- dtucker@cvs.openbsd.org 2013/06/07 15:37:52
     [channels.c channels.h clientloop.c]
     Add an "ABANDONED" channel state and use for mux sessions that are
     disconnected via the ~. escape sequence.  Channels in this state will
     be able to close if the server responds, but do not count as active channels.
     This means that if you ~. all of the mux clients when using ControlPersist
     on a broken network, the backgrounded mux master will exit when the
     Control Persist time expires rather than hanging around indefinitely.
     bz#1917, also reported and tested by tedu@.  ok djm@ markus@.