Merge branch 'master' into loofah

Conflicts:
	actionpack/CHANGELOG.md
	actionpack/test/controller/integration_test.rb
	actionview/CHANGELOG.md

15 files changed, 194 insertions, 154 deletions

diff --git a/actionview/lib/action_view/base.rb b/actionview/lib/action_view/base.rb
index 900f96255e..86c55ffb51 100644
--- a/actionview/lib/action_view/base.rb
+++ b/actionview/lib/action_view/base.rb
@@ -66,15 +66,6 @@ module ActionView #:nodoc:
   #   Headline: <%= headline %>
   #   First name: <%= person.first_name %>
   #
-  # If you need to find out whether a certain local variable has been assigned a value in a particular render call,
-  # you need to use the following pattern:
-  #
-  #   <% if local_assigns.has_key? :headline %>
-  #     Headline: <%= headline %>
-  #   <% end %>
-  #
-  # Testing using <tt>defined? headline</tt> will not work. This is an implementation restriction.
-  #
   # === Template caching
   #
   # By default, Rails will compile each template to a method in order to render it. When you alter a template,
diff --git a/actionview/lib/action_view/dependency_tracker.rb b/actionview/lib/action_view/dependency_tracker.rb
index 0ccf2515c5..e34bdd4a46 100644
--- a/actionview/lib/action_view/dependency_tracker.rb
+++ b/actionview/lib/action_view/dependency_tracker.rb
@@ -53,6 +53,12 @@ module ActionView
         \s*                          # followed by optional spaces
       /x
 
+      # Part of any hash containing the :layout key
+      LAYOUT_HASH_KEY = /
+        (?:\blayout:|:layout\s*=>)   # layout key in either old or new style hash syntax
+        \s*                          # followed by optional spaces
+      /x
+
       # Matches:
       #   partial: "comments/comment", collection: @all_comments => "comments/comment"
       #   (object: @single_comment, partial: "comments/comment") => "comments/comment"
@@ -65,9 +71,9 @@ module ActionView
       #    topics          => "topics/topic"
       #   (message.topics) => "topics/topic"
       RENDER_ARGUMENTS = /\A
-        (?:\s*\(?\s*)                             # optional opening paren surrounded by spaces
-        (?:.*?#{PARTIAL_HASH_KEY})?               # optional hash, up to the partial key declaration
-        (?:#{STRING}|#{VARIABLE_OR_METHOD_CHAIN}) # finally, the dependency name of interest
+        (?:\s*\(?\s*)                                  # optional opening paren surrounded by spaces
+        (?:.*?#{PARTIAL_HASH_KEY}|#{LAYOUT_HASH_KEY})? # optional hash, up to the partial or layout key declaration
+        (?:#{STRING}|#{VARIABLE_OR_METHOD_CHAIN})      # finally, the dependency name of interest
       /xm
 
       def self.call(name, template)
@@ -85,8 +91,8 @@ module ActionView
       attr_reader :name, :template
       private :name, :template
 
-      private
 
+      private
         def source
           template.source
         end
diff --git a/actionview/lib/action_view/digestor.rb b/actionview/lib/action_view/digestor.rb
index 72d79735ae..1f103786cb 100644
--- a/actionview/lib/action_view/digestor.rb
+++ b/actionview/lib/action_view/digestor.rb
@@ -60,7 +60,7 @@ module ActionView
 
     def digest
       Digest::MD5.hexdigest("#{source}-#{dependency_digest}").tap do |digest|
-        logger.try :info, "  Cache digest for #{template.inspect}: #{digest}"
+        logger.try :debug, "  Cache digest for #{template.inspect}: #{digest}"
       end
     rescue ActionView::MissingTemplate
       logger.try :error, "  Couldn't find template for digesting: #{name}"
diff --git a/actionview/lib/action_view/helpers/asset_url_helper.rb b/actionview/lib/action_view/helpers/asset_url_helper.rb
index 469f7c16bd..9e8d005ec7 100644
--- a/actionview/lib/action_view/helpers/asset_url_helper.rb
+++ b/actionview/lib/action_view/helpers/asset_url_helper.rb
@@ -203,7 +203,6 @@ module ActionView
         request = self.request if respond_to?(:request)
         host = options[:host]
         host ||= config.asset_host if defined? config.asset_host
-        host ||= request.base_url if request && options[:protocol] == :request
 
         if host.respond_to?(:call)
           arity = host.respond_to?(:arity) ? host.arity : host.method(:call).arity
@@ -214,6 +213,7 @@ module ActionView
           host = host % (Zlib.crc32(source) % 4)
         end
 
+        host ||= request.base_url if request && options[:protocol] == :request
         return unless host
 
         if host =~ URI_REGEXP
diff --git a/actionview/lib/action_view/helpers/form_options_helper.rb b/actionview/lib/action_view/helpers/form_options_helper.rb
index 48f42947db..8ade7c6a74 100644
--- a/actionview/lib/action_view/helpers/form_options_helper.rb
+++ b/actionview/lib/action_view/helpers/form_options_helper.rb
@@ -14,81 +14,81 @@ module ActionView
     #
     # * <tt>:include_blank</tt> - set to true or a prompt string if the first option element of the select element is a blank. Useful if there is not a default value required for the select element.
     #
-    #   select("post", "category", Post::CATEGORIES, {include_blank: true})
+    #     select("post", "category", Post::CATEGORIES, {include_blank: true})
     #
-    # could become:
+    #   could become:
     #
-    #   <select name="post[category]">
-    #     <option></option>
-    #     <option>joke</option>
-    #     <option>poem</option>
-    #   </select>
+    #     <select name="post[category]">
+    #       <option></option>
+    #       <option>joke</option>
+    #       <option>poem</option>
+    #     </select>
     #
-    # Another common case is a select tag for a <tt>belongs_to</tt>-associated object.
+    #   Another common case is a select tag for a <tt>belongs_to</tt>-associated object.
     #
-    # Example with @post.person_id => 2:
+    #   Example with <tt>@post.person_id => 2</tt>:
     #
-    #   select("post", "person_id", Person.all.collect {|p| [ p.name, p.id ] }, {include_blank: 'None'})
+    #     select("post", "person_id", Person.all.collect {|p| [ p.name, p.id ] }, {include_blank: 'None'})
     #
-    # could become:
+    #   could become:
     #
-    #   <select name="post[person_id]">
-    #     <option value="">None</option>
-    #     <option value="1">David</option>
-    #     <option value="2" selected="selected">Sam</option>
-    #     <option value="3">Tobias</option>
-    #   </select>
+    #     <select name="post[person_id]">
+    #       <option value="">None</option>
+    #       <option value="1">David</option>
+    #       <option value="2" selected="selected">Sam</option>
+    #       <option value="3">Tobias</option>
+    #     </select>
     #
     # * <tt>:prompt</tt> - set to true or a prompt string. When the select element doesn't have a value yet, this prepends an option with a generic prompt -- "Please select" -- or the given prompt string.
     #
-    #   select("post", "person_id", Person.all.collect {|p| [ p.name, p.id ] }, {prompt: 'Select Person'})
+    #     select("post", "person_id", Person.all.collect {|p| [ p.name, p.id ] }, {prompt: 'Select Person'})
     #
-    # could become:
+    #   could become:
     #
-    #   <select name="post[person_id]">
-    #     <option value="">Select Person</option>
-    #     <option value="1">David</option>
-    #     <option value="2">Sam</option>
-    #     <option value="3">Tobias</option>
-    #   </select>
+    #     <select name="post[person_id]">
+    #       <option value="">Select Person</option>
+    #       <option value="1">David</option>
+    #       <option value="2">Sam</option>
+    #       <option value="3">Tobias</option>
+    #     </select>
     #
-    # Like the other form helpers, +select+ can accept an <tt>:index</tt> option to manually set the ID used in the resulting output. Unlike other helpers, +select+ expects this
-    # option to be in the +html_options+ parameter.
+    # * <tt>:index</tt> - like the other form helpers, +select+ can accept an <tt>:index</tt> option to manually set the ID used in the resulting output. Unlike other helpers, +select+ expects this
+    #   option to be in the +html_options+ parameter.
     #
-    #   select("album[]", "genre", %w[rap rock country], {}, { index: nil })
+    #     select("album[]", "genre", %w[rap rock country], {}, { index: nil })
     #
-    # becomes:
+    #   becomes:
     #
-    #   <select name="album[][genre]" id="album__genre">
-    #     <option value="rap">rap</option>
-    #     <option value="rock">rock</option>
-    #     <option value="country">country</option>
-    #   </select>
+    #     <select name="album[][genre]" id="album__genre">
+    #       <option value="rap">rap</option>
+    #       <option value="rock">rock</option>
+    #       <option value="country">country</option>
+    #     </select>
     #
     # * <tt>:disabled</tt> - can be a single value or an array of values that will be disabled options in the final output.
     #
-    #   select("post", "category", Post::CATEGORIES, {disabled: 'restricted'})
+    #     select("post", "category", Post::CATEGORIES, {disabled: 'restricted'})
     #
-    # could become:
+    #   could become:
     #
-    #   <select name="post[category]">
-    #     <option></option>
-    #     <option>joke</option>
-    #     <option>poem</option>
-    #     <option disabled="disabled">restricted</option>
-    #   </select>
+    #     <select name="post[category]">
+    #       <option></option>
+    #       <option>joke</option>
+    #       <option>poem</option>
+    #       <option disabled="disabled">restricted</option>
+    #     </select>
     #
-    # When used with the <tt>collection_select</tt> helper, <tt>:disabled</tt> can also be a Proc that identifies those options that should be disabled.
+    #   When used with the <tt>collection_select</tt> helper, <tt>:disabled</tt> can also be a Proc that identifies those options that should be disabled.
     #
-    #   collection_select(:post, :category_id, Category.all, :id, :name, {disabled: lambda{|category| category.archived? }})
+    #     collection_select(:post, :category_id, Category.all, :id, :name, {disabled: lambda{|category| category.archived? }})
     #
-    # If the categories "2008 stuff" and "Christmas" return true when the method <tt>archived?</tt> is called, this would return:
-    #   <select name="post[category_id]">
-    #     <option value="1" disabled="disabled">2008 stuff</option>
-    #     <option value="2" disabled="disabled">Christmas</option>
-    #     <option value="3">Jokes</option>
-    #     <option value="4">Poems</option>
-    #   </select>
+    #   If the categories "2008 stuff" and "Christmas" return true when the method <tt>archived?</tt> is called, this would return:
+    #     <select name="post[category_id]">
+    #       <option value="1" disabled="disabled">2008 stuff</option>
+    #       <option value="2" disabled="disabled">Christmas</option>
+    #       <option value="3">Jokes</option>
+    #       <option value="4">Poems</option>
+    #     </select>
     #
     module FormOptionsHelper
       # ERB::Util can mask some helpers like textilize. Make sure to include them.
@@ -152,11 +152,9 @@ module ActionView
       # To prevent this the helper generates an auxiliary hidden field before
       # every multiple select. The hidden field has the same name as multiple select and blank value.
       #
-      # This way, the client either sends only the hidden field (representing
-      # the deselected multiple select box), or both fields. Since the HTML specification
-      # says key/value pairs have to be sent in the same order they appear in the
-      # form, and parameters extraction gets the last occurrence of any repeated
-      # key in the query string, that works for ordinary forms.
+      # <b>Note:</b> The client either sends only the hidden field (representing
+      # the deselected multiple select box), or both fields. This means that the resulting array
+      # always contains a blank string.
       #
       # In case if you don't want the helper to generate this hidden field you can specify
       # <tt>include_hidden: false</tt> option.
@@ -463,21 +461,7 @@ module ActionView
       end
 
       # Returns a string of <tt><option></tt> tags, like <tt>options_for_select</tt>, but
-      # wraps them with <tt><optgroup></tt> tags.
-      #
-      # Parameters:
-      # * +grouped_options+ - Accepts a nested array or hash of strings. The first value serves as the
-      #   <tt><optgroup></tt> label while the second value must be an array of options. The second value can be a
-      #   nested array of text-value pairs. See <tt>options_for_select</tt> for more info.
-      #    Ex. ["North America",[["United States","US"],["Canada","CA"]]]
-      # * +selected_key+ - A value equal to the +value+ attribute for one of the <tt><option></tt> tags,
-      #   which will have the +selected+ attribute set. Note: It is possible for this value to match multiple options
-      #   as you might have the same option in multiple groups. Each will then get <tt>selected="selected"</tt>.
-      #
-      # Options:
-      # * <tt>:prompt</tt> - set to true or a prompt string. When the select element doesn't have a value yet, this
-      #   prepends an option with a generic prompt - "Please select" - or the given prompt string.
-      # * <tt>:divider</tt> - the divider for the options groups.
+      # wraps them with <tt><optgroup></tt> tags:
       #
       #   grouped_options = [
       #    ['North America',
@@ -504,22 +488,36 @@ module ActionView
       #     <option value="France">France</option>
       #   </optgroup>
       #
-      #   grouped_options = [
-      #     [['United States','US'], 'Canada'],
-      #     ['Denmark','Germany','France']
-      #   ]
-      #   grouped_options_for_select(grouped_options, nil, divider: '---------')
+      # Parameters:
+      # * +grouped_options+ - Accepts a nested array or hash of strings. The first value serves as the
+      #   <tt><optgroup></tt> label while the second value must be an array of options. The second value can be a
+      #   nested array of text-value pairs. See <tt>options_for_select</tt> for more info.
+      #    Ex. ["North America",[["United States","US"],["Canada","CA"]]]
+      # * +selected_key+ - A value equal to the +value+ attribute for one of the <tt><option></tt> tags,
+      #   which will have the +selected+ attribute set. Note: It is possible for this value to match multiple options
+      #   as you might have the same option in multiple groups. Each will then get <tt>selected="selected"</tt>.
       #
-      # Possible output:
-      #   <optgroup label="---------">
-      #     <option value="US">United States</option>
-      #     <option value="Canada">Canada</option>
-      #   </optgroup>
-      #   <optgroup label="---------">
-      #     <option value="Denmark">Denmark</option>
-      #     <option value="Germany">Germany</option>
-      #     <option value="France">France</option>
-      #   </optgroup>
+      # Options:
+      # * <tt>:prompt</tt> - set to true or a prompt string. When the select element doesn't have a value yet, this
+      #   prepends an option with a generic prompt - "Please select" - or the given prompt string.
+      # * <tt>:divider</tt> - the divider for the options groups.
+      #
+      #     grouped_options = [
+      #       [['United States','US'], 'Canada'],
+      #       ['Denmark','Germany','France']
+      #     ]
+      #     grouped_options_for_select(grouped_options, nil, divider: '---------')
+      #
+      #   Possible output:
+      #     <optgroup label="---------">
+      #       <option value="US">United States</option>
+      #       <option value="Canada">Canada</option>
+      #     </optgroup>
+      #     <optgroup label="---------">
+      #       <option value="Denmark">Denmark</option>
+      #       <option value="Germany">Germany</option>
+      #       <option value="France">France</option>
+      #     </optgroup>
       #
       # <b>Note:</b> Only the <tt><optgroup></tt> and <tt><option></tt> tags are returned, so you still have to
       # wrap the output in an appropriate <tt><select></tt> tag.
diff --git a/actionview/lib/action_view/helpers/output_safety_helper.rb b/actionview/lib/action_view/helpers/output_safety_helper.rb
index b0d9c7c7f9..f03362d0f5 100644
--- a/actionview/lib/action_view/helpers/output_safety_helper.rb
+++ b/actionview/lib/action_view/helpers/output_safety_helper.rb
@@ -17,7 +17,7 @@ module ActionView #:nodoc:
         stringish.to_s.html_safe
       end
 
-      # This method returns a html safe string similar to what <tt>Array#join</tt>
+      # This method returns an html safe string similar to what <tt>Array#join</tt>
       # would return. The array is flattened, and all items, including
       # the supplied separator, are html escaped unless they are html
       # safe, and the returned string is marked as html safe.
diff --git a/actionview/lib/action_view/helpers/rendering_helper.rb b/actionview/lib/action_view/helpers/rendering_helper.rb
index ebfc35a4c7..6cd6e858dd 100644
--- a/actionview/lib/action_view/helpers/rendering_helper.rb
+++ b/actionview/lib/action_view/helpers/rendering_helper.rb
@@ -13,13 +13,13 @@ module ActionView
       # * <tt>:inline</tt> - Renders an inline template similar to how it's done in the controller.
       # * <tt>:text</tt> - Renders the text passed in out.
       # * <tt>:plain</tt> - Renders the text passed in out. Setting the content
-      # type as <tt>text/plain</tt>.
+      #   type as <tt>text/plain</tt>.
       # * <tt>:html</tt> - Renders the html safe string passed in out, otherwise
-      # performs html escape on the string first. Setting the content type as
-      # <tt>text/html</tt>.
+      #   performs html escape on the string first. Setting the content type as
+      #   <tt>text/html</tt>.
       # * <tt>:body</tt> - Renders the text passed in, and inherits the content
-      # type of <tt>text/html</tt> from <tt>ActionDispatch::Response</tt>
-      # object.
+      #   type of <tt>text/html</tt> from <tt>ActionDispatch::Response</tt>
+      #   object.
       #
       # If no options hash is passed or :update specified, the default is to render a partial and use the second parameter
       # as the locals hash.
diff --git a/actionview/lib/action_view/helpers/tags/select.rb b/actionview/lib/action_view/helpers/tags/select.rb
index 00881d9978..180900cc8d 100644
--- a/actionview/lib/action_view/helpers/tags/select.rb
+++ b/actionview/lib/action_view/helpers/tags/select.rb
@@ -3,7 +3,7 @@ module ActionView
     module Tags # :nodoc:
       class Select < Base # :nodoc:
         def initialize(object_name, method_name, template_object, choices, options, html_options)
-          @choices = block_given? ? template_object.capture { yield } : choices
+          @choices = block_given? ? template_object.capture { yield || "" } : choices
           @choices = @choices.to_a if @choices.is_a?(Range)
 
           @html_options = html_options
diff --git a/actionview/lib/action_view/log_subscriber.rb b/actionview/lib/action_view/log_subscriber.rb
index 6c8d9cb5bf..9047dbdd85 100644
--- a/actionview/lib/action_view/log_subscriber.rb
+++ b/actionview/lib/action_view/log_subscriber.rb
@@ -13,11 +13,11 @@ module ActionView
     end
 
     def render_template(event)
-      return unless logger.info?
-      message = "  Rendered #{from_rails_root(event.payload[:identifier])}"
-      message << " within #{from_rails_root(event.payload[:layout])}" if event.payload[:layout]
-      message << " (#{event.duration.round(1)}ms)"
-      info(message)
+      info do
+        message = "  Rendered #{from_rails_root(event.payload[:identifier])}"
+        message << " within #{from_rails_root(event.payload[:layout])}" if event.payload[:layout]
+        message << " (#{event.duration.round(1)}ms)"
+      end
     end
     alias :render_partial :render_template
     alias :render_collection :render_template
diff --git a/actionview/lib/action_view/lookup_context.rb b/actionview/lib/action_view/lookup_context.rb
index 5fff6b0771..ea687d9cca 100644
--- a/actionview/lib/action_view/lookup_context.rb
+++ b/actionview/lib/action_view/lookup_context.rb
@@ -66,10 +66,7 @@ module ActionView
       def self.get(details)
         if details[:formats]
           details = details.dup
-          syms    = Set.new Mime::SET.symbols
-          details[:formats] = details[:formats].select { |v|
-            syms.include? v
-          }
+          details[:formats] &= Mime::SET.symbols
         end
         @details_keys[details] ||= new
       end
diff --git a/actionview/lib/action_view/renderer/abstract_renderer.rb b/actionview/lib/action_view/renderer/abstract_renderer.rb
index 73c19a0ae2..1f122f9bc6 100644
--- a/actionview/lib/action_view/renderer/abstract_renderer.rb
+++ b/actionview/lib/action_view/renderer/abstract_renderer.rb
@@ -29,8 +29,9 @@ module ActionView
 
     def extract_details(options)
       @lookup_context.registered_details.each_with_object({}) do |key, details|
-        next unless value = options[key]
-        details[key] = Array(value)
+        value = options[key]
+
+        details[key] = Array(value) if value
       end
     end
 
@@ -41,6 +42,7 @@ module ActionView
     def prepend_formats(formats)
       formats = Array(formats)
       return if formats.empty? || @lookup_context.html_fallback_for_js
+
       @lookup_context.formats = formats | @lookup_context.formats
     end
   end
diff --git a/actionview/lib/action_view/renderer/partial_renderer.rb b/actionview/lib/action_view/renderer/partial_renderer.rb
index 36f17f01fd..0407632435 100644
--- a/actionview/lib/action_view/renderer/partial_renderer.rb
+++ b/actionview/lib/action_view/renderer/partial_renderer.rb
@@ -1,6 +1,33 @@
 require 'thread_safe'
 
 module ActionView
+  class PartialIteration
+    # The number of iterations that will be done by the partial.
+    attr_reader :size
+
+    # The current iteration of the partial.
+    attr_reader :index
+
+    def initialize(size)
+      @size  = size
+      @index = 0
+    end
+
+    # Check if this is the first iteration of the partial.
+    def first?
+      index == 0
+    end
+
+    # Check if this is the last iteration of the partial.
+    def last?
+      index == size - 1
+    end
+
+    def iterate! # :nodoc:
+      @index += 1
+    end
+  end
+
   # = Action View Partials
   #
   # There's also a convenience method for rendering sub templates within the current controller that depends on a
@@ -56,8 +83,12 @@ module ActionView
   #   <%= render partial: "ad", collection: @advertisements %>
   #
   # This will render "advertiser/_ad.html.erb" and pass the local variable +ad+ to the template for display. An
-  # iteration counter will automatically be made available to the template with a name of the form
-  # +partial_name_counter+. In the case of the example above, the template would be fed +ad_counter+.
+  # iteration object will automatically be made available to the template with a name of the form
+  # +partial_name_iteration+. The iteration object has knowledge about which index the current object has in
+  # the collection and the total size of the collection. The iteration object also has two convenience methods,
+  # +first?+ and +last?+. In the case of the example above, the template would be fed +ad_iteration+.
+  # For backwards compatibility the +partial_name_counter+ is still present and is mapped to the iteration's
+  # +index+ method.
   #
   # The <tt>:as</tt> option may be used when rendering partials.
   #
@@ -281,6 +312,8 @@ module ActionView
       end
     end
 
+    private
+
     def render_collection
       return nil if @collection.blank?
 
@@ -322,25 +355,27 @@ module ActionView
     # respond to +to_partial_path+ in order to setup the path.
     def setup(context, options, block)
       @view   = context
-      partial = options[:partial]
-
       @options = options
-      @locals  = options[:locals] || {}
       @block   = block
+
+      @locals  = options[:locals] || {}
       @details = extract_details(options)
 
       prepend_formats(options[:formats])
 
+      partial = options[:partial]
+
       if String === partial
         @object     = options[:object]
+        @collection = collection_from_options
         @path       = partial
-        @collection = collection
       else
         @object = partial
+        @collection = collection_from_object || collection_from_options
 
-        if @collection = collection_from_object || collection
+        if @collection
           paths = @collection_data = @collection.map { |o| partial_path(o) }
-          @path = paths.uniq.size == 1 ? paths.first : nil
+          @path = paths.uniq.one? ? paths.first : nil
         else
           @path = partial_path
         end
@@ -352,7 +387,7 @@ module ActionView
       end
 
       if @path
-        @variable, @variable_counter = retrieve_variable(@path, as)
+        @variable, @variable_counter, @variable_iteration = retrieve_variable(@path, as)
         @template_keys = retrieve_template_keys
       else
         paths.map! { |path| retrieve_variable(path, as).unshift(path) }
@@ -361,7 +396,7 @@ module ActionView
       self
     end
 
-    def collection
+    def collection_from_options
       if @options.key?(:collection)
         collection = @options[:collection]
         collection.respond_to?(:to_ary) ? collection.to_ary : []
@@ -373,9 +408,7 @@ module ActionView
     end
 
     def find_partial
-      if path = @path
-        find_template(path, @template_keys)
-      end
+      find_template(@path, @template_keys) if @path
     end
 
     def find_template(path, locals)
@@ -385,19 +418,22 @@ module ActionView
 
     def collection_with_template
       view, locals, template = @view, @locals, @template
-      as, counter = @variable, @variable_counter
+      as, counter, iteration = @variable, @variable_counter, @variable_iteration
 
       if layout = @options[:layout]
         layout = find_template(layout, @template_keys)
       end
 
-      index = -1
+      partial_iteration = PartialIteration.new(@collection.size)
+      locals[iteration] = partial_iteration
+
       @collection.map do |object|
-        locals[as]      = object
-        locals[counter] = (index += 1)
+        locals[as]        = object
+        locals[counter]   = partial_iteration.index
 
         content = template.render(view, locals)
         content = layout.render(view, locals) { content } if layout
+        partial_iteration.iterate!
         content
       end
     end
@@ -407,16 +443,20 @@ module ActionView
       cache = {}
       keys  = @locals.keys
 
-      index = -1
+      partial_iteration = PartialIteration.new(@collection.size)
+
       @collection.map do |object|
-        index += 1
-        path, as, counter = collection_data[index]
+        index = partial_iteration.index
+        path, as, counter, iteration = collection_data[index]
 
-        locals[as]      = object
-        locals[counter] = index
+        locals[as]        = object
+        locals[counter]   = index
+        locals[iteration] = partial_iteration
 
         template = (cache[path] ||= find_template(path, keys + [as, counter]))
-        template.render(view, locals)
+        content = template.render(view, locals)
+        partial_iteration.iterate!
+        content
       end
     end
 
@@ -466,8 +506,11 @@ module ActionView
 
     def retrieve_template_keys
       keys = @locals.keys
-      keys << @variable         if @object || @collection
-      keys << @variable_counter if @collection
+      keys << @variable if @object || @collection
+      if @collection
+        keys << @variable_counter
+        keys << @variable_iteration
+      end
       keys
     end
 
@@ -477,8 +520,11 @@ module ActionView
         raise_invalid_identifier(path) unless base =~ /\A_?([a-z]\w*)(\.\w+)*\z/
         $1.to_sym
       end
-      variable_counter = :"#{variable}_counter" if @collection
-      [variable, variable_counter]
+      if @collection
+        variable_counter = :"#{variable}_counter"
+        variable_iteration = :"#{variable}_iteration"
+      end
+      [variable, variable_counter, variable_iteration]
     end
 
     IDENTIFIER_ERROR_MESSAGE = "The partial name (%s) is not a valid Ruby identifier; " +
diff --git a/actionview/lib/action_view/renderer/template_renderer.rb b/actionview/lib/action_view/renderer/template_renderer.rb
index be17097428..f3a48ecfa0 100644
--- a/actionview/lib/action_view/renderer/template_renderer.rb
+++ b/actionview/lib/action_view/renderer/template_renderer.rb
@@ -6,19 +6,18 @@ module ActionView
       @view    = context
       @details = extract_details(options)
       template = determine_template(options)
-      context  = @lookup_context
 
       prepend_formats(template.formats)
 
-      unless context.rendered_format
-        context.rendered_format = template.formats.first || formats.first
-      end
+      @lookup_context.rendered_format ||= (template.formats.first || formats.first)
 
       render_template(template, options[:layout], options[:locals])
     end
 
+    private
+
     # Determine the template to be rendered using the given options.
-    def determine_template(options) #:nodoc:
+    def determine_template(options)
       keys = options.fetch(:locals, {}).keys
 
       if options.key?(:body)
diff --git a/actionview/lib/action_view/rendering.rb b/actionview/lib/action_view/rendering.rb
index c92d090cce..81d5836a8c 100644
--- a/actionview/lib/action_view/rendering.rb
+++ b/actionview/lib/action_view/rendering.rb
@@ -35,12 +35,13 @@ module ActionView
     module ClassMethods
       def view_context_class
         @view_context_class ||= begin
-          routes = respond_to?(:_routes) && _routes
+          include_path_helpers = supports_path?
+          routes  = respond_to?(:_routes)  && _routes
           helpers = respond_to?(:_helpers) && _helpers
 
           Class.new(ActionView::Base) do
             if routes
-              include routes.url_helpers
+              include routes.url_helpers(include_path_helpers)
               include routes.mounted_helpers
             end
 
diff --git a/actionview/lib/action_view/test_case.rb b/actionview/lib/action_view/test_case.rb
index 4c65860423..7edfc436a6 100644
--- a/actionview/lib/action_view/test_case.rb
+++ b/actionview/lib/action_view/test_case.rb
@@ -264,7 +264,7 @@ module ActionView
 
       def method_missing(selector, *args)
         if @controller.respond_to?(:_routes) &&
-          ( @controller._routes.named_routes.helpers.include?(selector) ||
+          ( @controller._routes.named_routes.route_defined?(selector) ||
             @controller._routes.mounted_helpers.method_defined?(selector) )
           @controller.__send__(selector, *args)
         else