Added timestamp_attributes_for_create_in_model

Signed-off-by: NSantiago Pastorino <santiago@wyeworks.com>

activerecord/lib/active_record/timestamp.rb

@@ -66,6 +66,10 @@ def should_record_timestamps?
       self.record_timestamps && (!partial_updates? || changed? || (attributes.keys & self.class.serialized_attributes.keys).present?)
     end
 
+    def timestamp_attributes_for_create_in_model
+      timestamp_attributes_for_create.select { |c| self.class.column_names.include?(c.to_s) }
+    end
+
     def timestamp_attributes_for_update_in_model
       timestamp_attributes_for_update.select { |c| self.class.column_names.include?(c.to_s) }
     end

activerecord/test/cases/timestamp_test.rb

@@ -155,4 +155,9 @@ def test_all_timestamp_attributes
     toy = Toy.first
     assert_equal toy.send(:all_timestamp_attributes), [:created_at, :created_on, :updated_at, :updated_on]
   end
+
+  def test_timestamp_attributes_for_create_in_model
+    toy = Toy.first
+    assert_equal toy.send(:timestamp_attributes_for_create_in_model), [:created_at]
+  end
 end