ExitOnForwardFailure=yes doesn't exit if adress is already in use and no binding adress is specified

[Michał Wadas]

First, let's setup some process that binds to port that we intend to use:

python -m SimpleHTTPServer 8000

Then try few commands:

ssh -N -L 5000:localhost:5432 foobar # Fails and hangs

ssh -o ExitOnForwardFailure=yes -N -L 5000:localhost:5432 foobar # Fails
and hangs

ssh -N -L 127.0.0.1:5000:localhost:5432 foobar # Fails and hangs

ssh -o ExitOnForwardFailure=yes -N -L 127.0.0.1:5000:localhost:5432 foobar
# Fails and exits

I'm running OpenSSH_7.9p1, OpenSSL 1.0.2n on Ubuntu 18.04 (16.04 + 7.9
fails too).