cssh does not respect empty ssh_args/rsh_args parameter option

[Jakub Witkowski]

I am using cssh in combination with a fairly complex script setting up the actual connection; this script takes no parameters other than the server name to connect to.

My configuration is essentially like this:

~/.clusterssh/config:
comms=ssh
ssh=connect-script
ssh_args=

This used to work properly in 14.04; however in Xenial, empty ssh_args is ignored:

$cssh --debug 4 test-server
[..]
comms=ssh
ssh=connect-script
ssh_args=
[...]
# Configuration dump produced by "cssh -u"
[...]
ssh=ssh
ssh_args=-x -o ConnectTimeout=10

$cssh --evaluate test-server
{evaluate}=test-server
Testing terminal - running command:
xterm -xrm '*.VT100.allowSendEvents:true' -e /usr/bin/perl -e 'print "Base terminal test
"; sleep 2'

Testing comms - running command:
connect-script -x -o ConnectTimeout=10 test-server hostname ; echo Got hostname via ssh; sleep 2

I used find and grep to check if the above options show up anywhere else in my configuration; the only files that I found were actual cssh/crsh/ccon/ctel programs and their man pages.

This is clusterssh version 4.05-2 installed on Ubuntu 16.04