render_to_string should have the identical signature as render

actionpack/lib/abstract_controller/rendering.rb

@@ -89,9 +89,16 @@ def view_context
     # Normalize arguments, options and then delegates render_to_body and
     # sticks the result in self.response_body.
     def render(*args, &block)
+      self.response_body = render_to_string(*args, &block)
+    end
+
+    # Raw rendering of a template to a string. Just convert the results of
+    # render_to_body into a String.
+    # :api: plugin
+    def render_to_string(*args, &block)
       options = _normalize_args(*args, &block)
       _normalize_options(options)
-      self.response_body = render_to_body(options)
+      render_to_body(options)
     end
 
     # Raw rendering of a template to a Rack-compatible body.
@@ -101,14 +108,6 @@ def render_to_body(options = {})
       _render_template(options)
     end
 
-    # Raw rendering of a template to a string. Just convert the results of
-    # render_to_body into a String.
-    # :api: plugin
-    def render_to_string(options={})
-      _normalize_options(options)
-      render_to_body(options)
-    end
-
     # Find and renders a template based on the options given.
     # :api: private
     def _render_template(options) #:nodoc:

actionpack/test/abstract/abstract_controller_test.rb

@@ -49,6 +49,11 @@ def index
         render "index.erb"
       end
       
+
+      def index_to_string
+        self.response_body = render_to_string "index.erb"
+      end
+
       def action_with_ivars
         @my_ivar = "Hello"
         render "action_with_ivars.erb"
@@ -77,6 +82,11 @@ def setup
         assert_equal "Hello from index.erb", @controller.response_body
       end
       
+      test "render_to_string works with a String as an argument" do
+        @controller.process(:index_to_string)
+        assert_equal "Hello from index.erb", @controller.response_body
+      end
+
       test "rendering passes ivars to the view" do
         @controller.process(:action_with_ivars)
         assert_equal "Hello from index_with_ivars.erb", @controller.response_body