AssociationCollection should not do transaction if @owner.new_record?

I found that AssociationCollection#<< do empty transaction even if the @owner is new record.

>> firm = Firm.new
>> firm.clients << Client.new
BEGIN
COMMIT

I feel that this is not necessary. How about not doing empty transaction is such case?

diff --git a/activerecord/lib/active_record/associations/association_collection.rb b/activerecord/lib/active_record/associations/association_collection.rb
index 42b6e5d..850d0d5 100644
--- a/activerecord/lib/active_record/associations/association_collection.rb
+++ b/activerecord/lib/active_record/associations/association_collection.rb
@@ -137,6 +137,7 @@ module ActiveRecord
       #     # same effect as calling Book.transaction
       #   end
       def transaction(*args)
+        return yield if @owner.new_record?
         @reflection.klass.transaction(*args) do
           yield
         end

However, I'm not sure how to check this behavior in test. BEGIN and COMMIT are ignored
in assert_queries, and SQLite3 doesn't execute BEGIN/COMMIT AFAIK.

Thanks,