Merge pull request #6986 from kennyj/fix_6975

Fix #6975. Round usec when writing timestamp attribute.

Conflicts:
	activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb

1 files changed, 15 insertions, 0 deletions

diff --git a/activerecord/test/cases/dirty_test.rb b/activerecord/test/cases/dirty_test.rb
index 26afd203d2..3bd2e909d7 100644
--- a/activerecord/test/cases/dirty_test.rb
+++ b/activerecord/test/cases/dirty_test.rb
@@ -521,6 +521,21 @@ class DirtyTest < ActiveRecord::TestCase
     assert !pirate.previous_changes.key?('created_on')
   end
 
+  def test_setting_time_attributes_with_time_zone_field_to_same_time_should_not_be_marked_as_a_change
+    in_time_zone 'Paris' do
+      target = Class.new(ActiveRecord::Base)
+      target.table_name = 'pirates'
+
+      created_on = Time.now
+
+      pirate = target.create(:created_on => created_on)
+      pirate.reload # Here mysql truncate the usec value to 0
+      
+      pirate.created_on = created_on
+      assert !pirate.created_on_changed?
+    end
+  end
+
   private
     def with_partial_updates(klass, on = true)
       old = klass.partial_updates?