support remote port forwarding with a zero listen port (-R0:...) to
dyamically allocate a listen port at runtime (this is actually
specified in rfc4254); bz#1003 ok markus@
+ - djm@cvs.openbsd.org 2009/02/12 03:16:01
+ [serverloop.c]
+ tighten check for -R0:... forwarding: only allow dynamic allocation
+ if want_reply is set in the packet
20090212
- (djm) [sshpty.c] bz#1419: OSX uses cloning ptys that automagically