Merge commit 'rails/master'

Conflicts:
	activerecord/lib/active_record/calculations.rb
	activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
	activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

1 files changed, 10 insertions, 0 deletions

diff --git a/activerecord/test/cases/dirty_test.rb b/activerecord/test/cases/dirty_test.rb
index 1441421a80..74571d923a 100644
--- a/activerecord/test/cases/dirty_test.rb
+++ b/activerecord/test/cases/dirty_test.rb
@@ -298,6 +298,16 @@ class DirtyTest < ActiveRecord::TestCase
     end
   end
 
+  def test_save_should_not_save_serialized_attribute_with_partial_updates_if_not_present
+    with_partial_updates(Topic) do
+      Topic.create!(:author_name => 'Bill', :content => {:a => "a"})
+      topic = Topic.first(:select => 'id, author_name')
+      topic.update_attribute :author_name, 'John'
+      topic = Topic.first
+      assert_not_nil topic.content
+    end
+  end
+
   private
     def with_partial_updates(klass, on = true)
       old = klass.partial_updates?