xapi-project/xen-api — pull request #1817 by johnelse (2014-07-01 17:22:12+00:00)
Title: CA-70188: Remove invalid pool patches from the database at xapi startup.

A pool_patch is valid if either:

- It has been applied to at least one host, or
- Its file exists on the master filesystem.

It neither of these is true, we can delete the pool_patch object.