk if block_given?
+      options
+    end
 
-        if options[:status]
-          options[:status] = Rack::Utils.status_code(options[:status])
-        end
+    # Normalize both text and status options.
+    def _normalize_options(options) #:nodoc:
+      if options.key?(:text) && options[:text].respond_to?(:to_text)
+        options[:text] = options[:text].to_text
+      end
 
-        super
+      if options[:status]
+        options[:status] = Rack::Utils.status_code(options[:status])
       end
 
-      # Process controller specific options, as status, content-type and location.
-      def _process_options(options) #:nodoc:
-        status, content_type, location = options.values_at(:status, :content_type, :location)
+      super
+    end
 
-        self.status = status if status
-        self.content_type = content_type if content_type
-        self.headers["Location"] = url_for(location) if location
+    # Process controller specific options, as status, content-type and location.
+    def _process_options(options) #:nodoc:
+      status, content_type, location = options.values_at(:status, :content_type, :location)
 
-        super
-      end
+      self.status = status if status
+      self.content_type = content_type if content_type
+      self.headers["Location"] = url_for(location) if location
 
+      super
+    end
   end
 end
diff --git a/actionpack/lib/action_controller/metal/request_forgery_protection.rb b/actionpack/lib/action_controller/metal/request_forgery_protection.rb
index 02f577647e..148efbb081 100644
--- a/actionpack/lib/action_controller/metal/request_forgery_protection.rb
+++ b/actionpack/lib/action_controller/metal/request_forgery_protection.rb
@@ -53,9 +53,13 @@ module ActionController #:nodoc:
       #   class FooController < ApplicationController
       #     protect_from_forgery :except => :index
       #
-      #     # you can disable csrf protection on controller-by-controller basis:
-      #     skip_before_filter :verify_authenticity_token
-      #   end
+      # You can disable csrf protection on controller-by-controller basis:
+      #
+      #   skip_before_filter :verify_authenticity_token
+      #
+      # It can also be disabled for specific controller actions:
+      #
+      #   skip_before_filter :verify_authenticity_token, :except => [:create]
       #
       # Valid Options:
       #
diff --git a/actionpack/lib/action_controller/metal/url_for.rb b/actionpack/lib/action_controller/metal/url_for.rb
index 333eeaeffb..6fc0cf1fb8 100644
--- a/actionpack/lib/action_controller/metal/url_for.rb
+++ b/actionpack/lib/action_controller/metal/url_for.rb
@@ -6,7 +6,8 @@ module ActionController
 
     def url_options
       @_url_options ||= super.reverse_merge(
-        :host => request.host_with_port,
+        :host => request.host,
+        :port => request.optional_port,
         :protocol => request.protocol,
         :_path_segments => request.symbolized_path_parameters
       ).freeze
@@ -20,5 +21,6 @@ module ActionController
         @_url_options
       end
     end
+
   end
 end
diff --git a/actionpack/lib/action_controller/railtie.rb b/actionpack/lib/action_controller/railtie.rb
index c5a661f2b0..f0c29825ba 100644
--- a/actionpack/lib/action_controller/railtie.rb
+++ b/actionpack/lib/action_controller/railtie.rb
@@ -27,8 +27,8 @@ module ActionController
       options.page_cache_directory ||= paths["public"].first
 
       # make sure readers methods get compiled
-      options.asset_path           ||= nil
-      options.asset_host           ||= nil
+      options.asset_path           ||= app.config.asset_path
+      options.asset_host           ||= app.config.asset_host
 
       ActiveSupport.on_load(:action_controller) do
         include app.routes.mounted_helpers
diff --git a/actionpack/lib/action_controller/railties/paths.rb b/actionpack/lib/action_controller/railties/paths.rb
index 699c44c62c..dce3c2fe88 100644
--- a/actionpack/lib/action_controller/railties/paths.rb
+++ b/actionpack/lib/action_controller/railties/paths.rb
@@ -16,6 +16,14 @@ module ActionController
             if klass.superclass == ActionController::Base && ActionController::Base.include_all_helpers
               klass.helper :all
             end
+
+            if app.config.serve_static_assets && namespace
+              paths = namespace._railtie.config.paths
+
+              klass.config.assets_dir      = paths["public"].first
+              klass.config.javascripts_dir = paths["public/javascripts"].first
+              klass.config.stylesheets_dir = paths["public/stylesheets"].first
+            end
           end
         end
       end
diff --git a/actionpack/lib/action_controller/test_case.rb b/actionpack/lib/action_controller/test_case.rb
index 2b2f647d32..0f43527a56 100644
--- a/actionpack/lib/action_controller/test_case.rb
+++ b/actionpack/lib/action_controller/test_case.rb
@@ -1,6 +1,7 @@
 require 'rack/session/abstract/id'
 require 'active_support/core_ext/object/blank'
 require 'active_support/core_ext/object/to_query'
+require 'active_support/core_ext/class/attribute'
 
 module ActionController
   module TemplateAssertions
@@ -325,11 +326,11 @@ module ActionController
 
         def controller_class=(new_class)
           prepare_controller_class(new_class) if new_class
-          write_inheritable_attribute(:controller_class, new_class)
+          self._controller_class = new_class
         end
 
         def controller_class
-          if current_controller_class = read_inheritable_attribute(:controller_class)
+          if current_controller_class = self._controller_class
             current_controller_class
           else
             self.controller_class = determine_default_controller_class(name)
@@ -442,6 +443,7 @@ module ActionController
       included do
         include ActionController::TemplateAssertions
         include ActionDispatch::Assertions
+        class_attribute :_controller_class
         setup :setup_controller_request_and_response
       end
 
diff --git a/actionpack/lib/action_controller/vendor/html-scanner/html/sanitizer.rb b/actionpack/lib/action_controller/vendor/html-scanner/html/sanitizer.rb
index dceddb9b80..3e5d23b5c1 100644
--- a/actionpack/lib/action_controller/vendor/html-scanner/html/sanitizer.rb
+++ b/actionpack/lib/action_controller/vendor/html-scanner/html/sanitizer.rb
@@ -1,5 +1,5 @@
 require 'set'
-require 'active_support/core_ext/class/inheritable_attributes'
+require 'active_support/core_ext/class/attribute'
 
 module HTML
   class Sanitizer
@@ -60,7 +60,7 @@ module HTML
   class WhiteListSanitizer < Sanitizer
     [:protocol_separator, :uri_attributes, :allowed_attributes, :allowed_tags, :allowed_protocols, :bad_tags,
      :allowed_css_properties, :allowed_css_keywords, :shorthand_css_properties].each do |attr|
-      class_inheritable_accessor attr, :instance_writer => false
+      class_attribute attr, :instance_writer => false
     end
 
     # A regular expression of the valid characters used to separate protocols like
diff --git a/actionpack/lib/action_dispatch.rb b/actionpack/lib/action_dispatch.rb
index 50faf666e6..50d0d191c1 100644
--- a/actionpack/lib/action_dispatch.rb
+++ b/actionpack/lib/action_dispatch.rb
@@ -53,6 +53,7 @@ module ActionDispatch
     autoload :Flash
     autoload :Head
     autoload :ParamsParser
+    autoload :Reloader
     autoload :RemoteIp
     autoload :Rescue
     autoload :ShowExceptions
diff --git a/actionpack/lib/action_dispatch/http/mime_negotiation.rb b/actionpack/lib/action_dispatch/http/mime_negotiation.rb
index b959aa258e..68ba1a81b5 100644
--- a/actionpack/lib/action_dispatch/http/mime_negotiation.rb
+++ b/actionpack/lib/action_dispatch/http/mime_negotiation.rb
@@ -36,19 +36,21 @@ module ActionDispatch
       #
       #   GET /posts/5.xml   | request.format => Mime::XML
       #   GET /posts/5.xhtml | request.format => Mime::HTML
-      #   GET /posts/5       | request.format => Mime::HTML or MIME::JS, or request.accepts.first depending on the value of <tt>ActionController::Base.use_accept_header</tt>
+      #   GET /posts/5       | request.format => Mime::HTML or MIME::JS, or request.accepts.first
       #
       def format(view_path = [])
         formats.first
       end
 
+      BROWSER_LIKE_ACCEPTS = /,\s*\*\/\*|\*\/\*\s*,/
+
       def formats
         accept = @env['HTTP_ACCEPT']
 
         @env["action_dispatch.request.formats"] ||=
           if parameters[:format]
             Array(Mime[parameters[:format]])
-          elsif xhr? || (accept && accept !~ /,\s*\*\/\*/)
+          elsif xhr? || (accept && accept !~ BROWSER_LIKE_ACCEPTS)
             accepts
           else
             [Mime::HTML]
diff --git a/actionpack/lib/action_dispatch/http/mime_type.rb b/actionpack/lib/action_dispatch/http/mime_type.rb
index 8f1c9b6691..5b87a80c1b 100644
--- a/actionpack/lib/action_dispatch/http/mime_type.rb
+++ b/actionpack/lib/action_dispatch/http/mime_type.rb
@@ -80,6 +80,9 @@ module Mime
     end
 
     class << self
+
+      TRAILING_STAR_REGEXP = /(text|application)\/\*/
+
       def lookup(string)
         LOOKUP[string]
       end
@@ -105,15 +108,28 @@ module Mime
 
       def parse(accept_header)
         if accept_header !~ /,/
-          [Mime::Type.lookup(accept_header)]
+          if accept_header =~ TRAILING_STAR_REGEXP
+            parse_data_with_trailing_star($1)
+          else
+            [Mime::Type.lookup(accept_header)]
+          end
         else
           # keep track of creation order to keep the subsequent sort stable
-          list = []
-          accept_header.split(/,/).each_with_index do |header, index|
+          list, index = [], 0
+          accept_header.split(/,/).each do |header|
             params, q = header.split(/;\s*q=/)
-            if params
+            if params.present?
               params.strip!
-              list << AcceptItem.new(index, params, q) unless params.empty?
+
+              if params =~ TRAILING_STAR_REGEXP
+                parse_data_with_trailing_star($1).each do |m|
+                  list << AcceptItem.new(index, m.to_s, q)
+                  index += 1
+                end
+              else
+                list << AcceptItem.new(index, params, q)
+                index += 1
+              end
             end
           end
           list.sort!
@@ -160,6 +176,30 @@ module Mime
           list
         end
       end
+
+      # input: 'text'
+      # returned value:  [Mime::JSON, Mime::XML, Mime::ICS, Mime::HTML, Mime::CSS, Mime::CSV, Mime::JS, Mime::YAML, Mime::TEXT]
+      #
+      # input: 'application'
+      # returned value: [Mime::HTML, Mime::JS, Mime::XML, Mime::YAML, Mime::ATOM, Mime::JSON, Mime::RSS, Mime::URL_ENCODED_FORM]
+      def parse_data_with_trailing_star(input)
+        Mime::SET.select { |m| m =~ input }
+      end
+
+      # This method is opposite of register method.
+      #
+      # Usage:
+      #
+      # Mime::Type.unregister(:mobile)
+      def unregister(symbol)
+        symbol = symbol.to_s.upcase
+        mime = Mime.const_get(symbol)
+        Mime.instance_eval { remove_const(symbol) }
+
+        SET.delete_if { |v| v.eql?(mime) }
+        LOOKUP.delete_if { |k,v| v.eql?(mime) }
+        EXTENSION_LOOKUP.delete_if { |k,v| v.eql?(mime) }
+      end
     end
 
     def initialize(string, symbol = nil, synonyms = [])
diff --git a/actionpack/lib/action_dispatch/http/url.rb b/actionpack/lib/action_dispatch/http/url.rb
index 9c9eed2c6d..796cd8c09b 100644
--- a/actionpack/lib/action_dispatch/http/url.rb
+++ b/actionpack/lib/action_dispatch/http/url.rb
@@ -4,6 +4,75 @@ module ActionDispatch
       mattr_accessor :tld_length
       self.tld_length = 1
 
+      class << self
+        def extract_domain(host, tld_length = @@tld_length)
+          return nil unless named_host?(host)
+          host.split('.').last(1 + tld_length).join('.')
+        end
+
+        def extract_subdomains(host, tld_length = @@tld_length)
+          return [] unless named_host?(host)
+          parts = host.split('.')
+          parts[0..-(tld_length+2)]
+        end
+
+        def extract_subdomain(host, tld_length = @@tld_length)
+          extract_subdomains(host, tld_length).join('.')
+        end
+
+        def url_for(options = {})
+          unless options[:host].present? || options[:only_path].present?
+            raise ArgumentError, 'Missing host to link to! Please provide the :host parameter, set default_url_options[:host], or set :only_path to true'
+          end
+
+          rewritten_url = ""
+
+          unless options[:only_path]
+            rewritten_url << (options[:protocol] || "http")
+            rewritten_url << "://" unless rewritten_url.match("://")
+            rewritten_url << rewrite_authentication(options)
+            rewritten_url << host_or_subdomain_and_domain(options)
+            rewritten_url << ":#{options.delete(:port)}" if options[:port]
+          end
+
+          path = options.delete(:path) || ''
+
+          params = options[:params] || {}
+          params.reject! {|k,v| !v }
+
+          rewritten_url << (options[:trailing_slash] ? path.sub(/\?|\z/) { "/" + $& } : path)
+          rewritten_url << "?#{params.to_query}" unless params.empty?
+          rewritten_url << "##{Rack::Mount::Utils.escape_uri(options[:anchor].to_param.to_s)}" if options[:anchor]
+          rewritten_url
+        end
+
+        private
+
+        def named_host?(host)
+          !(host.nil? || /\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/.match(host))
+        end
+
+        def rewrite_authentication(options)
+          if options[:user] && options[:password]
+            "#{Rack::Utils.escape(options[:user])}:#{Rack::Utils.escape(options[:password])}@"
+          else
+            ""
+          end
+        end
+
+        def host_or_subdomain_and_domain(options)
+          return options[:host] unless options[:subdomain] || options[:domain]
+
+          tld_length = options[:tld_length] || @@tld_length
+
+          host = ""
+          host << (options[:subdomain] || extract_subdomain(options[:host], tld_length))
+          host << "."
+          host << (options[:domain]    || extract_domain(options[:host], tld_length))
+          host
+        end
+      end
+
       # Returns the complete URL used for this request.
       def url
         protocol + host_with_port + fullpath
@@ -36,10 +105,12 @@ module ActionDispatch
 
       # Returns the port number of this request as an integer.
       def port
-        if raw_host_with_port =~ /:(\d+)$/
-          $1.to_i
-        else
-          standard_port
+        @port ||= begin
+          if raw_host_with_port =~ /:(\d+)$/
+            $1.to_i
+          else
+            standard_port
+          end
         end
       end
 
@@ -56,10 +127,16 @@ module ActionDispatch
         port == standard_port
       end
 
-      # Returns a \port suffix like ":8080" if the \port number of this request
+      # Returns a number \port suffix like 8080 if the \port number of this request
       # is not the default HTTP \port 80 or HTTPS \port 443.
+      def optional_port
+        standard_port? ? nil : port
+      end
+
+      # Returns a string \port suffix, including colon, like ":8080" if the \port
+      # number of this request is not the default HTTP \port 80 or HTTPS \port 443.
       def port_string
-        port == standard_port ? '' : ":#{port}"
+        standard_port? ? '' : ":#{port}"
       end
 
       def server_port
@@ -69,9 +146,7 @@ module ActionDispatch
       # Returns the \domain part of a \host, such as "rubyonrails.org" in "www.rubyonrails.org". You can specify
       # a different <tt>tld_length</tt>, such as 2 to catch rubyonrails.co.uk in "www.rubyonrails.co.uk".
       def domain(tld_length = @@tld_length)
-        return nil unless named_host?(host)
-
-        host.split('.').last(1 + tld_length).join('.')
+        ActionDispatch::Http::URL.extract_domain(host, tld_length)
       end
 
       # Returns all the \subdomains as an array, so <tt>["dev", "www"]</tt> would be
@@ -79,19 +154,15 @@ module ActionDispatch
       # such as 2 to catch <tt>["www"]</tt> instead of <tt>["www", "rubyonrails"]</tt>
       # in "www.rubyonrails.co.uk".
       def subdomains(tld_length = @@tld_length)
-        return [] unless named_host?(host)
-        parts = host.split('.')
-        parts[0..-(tld_length+2)]
+        ActionDispatch::Http::URL.extract_subdomains(host, tld_length)
       end
 
+      # Returns all the \subdomains as a string, so <tt>"dev.www"</tt> would be
+      # returned for "dev.www.rubyonrails.org". You can specify a different <tt>tld_length</tt>,
+      # such as 2 to catch <tt>["www"]</tt> instead of <tt>"www.rubyonrails"</tt>
+      # in "www.rubyonrails.co.uk".
       def subdomain(tld_length = @@tld_length)
-        subdomains(tld_length).join('.')
-      end
-
-    private
-
-      def named_host?(host)
-        !(host.nil? || /\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/.match(host))
+        subdomains(tld_length)
       end
     end
   end
diff --git a/actionpack/lib/action_dispatch/middleware/callbacks.rb b/actionpack/lib/action_dispatch/middleware/callbacks.rb
index 0bb950d1cc..5776a7bb27 100644
--- a/actionpack/lib/action_dispatch/middleware/callbacks.rb
+++ b/actionpack/lib/action_dispatch/middleware/callbacks.rb
@@ -1,32 +1,14 @@
 module ActionDispatch
   # Provide callbacks to be executed before and after the request dispatch.
-  #
-  # It also provides a to_prepare callback, which is performed in all requests
-  # in development by only once in production and notification callback for async
-  # operations.
-  #
   class Callbacks
     include ActiveSupport::Callbacks
 
     define_callbacks :call, :rescuable => true
-    define_callbacks :prepare, :scope => :name
 
-    # Add a preparation callback. Preparation callbacks are run before every
-    # request in development mode, and before the first request in production mode.
-    #
-    # If a symbol with a block is given, the symbol is used as an identifier.
-    # That allows to_prepare to be called again with the same identifier to
-    # replace the existing callback. Passing an identifier is a suggested
-    # practice if the code adding a preparation block may be reloaded.
     def self.to_prepare(*args, &block)
-      first_arg = args.first
-      if first_arg.is_a?(Symbol) && block_given?
-        remove_method :"__#{first_arg}" if method_defined?(:"__#{first_arg}")
-        define_method :"__#{first_arg}", &block
-        set_callback(:prepare, :"__#{first_arg}")
-      else
-        set_callback(:prepare, *args, &block)
-      end
+      ActiveSupport::Deprecation.warn "ActionDispatch::Callbacks.to_prepare is deprecated. " <<
+        "Please use ActionDispatch::Reloader.to_prepare instead."
+      ActionDispatch::Reloader.to_prepare(*args, &block)
     end
 
     def self.before(*args, &block)
@@ -37,14 +19,13 @@ module ActionDispatch
       set_callback(:call, :after, *args, &block)
     end
 
-    def initialize(app, prepare_each_request = false)
-      @app, @prepare_each_request = app, prepare_each_request
-      _run_prepare_callbacks
+    def initialize(app, unused = nil)
+      ActiveSupport::Deprecation.warn "Passing a second argument to ActionDispatch::Callbacks.new is deprecated." unless unused.nil?
+      @app = app
     end
 
     def call(env)
       _run_call_callbacks do
-        _run_prepare_callbacks if @prepare_each_request
         @app.call(env)
       end
     end
diff --git a/actionpack/lib/action_dispatch/middleware/cookies.rb b/actionpack/lib/action_dispatch/middleware/cookies.rb
index c4c2e1acd7..f369d2d3c2 100644
--- a/actionpack/lib/action_dispatch/middleware/cookies.rb
+++ b/actionpack/lib/action_dispatch/middleware/cookies.rb
@@ -16,17 +16,23 @@ module ActionDispatch
   # Examples for writing:
   #
   #   # Sets a simple session cookie.
+  #   # This cookie will be deleted when the user's browser is closed.
   #   cookies[:user_name] = "david"
   #
+  #   # Assign an array of values to a cookie.
+  #   cookies[:lat_lon] = [47.68, -122.37]
+  #
   #   # Sets a cookie that expires in 1 hour.
   #   cookies[:login] = { :value => "XJ-122", :expires => 1.hour.from_now }
   #
   #   # Sets a signed cookie, which prevents a user from tampering with its value.
-  #   # You must specify a value in ActionController::Base.cookie_verifier_secret.
-  #   cookies.signed[:remember_me] = [current_user.id, current_user.salt]
+  #   # The cookie is signed by your app's <tt>config.secret_token</tt> value.
+  #   # Rails generates this value by default when you create a new Rails app.
+  #   cookies.signed[:user_id] = current_user.id
   #
   #   # Sets a "permanent" cookie (which expires in 20 years from now).
   #   cookies.permanent[:login] = "XJ-122"
+  #
   #   # You can also chain these methods:
   #   cookies.permanent.signed[:login] = "XJ-122"
   #
@@ -34,6 +40,7 @@ module ActionDispatch
   #
   #   cookies[:user_name] # => "david"
   #   cookies.size        # => 2
+  #   cookies[:lat_lon]   # => [47.68, -122.37]
   #
   # Example for deleting:
   #
@@ -124,8 +131,11 @@ module ActionDispatch
         options[:path] ||= "/"
 
         if options[:domain] == :all
-          @host =~ DOMAIN_REGEXP
-          options[:domain] = ".#{$1}.#{$2}"
+          # if host is not ip and matches domain regexp
+          # (ip confirms to domain regexp so we explicitly check for ip)
+          options[:domain] = if (@host !~ /^[\d.]+$/) && (@host =~ DOMAIN_REGEXP)
+            ".#{$1}.#{$2}"
+          end
         end
       end
 
@@ -275,7 +285,7 @@ module ActionDispatch
             "integrity hash for cookie session data. Use " +
             "config.secret_token = \"some secret phrase of at " +
             "least #{SECRET_MIN_LENGTH} characters\"" +
-            "in config/application.rb"
+            "in config/initializers/secret_token.rb"
         end
 
         if secret.length < SECRET_MIN_LENGTH
diff --git a/actionpack/lib/action_dispatch/middleware/reloader.rb b/actionpack/lib/action_dispatch/middleware/reloader.rb
new file mode 100644
index 0000000000..579b5d8a02
--- /dev/null
+++ b/actionpack/lib/action_dispatch/middleware/reloader.rb
@@ -0,0 +1,65 @@
+module ActionDispatch
+  # ActionDispatch::Reloader provides to_prepare and to_cleanup callbacks.
+  # These are analogs of ActionDispatch::Callback's before and after
+  # callbacks, with the difference that to_cleanup is not called until the
+  # request is fully complete -- that is, after #close has been called on
+  # the request body. This is important for streaming responses such as the
+  # following:
+  #
+  #     self.response_body = lambda { |response, output|
+  #       # code here which refers to application models
+  #     }
+  #
+  # Cleanup callbacks will not be called until after the response_body lambda
+  # is evaluated, ensuring that it can refer to application models and other
+  # classes before they are unloaded.
+  #
+  # By default, ActionDispatch::Reloader is included in the middleware stack
+  # only in the development environment.
+  #
+  class Reloader
+    include ActiveSupport::Callbacks
+
+    define_callbacks :prepare, :scope => :name
+    define_callbacks :cleanup, :scope => :name
+
+    # Add a preparation callback. Preparation callbacks are run before each
+    # request.
+    def self.to_prepare(*args, &block)
+      set_callback(:prepare, *args, &block)
+    end
+
+    # Add a cleanup callback. Cleanup callbacks are run after each request is
+    # complete (after #close is called on the response body).
+    def self.to_cleanup(*args, &block)
+      set_callback(:cleanup, *args, &block)
+    end
+
+    def self.prepare!
+      new(nil).send(:_run_prepare_callbacks)
+    end
+
+    def self.cleanup!
+      new(nil).send(:_run_cleanup_callbacks)
+    end
+
+    def initialize(app)
+      @app = app
+    end
+
+    module CleanupOnClose
+      def close
+        super if defined?(super)
+      ensure
+        ActionDispatch::Reloader.cleanup!
+      end
+    end
+
+    def call(env)
+      _run_prepare_callbacks
+      response = @app.call(env)
+      response[2].extend(CleanupOnClose)
+      response
+    end
+  end
+end
diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index 879ccc5791..f65a294eca 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -2,6 +2,7 @@ require 'erb'
 require 'active_support/core_ext/hash/except'
 require 'active_support/core_ext/object/blank'
 require 'active_support/inflector'
+require 'action_dispatch/routing/redirection'
 
 module ActionDispatch
   module Routing
@@ -246,7 +247,11 @@ module ActionDispatch
         #
         #   root :to => 'pages#main'
         #
-        # You should put the root route at the end of <tt>config/routes.rb</tt>.
+        # For options, see the +match+ method's documentation, as +root+ uses it internally.
+        #
+        # You should put the root route at the top of <tt>config/routes.rb</tt>,
+        # because this means it will be matched first. As this is the most popular route
+        # of most Rails applications, this is beneficial.
         def root(options = {})
           match '/', options.reverse_merge(:as => :root)
         end
@@ -268,18 +273,18 @@ module ActionDispatch
 
         # Mount a Rack-based application to be used within the application.
         #
-        # mount SomeRackApp, :at => "some_route"
+        #   mount SomeRackApp, :at => "some_route"
         #
         # Alternatively:
         #
-        # mount(SomeRackApp => "some_route")
+        #   mount(SomeRackApp => "some_route")
         #
         # All mounted applications come with routing helpers to access them.
         # These are named after the class specified, so for the above example
         # the helper is either +some_rack_app_path+ or +some_rack_app_url+.
         # To customize this helper's name, use the +:as+ option:
         #
-        # mount(SomeRackApp => "some_route", :as => "exciting")
+        #   mount(SomeRackApp => "some_route", :as => "exciting")
         #
         # This will generate the +exciting_path+ and +exciting_url+ helpers
         # which can be used to navigate to this mounted app.
@@ -326,7 +331,7 @@ module ActionDispatch
           end
 
           def define_generate_prefix(app, name)
-            return unless app.respond_to?(:routes)
+            return unless app.respond_to?(:routes) && app.routes.respond_to?(:define_mounted_helper)
 
             _route = @set.named_routes.routes[name.to_sym]
             _routes = @set
@@ -383,39 +388,6 @@ module ActionDispatch
           map_method(:delete, *args, &block)
         end
 
-        # Redirect any path to another path:
-        #
-        #   match "/stories" => redirect("/posts")
-        def redirect(*args)
-          options = args.last.is_a?(Hash) ? args.pop : {}
-
-          path      = args.shift || Proc.new
-          path_proc = path.is_a?(Proc) ? path : proc { |params| (params.empty? || !path.match(/%\{\w*\}/)) ? path : (path % params) }
-          status    = options[:status] || 301
-
-          lambda do |env|
-            req = Request.new(env)
-
-            params = [req.symbolized_path_parameters]
-            params << req if path_proc.arity > 1
-
-            uri = URI.parse(path_proc.call(*params))
-            uri.scheme ||= req.scheme
-            uri.host   ||= req.host
-            uri.port   ||= req.port unless req.standard_port?
-
-            body = %(<html><body>You are being <a href="#{ERB::Util.h(uri.to_s)}">redirected</a>.</body></html>)
-
-            headers = {
-              'Location' => uri.to_s,
-              'Content-Type' => 'text/html',
-              'Content-Length' => body.length.to_s
-            }
-
-            [ status, headers, [body] ]
-          end
-        end
-
         private
           def map_method(method, *args, &block)
             options = args.extract_options!
@@ -439,13 +411,13 @@ module ActionDispatch
       # This will create a number of routes for each of the posts and comments
       # controller. For Admin::PostsController, Rails will create:
       #
-      #   GET	    /admin/photos
-      #   GET	    /admin/photos/new
-      #   POST	  /admin/photos
-      #   GET	    /admin/photos/1
-      #   GET	    /admin/photos/1/edit
-      #   PUT	    /admin/photos/1
-      #   DELETE  /admin/photos/1
+      #   GET	    /admin/posts
+      #   GET	    /admin/posts/new
+      #   POST	  /admin/posts
+      #   GET	    /admin/posts/1
+      #   GET	    /admin/posts/1/edit
+      #   PUT	    /admin/posts/1
+      #   DELETE  /admin/posts/1
       #
       # If you want to route /posts (without the prefix /admin) to
       # Admin::PostsController, you could use
@@ -473,21 +445,31 @@ module ActionDispatch
       # not use scope. In the last case, the following paths map to
       # PostsController:
       #
-      #   GET	    /admin/photos
-      #   GET	    /admin/photos/new
-      #   POST	  /admin/photos
-      #   GET	    /admin/photos/1
-      #   GET	    /admin/photos/1/edit
-      #   PUT	    /admin/photos/1
-      #   DELETE  /admin/photos/1
+      #   GET	    /admin/posts
+      #   GET	    /admin/posts/new
+      #   POST	  /admin/posts
+      #   GET	    /admin/posts/1
+      #   GET	    /admin/posts/1/edit
+      #   PUT	    /admin/posts/1
+      #   DELETE  /admin/posts/1
       module Scoping
         def initialize(*args) #:nodoc:
           @scope = {}
           super
         end
 
-        # Used to route <tt>/photos</tt> (without the prefix <tt>/admin</tt>)
-        # to Admin::PostsController:
+        # Used to scope a set of routes to particular constraints.
+        #
+        # Take the following route definition as an example:
+        #
+        #   scope :path => ":account_id", :as => "account" do
+        #     resources :projects
+        #   end
+        #
+        # This generates helpers such as +account_projects_path+, just like +resources+ does.
+        # The difference here being that the routes generated are like /rails/projects/2,
+        # rather than /accounts/rails/projects/2.
+        #
         # === Supported options
         # [:module]
         #   If you want to route /posts (without the prefix /admin) to
@@ -588,38 +570,38 @@ module ActionDispatch
         #
         # This generates the following routes:
         #
-        #     admin_posts GET    /admin/posts(.:format)          {:action=>"index", :controller=>"admin/posts"}
-        #     admin_posts POST   /admin/posts(.:format)          {:action=>"create", :controller=>"admin/posts"}
-        #  new_admin_post GET    /admin/posts/new(.:format)      {:action=>"new", :controller=>"admin/posts"}
-        # edit_admin_post GET    /admin/posts/:id/edit(.:format) {:action=>"edit", :controller=>"admin/posts"}
-        #      admin_post GET    /admin/posts/:id(.:format)      {:action=>"show", :controller=>"admin/posts"}
-        #      admin_post PUT    /admin/posts/:id(.:format)      {:action=>"update", :controller=>"admin/posts"}
-        #      admin_post DELETE /admin/posts/:id(.:format)      {:action=>"destroy", :controller=>"admin/posts"}
+        #       admin_posts GET    /admin/posts(.:format)          {:action=>"index", :controller=>"admin/posts"}
+        #       admin_posts POST   /admin/posts(.:format)          {:action=>"create", :controller=>"admin/posts"}
+        #    new_admin_post GET    /admin/posts/new(.:format)      {:action=>"new", :controller=>"admin/posts"}
+        #   edit_admin_post GET    /admin/posts/:id/edit(.:format) {:action=>"edit", :controller=>"admin/posts"}
+        #        admin_post GET    /admin/posts/:id(.:format)      {:action=>"show", :controller=>"admin/posts"}
+        #        admin_post PUT    /admin/posts/:id(.:format)      {:action=>"update", :controller=>"admin/posts"}
+        #        admin_post DELETE /admin/posts/:id(.:format)      {:action=>"destroy", :controller=>"admin/posts"}
         # === Supported options
         #
-        # The +:path+, +:as+, +:module+, +:shallow_path+ and +:shallow_prefix+ all default to the name of the namespace.
+        # The +:path+, +:as+, +:module+, +:shallow_path+ and +:shallow_prefix+ options all default to the name of the namespace.
         #
         # [:path]
         #   The path prefix for the routes.
         #
-        #   namespace :admin, :path => "sekret" do
-        #     resources :posts
-        #   end
+        #     namespace :admin, :path => "sekret" do
+        #       resources :posts
+        #     end
         #
         #   All routes for the above +resources+ will be accessible through +/sekret/posts+, rather than +/admin/posts+
         #
         # [:module]
         #   The namespace for the controllers.
         #
-        #   namespace :admin, :module => "sekret" do
-        #     resources :posts
-        #   end
+        #     namespace :admin, :module => "sekret" do
+        #       resources :posts
+        #     end
         #
         #   The +PostsController+ here should go in the +Sekret+ namespace and so it should be defined like this:
         #
-        #   class Sekret::PostsController < ApplicationController
-        #     # code go here
-        #   end
+        #     class Sekret::PostsController < ApplicationController
+        #       # code go here
+        #     end
         #
         # [:as]
         #   Changes the name used in routing helpers for this namespace.
@@ -638,7 +620,7 @@ module ActionDispatch
                       :shallow_path => path, :shallow_prefix => path }.merge!(options)
           scope(options) { yield }
         end
-        
+
         # === Parameter Restriction
         # Allows you to constrain the nested routes based on a set of rules.
         # For instance, in order to change the routes to allow for a dot character in the +id+ parameter:
@@ -649,7 +631,7 @@ module ActionDispatch
         #
         # Now routes such as +/posts/1+ will no longer be valid, but +/posts/1.1+ will be.
         # The +id+ parameter must match the constraint passed in for this example.
-        # 
+        #
         # You may use this to also resrict other parameters:
         #
         #   resources :posts do
@@ -707,61 +689,61 @@ module ActionDispatch
         end
 
         private
-          def scope_options
+          def scope_options #:nodoc:
             @scope_options ||= private_methods.grep(/^merge_(.+)_scope$/) { $1.to_sym }
           end
 
-          def merge_path_scope(parent, child)
+          def merge_path_scope(parent, child) #:nodoc:
             Mapper.normalize_path("#{parent}/#{child}")
           end
 
-          def merge_shallow_path_scope(parent, child)
+          def merge_shallow_path_scope(parent, child) #:nodoc:
             Mapper.normalize_path("#{parent}/#{child}")
           end
 
-          def merge_as_scope(parent, child)
+          def merge_as_scope(parent, child) #:nodoc:
             parent ? "#{parent}_#{child}" : child
           end
 
-          def merge_shallow_prefix_scope(parent, child)
+          def merge_shallow_prefix_scope(parent, child) #:nodoc:
             parent ? "#{parent}_#{child}" : child
           end
 
-          def merge_module_scope(parent, child)
+          def merge_module_scope(parent, child) #:nodoc:
             parent ? "#{parent}/#{child}" : child
           end
 
-          def merge_controller_scope(parent, child)
+          def merge_controller_scope(parent, child) #:nodoc:
             child
           end
 
-          def merge_path_names_scope(parent, child)
+          def merge_path_names_scope(parent, child) #:nodoc:
             merge_options_scope(parent, child)
           end
 
-          def merge_constraints_scope(parent, child)
+          def merge_constraints_scope(parent, child) #:nodoc:
             merge_options_scope(parent, child)
           end
 
-          def merge_defaults_scope(parent, child)
+          def merge_defaults_scope(parent, child) #:nodoc:
             merge_options_scope(parent, child)
           end
 
-          def merge_blocks_scope(parent, child)
+          def merge_blocks_scope(parent, child) #:nodoc:
             merged = parent ? parent.dup : []
             merged << child if child
             merged
           end
 
-          def merge_options_scope(parent, child)
+          def merge_options_scope(parent, child) #:nodoc:
             (parent || {}).except(*override_keys(child)).merge(child)
           end
 
-          def merge_shallow_scope(parent, child)
+          def merge_shallow_scope(parent, child) #:nodoc:
             child ? true : false
           end
 
-          def override_keys(child)
+          def override_keys(child) #:nodoc:
             child.key?(:only) || child.key?(:except) ? [:only, :except] : []
           end
       end
@@ -969,6 +951,22 @@ module ActionDispatch
         #   GET     /photos/:id/edit
         #   PUT     /photos/:id
         #   DELETE  /photos/:id
+        #
+        # Resources can also be nested infinitely by using this block syntax:
+        #
+        #   resources :photos do
+        #     resources :comments
+        #   end
+        #
+        # This generates the following comments routes:
+        #
+        #   GET     /photos/:id/comments/new
+        #   POST    /photos/:id/comments
+        #   GET     /photos/:id/comments/:id
+        #   GET     /photos/:id/comments/:id/edit
+        #   PUT     /photos/:id/comments/:id
+        #   DELETE  /photos/:id/comments/:id
+        #
         # === Supported options
         # [:path_names]
         #   Allows you to change the paths of the seven default actions.
@@ -977,6 +975,21 @@ module ActionDispatch
         #     resources :posts, :path_names => { :new => "brand_new" }
         #
         #   The above example will now change /posts/new to /posts/brand_new
+        #
+        # [:module]
+        #   Set the module where the controller can be found. Defaults to nothing.
+        #
+        #     resources :posts, :module => "admin"
+        #
+        #   All requests to the posts resources will now go to +Admin::PostsController+.
+        #
+        # [:path]
+        #
+        #  Set a path prefix for this resource.
+        #
+        #     resources :posts, :path => "admin"
+        #
+        #  All actions for this resource will now be at +/admin/posts+.
         def resources(*resources, &block)
           options = resources.extract_options!
 
@@ -1088,6 +1101,7 @@ module ActionDispatch
           end
         end
 
+        # See ActionDispatch::Routing::Mapper::Scoping#namespace
         def namespace(path, options = {})
           if resource_scope?
             nested { super }
@@ -1167,7 +1181,7 @@ module ActionDispatch
             @scope[:scope_level_resource]
           end
 
-          def apply_common_behavior_for(method, resources, options, &block)
+          def apply_common_behavior_for(method, resources, options, &block) #:nodoc:
             if resources.length > 1
               resources.each { |r| send(method, r, options, &block) }
               return true
@@ -1197,23 +1211,23 @@ module ActionDispatch
             false
           end
 
-          def action_options?(options)
+          def action_options?(options) #:nodoc:
             options[:only] || options[:except]
           end
 
-          def scope_action_options?
+          def scope_action_options? #:nodoc:
             @scope[:options].is_a?(Hash) && (@scope[:options][:only] || @scope[:options][:except])
           end
 
-          def scope_action_options
+          def scope_action_options #:nodoc:
             @scope[:options].slice(:only, :except)
           end
 
-          def resource_scope?
+          def resource_scope? #:nodoc:
             [:resource, :resources].include?(@scope[:scope_level])
           end
 
-          def resource_method_scope?
+          def resource_method_scope? #:nodoc:
             [:collection, :member, :new].include?(@scope[:scope_level])
           end
 
@@ -1239,7 +1253,7 @@ module ActionDispatch
             @scope[:scope_level_resource] = old_resource
           end
 
-          def resource_scope(resource)
+          def resource_scope(resource) #:nodoc:
             with_scope_level(resource.is_a?(SingletonResource) ? :resource : :resources, resource) do
               scope(parent_resource.resource_scope) do
                 yield
@@ -1247,30 +1261,30 @@ module ActionDispatch
             end
           end
 
-          def nested_options
+          def nested_options #:nodoc:
             {}.tap do |options|
               options[:as] = parent_resource.member_name
               options[:constraints] = { "#{parent_resource.singular}_id".to_sym => id_constraint } if id_constraint?
             end
           end
 
-          def id_constraint?
+          def id_constraint? #:nodoc:
             @scope[:constraints] && @scope[:constraints][:id].is_a?(Regexp)
           end
 
-          def id_constraint
+          def id_constraint #:nodoc:
             @scope[:constraints][:id]
           end
 
-          def canonical_action?(action, flag)
+          def canonical_action?(action, flag) #:nodoc:
             flag && resource_method_scope? && CANONICAL_ACTIONS.include?(action.to_s)
           end
 
-          def shallow_scoping?
+          def shallow_scoping? #:nodoc:
             shallow? && @scope[:scope_level] == :member
           end
 
-          def path_for_action(action, path)
+          def path_for_action(action, path) #:nodoc:
             prefix = shallow_scoping? ?
               "#{@scope[:shallow_path]}/#{parent_resource.path}/:id" : @scope[:path]
 
@@ -1281,11 +1295,11 @@ module ActionDispatch
             end
           end
 
-          def action_path(name, path = nil)
+          def action_path(name, path = nil) #:nodoc:
             path || @scope[:path_names][name.to_sym] || name.to_s
           end
 
-          def prefix_name_for_action(as, action)
+          def prefix_name_for_action(as, action) #:nodoc:
             if as
               as.to_s
             elsif !canonical_action?(action, @scope[:scope_level])
@@ -1293,12 +1307,14 @@ module ActionDispatch
             end
           end
 
-          def name_for_action(as, action)
+          def name_for_action(as, action) #:nodoc:
             prefix = prefix_name_for_action(as, action)
             prefix = Mapper.normalize_name(prefix) if prefix
             name_prefix = @scope[:as]
 
             if parent_resource
+              return nil if as.nil? && action.nil?
+
               collection_name = parent_resource.collection_name
               member_name = parent_resource.member_name
             end
@@ -1323,7 +1339,7 @@ module ActionDispatch
           end
       end
 
-      module Shorthand
+      module Shorthand #:nodoc:
         def match(*args)
           if args.size == 1 && args.last.is_a?(Hash)
             options  = args.pop
@@ -1338,6 +1354,7 @@ module ActionDispatch
 
       include Base
       include HttpHelpers
+      include Redirection
       include Scoping
       include Resources
       include Shorthand
diff --git a/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb b/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb
index 49e237f8db..82c4fadb50 100644
--- a/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb
+++ b/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb
@@ -99,11 +99,9 @@ module ActionDispatch
         record = extract_record(record_or_hash_or_array)
         record = record.to_model if record.respond_to?(:to_model)
 
-        args = case record_or_hash_or_array
-          when Hash;  [ record_or_hash_or_array ]
-          when Array; record_or_hash_or_array.dup
-          else        [ record_or_hash_or_array ]
-        end
+        args = Array === record_or_hash_or_array ?
+          record_or_hash_or_array.dup :
+          [ record_or_hash_or_array ]
 
         inflection = if options[:action] && options[:action].to_s == "new"
           args.pop
diff --git a/actionpack/lib/action_dispatch/routing/redirection.rb b/actionpack/lib/action_dispatch/routing/redirection.rb
new file mode 100644
index 0000000000..804991ad5f
--- /dev/null
+++ b/actionpack/lib/action_dispatch/routing/redirection.rb
@@ -0,0 +1,110 @@
+require 'action_dispatch/http/request'
+
+module ActionDispatch
+  module Routing
+    module Redirection
+
+      # Redirect any path to another path:
+      #
+      #   match "/stories" => redirect("/posts")
+      #
+      # You can also use interpolation in the supplied redirect argument:
+      #
+      #   match 'docs/:article', :to => redirect('/wiki/%{article}')
+      #
+      # Alternatively you can use one of the other syntaxes:
+      #
+      # The block version of redirect allows for the easy encapsulation of any logic associated with
+      # the redirect in question. Either the params and request are supplied as arguments, or just
+      # params, depending of how many arguments your block accepts. A string is required as a
+      # return value.
+      #
+      #   match 'jokes/:number', :to => redirect do |params, request|
+      #     path = (params[:number].to_i.even? ? "/wheres-the-beef" : "/i-love-lamp")
+      #     "http://#{request.host_with_port}/#{path}"
+      #   end
+      #
+      # The options version of redirect allows you to supply only the parts of the url which need
+      # to change, it also supports interpolation of the path similar to the first example.
+      #
+      #   match 'stores/:name',       :to => redirect(:subdomain => 'stores', :path => '/%{name}')
+      #   match 'stores/:name(*all)', :to => redirect(:subdomain => 'stores', :path => '/%{name}%{all}')
+      #
+      # Finally, an object which responds to call can be supplied to redirect, allowing you to reuse
+      # common redirect routes. The call method must accept two arguments, params and request, and return
+      # a string.
+      #
+      #   match 'accounts/:name' => redirect(SubdomainRedirector.new('api'))
+      #
+      def redirect(*args, &block)
+        options = args.last.is_a?(Hash) ? args.pop : {}
+        status  = options.delete(:status) || 301
+
+        path = args.shift
+
+        path_proc = if path.is_a?(String)
+          proc { |params| (params.empty? || !path.match(/%\{\w*\}/)) ? path : (path % params) }
+        elsif options.any?
+          options_proc(options)
+        elsif path.respond_to?(:call)
+          proc { |params, request| path.call(params, request) }
+        elsif block
+          block
+        else
+          raise ArgumentError, "redirection argument not supported"
+        end
+
+        redirection_proc(status, path_proc)
+      end
+
+      private
+
+        def options_proc(options)
+          proc do |params, request|
+            path = if options[:path].nil?
+              request.path
+            elsif params.empty? || !options[:path].match(/%\{\w*\}/)
+              options.delete(:path)
+            else
+              (options.delete(:path) % params)
+            end
+
+            default_options = {
+              :protocol => request.protocol,
+              :host => request.host,
+              :port => request.optional_port,
+              :path => path,
+              :params => request.query_parameters
+            }
+
+            ActionDispatch::Http::URL.url_for(options.reverse_merge(default_options))
+          end
+        end
+
+        def redirection_proc(status, path_proc)
+          lambda do |env|
+            req = Request.new(env)
+
+            params = [req.symbolized_path_parameters]
+            params << req if path_proc.arity > 1
+
+            uri = URI.parse(path_proc.call(*params))
+            uri.scheme ||= req.scheme
+            uri.host   ||= req.host
+            uri.port   ||= req.port unless req.standard_port?
+
+            body = %(<html><body>You are being <a href="#{ERB::Util.h(uri.to_s)}">redirected</a>.</body></html>)
+
+            headers = {
+              'Location' => uri.to_s,
+              'Content-Type' => 'text/html',
+              'Content-Length' => body.length.to_s
+            }
+
+            [ status, headers, [body] ]
+          end
+        end
+
+    end
+  end
+end
\ No newline at end of file
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index 32f41934f1..03bfe178e5 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -442,12 +442,9 @@ module ActionDispatch
 
           raise_routing_error unless path
 
-          params.reject! {|k,v| !v }
-
           return [path, params.keys] if @extras
 
-          path << "?#{params.to_query}" unless params.empty?
-          path
+          [path, params]
         rescue Rack::Mount::RoutingError
           raise_routing_error
         end
@@ -485,7 +482,8 @@ module ActionDispatch
         Generator.new(options, recall, self, extras).generate
       end
 
-      RESERVED_OPTIONS = [:anchor, :params, :only_path, :host, :protocol, :port, :trailing_slash, :script_name]
+      RESERVED_OPTIONS = [:host, :protocol, :port, :subdomain, :domain, :tld_length,
+                          :trailing_slash, :anchor, :params, :only_path, :script_name]
 
       def _generate_prefix(options = {})
         nil
@@ -497,32 +495,24 @@ module ActionDispatch
 
         handle_positional_args(options)
 
-        rewritten_url = ""
-
-        path_segments = options.delete(:_path_segments)
-        unless options[:only_path]
-          rewritten_url << (options[:protocol] || "http")
-          rewritten_url << "://" unless rewritten_url.match("://")
-          rewritten_url << rewrite_authentication(options)
-
-          raise "Missing host to link to! Please provide :host parameter or set default_url_options[:host]" unless options[:host]
-
-          rewritten_url << options[:host]
-          rewritten_url << ":#{options.delete(:port)}" if options.key?(:port)
-        end
+        user, password = extract_authentication(options)
+        path_segments  = options.delete(:_path_segments)
+        script_name    = options.delete(:script_name)
 
-        script_name = options.delete(:script_name)
         path = (script_name.blank? ? _generate_prefix(options) : script_name.chomp('/')).to_s
 
         path_options = options.except(*RESERVED_OPTIONS)
         path_options = yield(path_options) if block_given?
-        path << generate(path_options, path_segments || {})
 
-        # ROUTES TODO: This can be called directly, so script_name should probably be set in the routes
-        rewritten_url << (options[:trailing_slash] ? path.sub(/\?|\z/) { "/" + $& } : path)
-        rewritten_url << "##{Rack::Mount::Utils.escape_uri(options[:anchor].to_param.to_s)}" if options[:anchor]
+        path_addition, params = generate(path_options, path_segments || {})
+        path << path_addition
 
-        rewritten_url
+        ActionDispatch::Http::URL.url_for(options.merge({
+          :path => path,
+          :params => params,
+          :user => user,
+          :password => password
+        }))
       end
 
       def call(env)
@@ -562,6 +552,15 @@ module ActionDispatch
       end
 
       private
+
+        def extract_authentication(options)
+          if options[:user] && options[:password]
+            [options.delete(:user), options.delete(:password)]
+          else
+            nil
+          end
+        end
+
         def handle_positional_args(options)
           return unless args = options.delete(:_positional_args)
 
@@ -572,13 +571,6 @@ module ActionDispatch
           options.merge!(Hash[args.zip(keys).map { |v, k| [k, v] }])
         end
 
-        def rewrite_authentication(options)
-          if options[:user] && options[:password]
-            "#{Rack::Utils.escape(options.delete(:user))}:#{Rack::Utils.escape(options.delete(:password))}@"
-          else
-            ""
-          end
-        end
     end
   end
 end
diff --git a/actionpack/lib/action_dispatch/routing/url_for.rb b/actionpack/lib/action_dispatch/routing/url_for.rb
index bfdea41f60..d4db78a25a 100644
--- a/actionpack/lib/action_dispatch/routing/url_for.rb
+++ b/actionpack/lib/action_dispatch/routing/url_for.rb
@@ -115,6 +115,13 @@ module ActionDispatch
       # * <tt>:host</tt> - Specifies the host the link should be targeted at.
       #   If <tt>:only_path</tt> is false, this option must be
       #   provided either explicitly, or via +default_url_options+.
+      # * <tt>:subdomain</tt> - Specifies the subdomain of the link, using the +tld_length+
+      #   to split the domain from the host.
+      # * <tt>:domain</tt> - Specifies the domain of the link, using the +tld_length+
+      #   to split the subdomain from the host.
+      # * <tt>:tld_length</tt> - Number of labels the TLD id composed of, only used if
+      #   <tt>:subdomain</tt> or <tt>:domain</tt> are supplied. Defaults to
+      #   <tt>ActionDispatch::Http::URL.tld_length</tt>, which in turn defaults to 1.
       # * <tt>:port</tt> - Optionally specify the port to connect to.
       # * <tt>:anchor</tt> - An anchor name to be appended to the path.
       # * <tt>:trailing_slash</tt> - If true, adds a trailing slash, as in "/archive/2009/"
diff --git a/actionpack/lib/action_dispatch/testing/integration.rb b/actionpack/lib/action_dispatch/testing/integration.rb
index fee8cad9f5..5c6416a19e 100644
--- a/actionpack/lib/action_dispatch/testing/integration.rb
+++ b/actionpack/lib/action_dispatch/testing/integration.rb
@@ -235,9 +235,7 @@ module ActionDispatch
       # Set the host name to use in the next request.
       #
       #   session.host! "www.example.com"
-      def host!(name)
-        @host = name
-      end
+      alias :host! :host=
 
       private
         def _mock_session
@@ -363,6 +361,10 @@ module ActionDispatch
         integration_session.url_options
       end
 
+      def respond_to?(method, include_private = false)
+        integration_session.respond_to?(method, include_private) || super
+      end
+
       # Delegate unhandled messages to the current session instance.
       def method_missing(sym, *args, &block)
         reset! unless integration_session
diff --git a/actionpack/lib/action_view/base.rb b/actionpack/lib/action_view/base.rb
index 1beae37af3..92ff3380b0 100644
--- a/actionpack/lib/action_view/base.rb
+++ b/actionpack/lib/action_view/base.rb
@@ -76,8 +76,8 @@ module ActionView #:nodoc:
   #
   # === Template caching
   #
-  # By default, Rails will compile each template to a method in order to render it. When you alter a template, Rails will
-  # check the file's modification time and recompile it.
+  # By default, Rails will compile each template to a method in order to render it. When you alter a template,
+  # Rails will check the file's modification time and recompile it in development mode.
   #
   # == Builder
   #
@@ -172,6 +172,14 @@ module ActionView #:nodoc:
     class << self
       delegate :erb_trim_mode=, :to => 'ActionView::Template::Handlers::ERB'
       delegate :logger, :to => 'ActionController::Base', :allow_nil => true
+
+      def cache_template_loading
+        ActionView::Resolver.caching?
+      end
+
+      def cache_template_loading=(value)
+        ActionView::Resolver.caching = value
+      end
     end
 
     attr_accessor :_template
diff --git a/actionpack/lib/action_view/helpers/asset_tag_helpers/asset_include_tag.rb b/actionpack/lib/action_view/helpers/asset_tag_helpers/asset_include_tag.rb
index 15f8e10b7f..e52797042f 100644
--- a/actionpack/lib/action_view/helpers/asset_tag_helpers/asset_include_tag.rb
+++ b/actionpack/lib/action_view/helpers/asset_tag_helpers/asset_include_tag.rb
@@ -79,7 +79,6 @@ module ActionView
             sources.each do |source|
               asset_file_path!(path_to_asset(source, false))
             end
-            return sources
           end
 
           def collect_asset_files(*path)
diff --git a/actionpack/lib/action_view/helpers/form_helper.rb b/actionpack/lib/action_view/helpers/form_helper.rb
index 8c300ec745..6f0e2c99ba 100644
--- a/actionpack/lib/action_view/helpers/form_helper.rb
+++ b/actionpack/lib/action_view/helpers/form_helper.rb
@@ -2,7 +2,7 @@ require 'cgi'
 require 'action_view/helpers/date_helper'
 require 'action_view/helpers/tag_helper'
 require 'action_view/helpers/form_tag_helper'
-require 'active_support/core_ext/class/inheritable_attributes'
+require 'active_support/core_ext/class/attribute'
 require 'active_support/core_ext/hash/slice'
 require 'active_support/core_ext/object/blank'
 require 'active_support/core_ext/string/output_safety'
@@ -1115,9 +1115,9 @@ module ActionView
       include InstanceTagMethods
     end
 
-    class FormBuilder #:nodoc:
+    class FormBuilder
       # The methods which wrap a form helper call.
-      class_inheritable_accessor :field_helpers
+      class_attribute :field_helpers
       self.field_helpers = (FormHelper.instance_method_names - ['form_for'])
 
       attr_accessor :object_name, :object, :options
diff --git a/actionpack/lib/action_view/helpers/form_tag_helper.rb b/actionpack/lib/action_view/helpers/form_tag_helper.rb
index 92645f5cf9..9500e85e8b 100644
--- a/actionpack/lib/action_view/helpers/form_tag_helper.rb
+++ b/actionpack/lib/action_view/helpers/form_tag_helper.rb
@@ -39,7 +39,7 @@ module ActionView
       #   form_tag('/upload', :multipart => true)
       #   # => <form action="/upload" method="post" enctype="multipart/form-data">
       #
-      #   <%= form_tag('/posts')do -%>
+      #   <%= form_tag('/posts') do -%>
       #     <div><%= submit_tag 'Save' %></div>
       #   <% end -%>
       #   # => <form action="/posts" method="post"><div><input type="submit" name="submit" value="Save" /></div></form>
@@ -68,7 +68,7 @@ module ActionView
       # * Any other key creates standard HTML attributes for the tag.
       #
       # ==== Examples
-      #   select_tag "people", options_from_collection_for_select(@people, "name", "id")
+      #   select_tag "people", options_from_collection_for_select(@people, "id", "name")
       #   # <select id="people" name="people"><option value="1">David</option></select>
       #
       #   select_tag "people", "<option>David</option>"
@@ -112,6 +112,7 @@ module ActionView
       # * <tt>:disabled</tt> - If set to true, the user will not be able to use this input.
       # * <tt>:size</tt> - The number of visible characters that will fit in the input.
       # * <tt>:maxlength</tt> - The maximum number of characters that the browser will allow the user to enter.
+      # * <tt>:placeholder</tt> - The text contained in the field by default which is removed when the field receives focus.
       # * Any other key creates standard HTML attributes for the tag.
       #
       # ==== Examples
@@ -121,6 +122,9 @@ module ActionView
       #   text_field_tag 'query', 'Enter your search query here'
       #   # => <input id="query" name="query" type="text" value="Enter your search query here" />
       #
+      #   text_field_tag 'search', nil, :placeholder => 'Enter search term...'
+      #   # => <input id="search" name="search" placeholder="Enter search term..." type="text" />
+      #
       #   text_field_tag 'request', nil, :class => 'special_input'
       #   # => <input class="special_input" id="request" name="request" type="text" />
       #
diff --git a/actionpack/lib/action_view/helpers/number_helper.rb b/actionpack/lib/action_view/helpers/number_helper.rb
index a9400c347f..26f8dce3c3 100644
--- a/actionpack/lib/action_view/helpers/number_helper.rb
+++ b/actionpack/lib/action_view/helpers/number_helper.rb
@@ -270,12 +270,13 @@ module ActionView
             digits, rounded_number = 1, 0
           else
             digits = (Math.log10(number.abs) + 1).floor
-            rounded_number = BigDecimal.new((number / 10 ** (digits - precision)).to_s).round.to_f * 10 ** (digits - precision)
+            rounded_number = (BigDecimal.new(number.to_s) / BigDecimal.new((10 ** (digits - precision)).to_f.to_s)).round.to_f * 10 ** (digits - precision)
+            digits = (Math.log10(rounded_number.abs) + 1).floor # After rounding, the number of digits may have changed
           end
           precision -= digits
           precision = precision > 0 ? precision : 0  #don't let it be negative
         else
-          rounded_number = BigDecimal.new((number * (10 ** precision)).to_s).round.to_f / 10 ** precision
+          rounded_number = BigDecimal.new(number.to_s).round(precision).to_f
         end
         formatted_number = number_with_delimiter("%01.#{precision}f" % rounded_number, options)
         if strip_insignificant_zeros
diff --git a/actionpack/lib/action_view/helpers/translation_helper.rb b/actionpack/lib/action_view/helpers/translation_helper.rb
index 8574ca6595..e7ec1df2c8 100644
--- a/actionpack/lib/action_view/helpers/translation_helper.rb
+++ b/actionpack/lib/action_view/helpers/translation_helper.rb
@@ -1,13 +1,33 @@
 require 'action_view/helpers/tag_helper'
+require 'i18n/exceptions'
+
+module I18n
+  class ExceptionHandler
+    include Module.new {
+      def call(exception, locale, key, options)
+        exception.is_a?(MissingTranslationData) ? super.html_safe : super
+      end
+    }
+  end
+end
 
 module ActionView
   # = Action View Translation Helpers
   module Helpers
     module TranslationHelper
       # Delegates to I18n#translate but also performs three additional functions.
-      # First, it'll catch MissingTranslationData exceptions and turn them into
-      # inline spans that contains the missing key, such that you can see in a
-      # view what is missing where.
+      #
+      # First, it'll pass the :rescue_format => :html option to I18n so that any caught
+      # MissingTranslationData exceptions will be turned into inline spans that
+      #
+      #   * have a "translation-missing" class set,
+      #   * contain the missing key as a title attribute and
+      #   * a titleized version of the last key segment as a text.
+      #
+      # E.g. the value returned for a missing translation key :"blog.post.title" will be
+      # <span class="translation_missing" title="translation missing: blog.post.title">Title</span>.
+      # This way your views will display rather reasonableful strings but it will still
+      # be easy to spot missing translations.
       #
       # Second, it'll scope the key by the current partial if the key starts
       # with a period. So if you call <tt>translate(".foo")</tt> from the
@@ -24,15 +44,13 @@ module ActionView
       # naming convention helps to identify translations that include HTML tags so that
       # you know what kind of output to expect when you call translate in a template.
       def translate(key, options = {})
-        translation = I18n.translate(scope_key_by_partial(key), options.merge!(:raise => true))
+        options.merge!(:rescue_format => :html) unless options.key?(:rescue_format)
+        translation = I18n.translate(scope_key_by_partial(key), options)
         if html_safe_translation_key?(key) && translation.respond_to?(:html_safe)
           translation.html_safe
         else
           translation
         end
-      rescue I18n::MissingTranslationData => e
-        keys = I18n.normalize_keys(e.locale, e.key, e.options[:scope])
-        content_tag('span', keys.join(', '), :class => 'translation_missing')
       end
       alias :t :translate
 
diff --git a/actionpack/lib/action_view/lookup_context.rb b/actionpack/lib/action_view/lookup_context.rb
index 27f94a73a6..d524c68450 100644
--- a/actionpack/lib/action_view/lookup_context.rb
+++ b/actionpack/lib/action_view/lookup_context.rb
@@ -109,7 +109,7 @@ module ActionView
 
       def args_for_lookup(name, prefix, partial, keys) #:nodoc:
         name, prefix = normalize_name(name, prefix)
-        [name, prefix, partial || false, @details, keys, details_key]
+        [name, prefix, partial || false, @details, details_key, keys]
       end
 
       # Support legacy foo.erb names even though we now ignore .erb
diff --git a/actionpack/lib/action_view/partials.rb b/actionpack/lib/action_view/partials.rb
index 844c3e9572..cd3f130dc4 100644
--- a/actionpack/lib/action_view/partials.rb
+++ b/actionpack/lib/action_view/partials.rb
@@ -75,6 +75,11 @@ module ActionView
   #
   #   <%= render :partial => "ad", :collection => @advertisements, :spacer_template => "ad_divider" %>
   #
+  # If the given <tt>:collection</tt> is nil or empty, <tt>render</tt> will return nil. This will allow you
+  # to specify a text which will displayed instead by using this form:
+  #
+  #   <%= render(:partial => "ad", :collection => @advertisements) || "There's no ad to be displayed" %>
+  #
   # NOTE: Due to backwards compatibility concerns, the collection can't be one of hashes. Normally you'd also
   # just keep domain objects, like Active Records, in there.
   #
diff --git a/actionpack/lib/action_view/path_set.rb b/actionpack/lib/action_view/path_set.rb
index dc26d75ff3..fa35120a0d 100644
--- a/actionpack/lib/action_view/path_set.rb
+++ b/actionpack/lib/action_view/path_set.rb
@@ -10,10 +10,8 @@ module ActionView #:nodoc:
       METHOD
     end
 
-    def find(path, prefix = nil, partial = false, details = {}, keys = [], key = nil)
-      template = find_all(path, prefix, partial, details, keys, key).first
-      raise MissingTemplate.new(self, "#{prefix}/#{path}", details, partial) unless template
-      template
+    def find(*args)
+      find_all(*args).first || raise(MissingTemplate.new(self, "#{args[1]}/#{args[0]}", args[3], args[2]))
     end
 
     def find_all(*args)
diff --git a/actionpack/lib/action_view/railtie.rb b/actionpack/lib/action_view/railtie.rb
index 71cd1a788a..501ec07b09 100644
--- a/actionpack/lib/action_view/railtie.rb
+++ b/actionpack/lib/action_view/railtie.rb
@@ -35,5 +35,13 @@ module ActionView
         end
       end
     end
+
+    initializer "action_view.caching" do |app|
+      ActiveSupport.on_load(:action_view) do
+        if app.config.action_view.cache_template_loading.nil?
+          ActionView::Resolver.caching = app.config.cache_classes
+        end
+      end
+    end
   end
-end
\ No newline at end of file
+end
diff --git a/actionpack/lib/action_view/renderer/template_renderer.rb b/actionpack/lib/action_view/renderer/template_renderer.rb
index 6912acee31..ece3f621b6 100644
--- a/actionpack/lib/action_view/renderer/template_renderer.rb
+++ b/actionpack/lib/action_view/renderer/template_renderer.rb
@@ -45,7 +45,7 @@ module ActionView
       elsif options.key?(:file)
         with_fallbacks { find_template(options[:file], options[:prefix], false, keys) }
       elsif options.key?(:inline)
-        handler = Template.handler_class_for_extension(options[:type] || "erb")
+        handler = Template.handler_for_extension(options[:type] || "erb")
         Template.new(options[:inline], "inline template", handler, :locals => keys)
       elsif options.key?(:template)
         options[:template].respond_to?(:render) ?
diff --git a/actionpack/lib/action_view/template.rb b/actionpack/lib/action_view/template.rb
index 6c6d659246..0d8373ef14 100644
--- a/actionpack/lib/action_view/template.rb
+++ b/actionpack/lib/action_view/template.rb
@@ -184,6 +184,11 @@ module ActionView
       end
     end
 
+    # Used to store template data by template handlers.
+    def data
+      @data ||= {}
+    end
+
     def inspect
       @inspect ||=
         if defined?(Rails.root)
@@ -270,7 +275,7 @@ module ActionView
         end
 
         arity = @handler.respond_to?(:arity) ? @handler.arity : @handler.method(:call).arity
-        code  = arity == 1 ? @handler.call(self) : @handler.call(self, view)
+        code  = arity.abs == 1 ? @handler.call(self) : @handler.call(self, view)
 
         # Make sure that the resulting String to be evalled is in the
         # encoding of the code
diff --git a/actionpack/lib/action_view/template/handlers.rb b/actionpack/lib/action_view/template/handlers.rb
index 60347e2a95..4438199497 100644
--- a/actionpack/lib/action_view/template/handlers.rb
+++ b/actionpack/lib/action_view/template/handlers.rb
@@ -44,7 +44,13 @@ module ActionView #:nodoc:
       end
 
       def handler_class_for_extension(extension)
-        (extension && registered_template_handler(extension.to_sym)) || @@default_template_handlers
+        ActiveSupport::Deprecation.warn "handler_class_for_extension is deprecated. " <<
+          "Please use handler_for_extension instead", caller
+        handler_for_extension(extension)
+      end
+
+      def handler_for_extension(extension)
+        registered_template_handler(extension) || @@default_template_handlers
       end
     end
   end
diff --git a/actionpack/lib/action_view/template/resolver.rb b/actionpack/lib/action_view/template/resolver.rb
index 7707dbcf98..0dccc99d14 100644
--- a/actionpack/lib/action_view/template/resolver.rb
+++ b/actionpack/lib/action_view/template/resolver.rb
@@ -5,6 +5,13 @@ require "action_view/template"
 module ActionView
   # = Action View Resolver
   class Resolver
+    cattr_accessor :caching
+    self.caching = true
+
+    class << self
+      alias :caching? :caching
+    end
+
     def initialize
       @cached = Hash.new { |h1,k1| h1[k1] = Hash.new { |h2,k2|
         h2[k2] = Hash.new { |h3,k3| h3[k3] = Hash.new { |h4,k4| h4[k4] = {} } } } }
@@ -15,7 +22,7 @@ module ActionView
     end
 
     # Normalizes the arguments and passes it on to find_template.
-    def find_all(name, prefix=nil, partial=false, details={}, locals=[], key=nil)
+    def find_all(name, prefix=nil, partial=false, details={}, key=nil, locals=[])
       cached(key, [name, prefix, partial], details, locals) do
         find_templates(name, prefix, partial, details)
       end
@@ -23,9 +30,7 @@ module ActionView
 
   private
 
-    def caching?
-      @caching ||= !defined?(Rails.application) || Rails.application.config.cache_classes
-    end
+    delegate :caching?, :to => "self.class"
 
     # This is what child classes implement. No defaults are needed
     # because Resolver guarantees that the arguments are present and
@@ -129,7 +134,7 @@ module ActionView
     def extract_handler_and_format(path, default_formats)
       pieces = File.basename(path).split(".")
       pieces.shift
-      handler = Template.handler_class_for_extension(pieces.pop)
+      handler = Template.handler_for_extension(pieces.pop)
       format  = pieces.last && Mime[pieces.last]
       [handler, format]
     end