#919 Circular references between tickets (parent/child). Protect the framework against infinite recursions on cascaded updates (done at the DBUpdate level). 
#919 Circular references between tickets (parent/child). Protect the framework against infinite recursions on cascaded updates (done at the DBUpdate level). 

ucbpi/itop,ucbpi/itop,ucbpi/itop,ucbpi/itop,ucbpi/itop