TimeWithZone #in_time_zone returns +self+ if zone argument is the same as #time_zone

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8853 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activesupport/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* TimeWithZone #in_time_zone returns +self+ if zone argument is the same as #time_zone [Geoff Buesing]
+
 * Adding TimeWithZone #to_a, #to_f, #to_i, #httpdate, #rfc2822 [Geoff Buesing]
 
 * Pruning unneeded TimeWithZone#change_time_zone_to_current [Geoff Buesing]

activesupport/lib/active_support/time_with_zone.rb

@@ -29,6 +29,7 @@ module ActiveSupport
 
     # Returns the simultaneous time in the specified zone
     def in_time_zone(new_zone)
+      return self if time_zone == new_zone
       utc.in_time_zone(new_zone)
     end
   

activesupport/test/core_ext/time_with_zone_test.rb

@@ -25,6 +25,10 @@ uses_tzinfo 'TimeWithZoneTest' do
     def test_in_time_zone
       assert_equal ActiveSupport::TimeWithZone.new(@utc, TimeZone['Alaska']), @twz.in_time_zone('Alaska')
     end
+    
+    def test_in_time_zone_with_new_zone_equal_to_old_zone_does_not_create_new_object
+      assert_equal @twz.object_id, @twz.in_time_zone(TimeZone['Eastern Time (US & Canada)']).object_id
+    end
   
     def test_in_current_time_zone
       Time.use_zone 'Alaska' do