Add test for warning and CHANGELOG entry

actionpack/CHANGELOG

 *Rails 3.2.0 (unreleased)*
 
+* Changed log level of warning for missing CSRF token from :debug to :warn. Fixes #2972 [Mike Dillon]
+
 * content_tag_for and div_for can now take the collection of records. It will also yield the record as the first argument if you set a receiving argument in your block [Prem Sichanugrist]
 
   So instead of having to do this:

actionpack/test/controller/request_forgery_protection_test.rb

 require 'abstract_unit'
 require 'digest/sha1'
 require 'active_support/core_ext/string/strip'
+require "active_support/log_subscriber/test_helper"
 
 # common controller actions
 module RequestForgeryProtectionActions
@@ -157,6 +158,21 @@ def test_should_allow_put_with_token_in_header
     assert_not_blocked { put :index }
   end
 
+  def test_should_warn_on_missing_csrf_token
+    old_logger = ActionController::Base.logger
+    logger = ActiveSupport::LogSubscriber::TestHelper::MockLogger.new
+    ActionController::Base.logger = logger
+
+    begin
+      assert_blocked { post :index }
+
+      assert_equal 1, logger.logged(:warn).size
+      assert_match(/CSRF token authenticity/, logger.logged(:warn).last)
+    rescue
+      ActionController::Base.logger = old_logger
+    end
+  end
+
   def assert_blocked
     session[:something_like_user_id] = 1
     yield