NEWNYM does not abandon open rendezvous circuits
Tor has ignored a rendezvous circuit's
timestamp_dirty field when choosing whether to attach a new stream to it since hidden services were first implemented in version 0.0.6, but this became a Bad Thing when
SIGNAL NEWNYM was added in 0.1.1.15-rc (and implemented (uglily) by decreasing
timestamp_dirty by a large amount, to make previously used circuits seem ‘too old’ for new streams).