Add a test for rendering from the controller context.

actionpack/test/controller/new_base/render_context_test.rb

+require 'abstract_unit'
+
+module RenderContext
+  class BasicController < ActionController::Base
+    self.view_paths = [ActionView::FixtureResolver.new(
+      "render_context/basic/hello_world.html.erb" => "<%= @value %> from <%= self.__controller_method__ %>",
+      "layouts/basic.html.erb" => "?<%= yield %>?"
+    )]
+
+    # Include ViewContext
+    include ActionView::Context
+
+    # And initialize the required variables
+    before_filter do
+      @output_buffer = nil
+      @virtual_path  = nil
+      @view_flow     = ActionView::OutputFlow.new
+    end
+
+    def hello_world
+      @value = "Hello"
+      render :action => "hello_world", :layout => false
+    end
+
+    def with_layout
+      @value = "Hello"
+      render :action => "hello_world", :layout => "basic"
+    end
+
+    protected
+
+    def view_context
+      self
+    end
+
+    def __controller_method__
+      "controller context!"
+    end
+  end
+
+  class RenderContextTest < Rack::TestCase
+    test "rendering using the controller as context" do
+      get "/render_context/basic/hello_world"
+      assert_body "Hello from controller context!"
+      assert_status 200
+    end
+
+    test "rendering using the controller as context with layout" do
+      get "/render_context/basic/with_layout"
+      assert_body "?Hello from controller context!?"
+      assert_status 200
+    end
+  end
+end