TimeWithZone#freeze: preload instance variables so that we can actually freeze

activesupport/CHANGELOG

@@ -1,5 +1,7 @@
 *Edge*
 
+* TimeWithZone#freeze: preload instance variables so that we can actually freeze [Geoff Buesing]
+
 * Fix Brasilia timezone #1180 [Marcus Derencius, Kane]
 
 * Time#advance recognizes fractional days and weeks. Deprecate Durations of fractional months and years #970 [Tom Lea]

activesupport/lib/active_support/time_with_zone.rb

@@ -277,9 +277,9 @@ module ActiveSupport
     end
     alias_method :kind_of?, :is_a?
 
-    # Neuter freeze because freezing can cause problems with lazy loading of attributes.
     def freeze
-      self
+      period; utc; time # preload instance variables before freezing
+      super
     end
 
     def marshal_dump

activesupport/test/core_ext/time_with_zone_test.rb

@@ -386,6 +386,19 @@ class TimeWithZoneTest < Test::Unit::TestCase
     end
   end
   
+  def test_freeze
+    @twz.freeze
+    assert @twz.frozen?
+  end
+  
+  def test_freeze_preloads_instance_variables
+    @twz.freeze
+    assert_nothing_raised do
+      @twz.period
+      @twz.time
+    end
+  end
+
   uses_mocha 'TestDatePartValueMethods' do
     def test_method_missing_with_non_time_return_value
       silence_warnings do # silence warnings raised by tzinfo gem