Prevents a crash when queried for a record whose RDATA exceeds 65535 bytes. Prevents a crash when validating caused by using "Bad cache" data before it has been initialized. ISC_QUEUE handling for recursive clients was updated to address a race condition that could cause a memory leak. This rarely occurred with UDP clients, but could be a significant problem for a server handling a steady rate of TCP queries. A condition has been corrected where improper handling of zero-length RDATA could cause undesirable behavior, including termination of the named process.