R12 Purchasing: PO lines are validated even though they were cancelled

On R12.1.1 "Canceled PO Lines Are Getting Validated During PO Approval" in Purchasing per My Oracle Support note ID 2169842.1 when at least one line is cancelled from a PO that has already been approved!  The good news is that there is a patch, and that you can design a testing scenario to validate that this issue does not come back in the future!