add missing convert_to_model method, and do not create @response object

lib/action_view/helpers/dynamic_form.rb

@@ -87,6 +87,10 @@ def form(record_name, options = {})
         contents.safe_concat('</form>')
       end
 
+      def convert_to_model(object)
+        object.respond_to?(:to_model) ? object.to_model : object
+      end
+
       # Returns a string containing the error message attached to the +method+ on the +object+ if one exists.
       # This error message is wrapped in a <tt>DIV</tt> tag by default or with <tt>:html_tag</tt> if specified,
       # which can be extended to include a <tt>:prepend_text</tt> and/or <tt>:append_text</tt> (to properly explain

test/dynamic_form_test.rb

@@ -122,8 +122,6 @@ def setup
     super
     setup_post
     setup_user
-
-    @response = ActionController::TestResponse.new
   end
 
   def url_for(options)
@@ -370,7 +368,7 @@ def test_default_form_builder_no_instance_variable
 
     assert_dom_equal expected, output_buffer
   end
-  
+
   def test_error_messages_without_prefixed_attribute_name
     error = error_messages_for(@post)
     assert_dom_equal %(<div class="errorExplanation" id="errorExplanation"><h2>1 error prohibited this post from being saved</h2><p>There were problems with the following fields:</p><ul><li>Author name can't be empty</li></ul></div>),