tests: Added a check for unaccessible global known_hosts

Verify that the check process will not fail if the global known_hosts
file is not accessible and the local known_hosts file contain the host.

Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
(cherry picked from commit 8e42ed8)

Author: ansasaki

tests/unittests/torture_knownhosts_parsing.c

@@ -381,13 +381,22 @@ static void torture_knownhosts_host_exists(void **state)
 
     ssh_options_set(session, SSH_OPTIONS_HOST, "localhost");
     ssh_options_set(session, SSH_OPTIONS_KNOWNHOSTS, knownhosts_file);
+
     /* This makes sure the system's known_hosts are not used */
     ssh_options_set(session, SSH_OPTIONS_GLOBAL_KNOWNHOSTS, "/dev/null");
 
     found = ssh_session_has_known_hosts_entry(session);
     assert_int_equal(found, SSH_KNOWN_HOSTS_OK);
     assert_true(found == SSH_KNOWN_HOSTS_OK);
 
+    /* This makes sure the check will not fail when the system's known_hosts is
+     * not accessible*/
+    ssh_options_set(session, SSH_OPTIONS_GLOBAL_KNOWNHOSTS, "./unaccessible");
+
+    found = ssh_session_has_known_hosts_entry(session);
+    assert_int_equal(found, SSH_KNOWN_HOSTS_OK);
+    assert_true(found == SSH_KNOWN_HOSTS_OK);
+
     ssh_options_set(session, SSH_OPTIONS_HOST, "wurstbrot");
     found = ssh_session_has_known_hosts_entry(session);
     assert_true(found == SSH_KNOWN_HOSTS_UNKNOWN);