Code review comment for lp:~edwin-grubbs/launchpad/bug-663861-product-series-timeout-part1

> So, a few things here.
> Patch #2208-26-0

Done.

> I thought we had a function for this in the DB already? Could you have a look
> for it and preferentially use it?

I can't find another one that will work properly. I added the milestone_sort_key() recently, but that takes a date field in addition to the version number.

> If we don't have one, this seems fine - but I think you should follow this
> patch up with a test that you get the sort order you expect.

I'll definitely add a test for that in the next branch.