spree/spree — pull request #1423 by cwise (2012-04-20 14:10:14+00:00)
Title: Corrected an issue with ensuring there is only one default tax category

There is a callback after updating a TaxCategory that attempts to ensure that there is only a single default in the database. The issue is that if you happen to be updating the current default tax category, you will stomp it's default status (try the second test that I added to see it fails on master).

We noticed this when one of our guys updated the description on a tax category using the admin control panel and we suddenly started receiving orders without taxes applied because there was no longer a default tax category (pretty nasty!).