Add test coverage for implicit render in empty actions

actionpack/test/controller/render_test.rb

@@ -24,6 +24,11 @@ def with_template
   end
 end
 
+class ImplicitRenderTestController < ActionController::Base
+  def empty_action
+  end
+end
+
 class TestController < ActionController::Base
   protect_from_forgery
 
@@ -463,6 +468,15 @@ def test_access_to_logger_in_view
   end
 end
 
+class ImplicitRenderTest < ActionController::TestCase
+  tests ImplicitRenderTestController
+
+  def test_implicit_no_content_response
+    get :empty_action
+    assert_response :no_content
+  end
+end
+
 class HeadRenderTest < ActionController::TestCase
   tests TestController