Readd test for updated_at being nil

test/attachment_test.rb

@@ -1090,6 +1090,12 @@ class AttachmentTest < Test::Unit::TestCase
       assert_equal now.to_i, @dummy.avatar.updated_at.to_i
     end
 
+    should "return nil when reloaded and sent #avatar_updated_at" do
+      @dummy.save
+      @dummy.reload
+      assert_nil @dummy.avatar.updated_at
+    end
+
     should "return the right value when sent #avatar_file_size" do
       @dummy.avatar = @file
       assert_equal File.size(@file), @dummy.avatar.size