Allow layout rendering to access current object being rendered when using partial + collection

actionpack/lib/action_view/renderer/partial_renderer.rb

@@ -283,13 +283,19 @@ module ActionView
       end
 
       if layout = @options[:layout]
-        layout = find_template(layout)
+        layout = find_template(layout, @locals.keys + [@variable])
       end
 
       result = @template ? collection_with_template : collection_without_template
-      
-      result.map!{|content| layout.render(@view, @locals) { content } } if layout
-      
+
+      if layout
+        locals = @locals
+        result.map! do |content|
+          locals[@variable] = @collection[result.index(content)]
+          layout.render(@view, @locals) { content }
+        end
+      end
+
       result.join(spacer).html_safe
     end
 
@@ -391,10 +397,9 @@ module ActionView
         locals[as] = object
         segments << template.render(@view, locals)
       end
-      
+
       segments
     end
-    
 
     def collection_without_template
       segments, locals, collection_data = [], @locals, @collection_data

actionpack/test/fixtures/test/_b_layout_for_partial_with_object.html.erb

@@ -0,0 +1 @@
+<b class="<%= customer.name.downcase %>"><%= yield %></b>

actionpack/test/template/render_test.rb

@@ -233,11 +233,15 @@ module RenderTestCases
   def test_render_partial_with_nil_values_in_collection
     assert_equal "Hello: davidHello: Anonymous", @view.render(:partial => "test/customer", :collection => [ Customer.new("david"), nil ])
   end
-  
+
   def test_render_partial_with_layout_using_collection_and_template
     assert_equal "<b>Hello: Amazon</b><b>Hello: Yahoo</b>", @view.render(:partial => "test/customer", :layout => 'test/b_layout_for_partial', :collection => [ Customer.new("Amazon"), Customer.new("Yahoo") ])
   end
 
+  def test_render_partial_with_layout_using_collection_and_template_makes_current_item_available_in_template
+    assert_equal '<b class="amazon">Hello: Amazon</b><b class="yahoo">Hello: Yahoo</b>', @view.render(:partial => "test/customer", :layout => 'test/b_layout_for_partial_with_object', :collection => [ Customer.new("Amazon"), Customer.new("Yahoo") ])
+  end
+
   def test_render_partial_with_empty_array_should_return_nil
     assert_nil @view.render(:partial => [])
   end
@@ -310,7 +314,7 @@ module RenderTestCases
     ActionView::Template.register_template_handler :foo, CustomHandler
     assert_equal 'source: "Hello, <%= name %>!"', @view.render(:inline => "Hello, <%= name %>!", :locals => { :name => "Josh" }, :type => :foo)
   end
-  
+
   def test_render_knows_about_types_registered_when_extensions_are_checked_earlier_in_initialization
     ActionView::Template::Handlers.extensions
     ActionView::Template.register_template_handler :foo, CustomHandler