Not proved in a unit test, but when removing items, it is safer to remove them in the reversed order. In fact, the previous code raises an exception, when an upgrade of a business template removes a workflow and a workflow chain related to this workflow at a time.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@29054 20353a03-c40f-0410-a6d1-a30d3c3de9de