test(remoteshell): pin the signal that stops the ssh daemon

Check that no kill in the postscript gives the signal number without a hyphen,
and that the ssh daemon gets the signal that a process cannot catch.

xCAT-test/unit/remoteshell_kill_signal.t

@@ -0,0 +1,26 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+
+use File::Spec;
+use FindBin;
+use Test::More;
+
+my $script = File::Spec->catfile( $FindBin::Bin, '..', '..',
+    'xCAT', 'postscripts', 'remoteshell' );
+plan skip_all => 'remoteshell not found' unless -r $script;
+
+open( my $fh, '<', $script ) or die "Unable to read $script: $!";
+my $source = do { local $/; <$fh> };
+close($fh);
+
+# A kill without the hyphen reads the signal number as one more process id, so
+# the target gets the default signal, which a process can catch, and the
+# process with that id is signalled as well.
+my @bare = ( $source =~ /^[^#\n]*\bkill\s+\d/gm );
+is( scalar(@bare), 0, 'no kill gives the signal number without a hyphen' );
+
+like( $source, qr/kill -9 \$PIDLIST/,
+    'the ssh daemon gets the signal that a process cannot catch' );
+
+done_testing();