Orchestrate runner crashes trying to parse highstate output

Description of Issue/Question

When running an state.orchestrate, it crashes at the end of the run with this Traceback:

IndexError: list index out of range
Traceback (most recent call last):
  File "/usr/bin/salt-run", line 10, in <module>
    salt_run()
  File "/usr/lib/python2.7/dist-packages/salt/scripts.py", line 403, in salt_run
    client.run()
  File "/usr/lib/python2.7/dist-packages/salt/cli/run.py", line 41, in run
    ret = runner.run()
  File "/usr/lib/python2.7/dist-packages/salt/runner.py", line 266, in run
    daemonize=False)
  File "/usr/lib/python2.7/dist-packages/salt/client/mixins.py", line 467, in _proc_function
    return self.low(fun, low, full_return=False)
  File "/usr/lib/python2.7/dist-packages/salt/client/mixins.py", line 256, in low
    return self._low(fun, low, print_event=print_event, full_return=full_return)
  File "/usr/lib/python2.7/dist-packages/salt/client/mixins.py", line 416, in _low
    namespaced_event.fire_event(data, 'ret')
  File "/usr/lib/python2.7/dist-packages/salt/utils/event.py", line 920, in fire_event
    self.print_func(tag, data)
  File "/usr/lib/python2.7/dist-packages/salt/client/mixins.py", line 545, in print_async_event
    salt.output.display_output(event_data, outputter, self.opts)
  File "/usr/lib/python2.7/dist-packages/salt/output/__init__.py", line 92, in display_output
    display_data = try_printout(data, out, opts, **kwargs)
  File "/usr/lib/python2.7/dist-packages/salt/output/__init__.py", line 39, in try_printout
    printout = get_printout(out, opts)(data, **kwargs)
  File "/usr/lib/python2.7/dist-packages/salt/output/highstate.py", line 145, in output
    for host, hostdata in six.iteritems(data)
  File "/usr/lib/python2.7/dist-packages/salt/output/highstate.py", line 222, in _format_host
    schanged, ctext = _format_changes(ret['changes'], orchestration)
  File "/usr/lib/python2.7/dist-packages/salt/output/highstate.py", line 522, in _format_changes
    s, c = _format_host(host, hostdata)
  File "/usr/lib/python2.7/dist-packages/salt/output/highstate.py", line 313, in _format_host
    if comps[1] != comps[2]:
IndexError: list index out of range

I narrowed the source down to this state:

{{ test_host }}:
  salt.function:
    - name: cloud.profile
    - tgt: {{ master }}
    - kwarg:
        profile: lxc_test
        names:
          - {{ test_host }}
        config_dir: /etc/salt

Its tname in the highstate outputter is just the value of the variable test_host, so comps is just a single item list. Here is the relevant output from that state during a run:

[INFO    ] Running state [cloud.profile] at time 16:57:24.445419
[INFO    ] Executing state salt.function for [cloud.profile]
[DEBUG   ] MasterEvent PUB socket URI: /var/run/salt/master/master_event_pub.ipc
[DEBUG   ] MasterEvent PULL socket URI: /var/run/salt/master/master_event_pull.ipc
[DEBUG   ] Initializing new IPCClient for path: /var/run/salt/master/master_event_pull.ipc
[DEBUG   ] Sending event: tag = salt/run/20180205165438108435/args; data = {'_stamp': '2018-02-05T21:57:24.446851', 'args': {'tgt_type': 'glob', 'ret': '', '_cmd_meta': True, 'kwarg': OrderedDict([('profile', 'lxc_test'), ('names', ['master.test.domain.internal']), ('config_dir', '/etc/salt')]), 'ssh': False, 'timeout': None, 'arg': [], 'expect_minions': False}, 'type': 'function', 'name': 'cloud.profile', 'tgt': 'salt.domain.internal'}
[DEBUG   ] Reading configuration from /etc/salt/master
[DEBUG   ] Including configuration from '/etc/salt/master.d/custom.conf'
[DEBUG   ] Reading configuration from /etc/salt/master.d/custom.conf
[DEBUG   ] Including configuration from '/etc/salt/master.d/reactor.conf'
[DEBUG   ] Reading configuration from /etc/salt/master.d/reactor.conf
[DEBUG   ] Using cached minion ID from /etc/salt/minion_id: salt.domain.internal
[DEBUG   ] Missing configuration file: /home/pete/.saltrc
[DEBUG   ] MasterEvent PUB socket URI: /var/run/salt/master/master_event_pub.ipc
[DEBUG   ] MasterEvent PULL socket URI: /var/run/salt/master/master_event_pull.ipc
[DEBUG   ] Initializing new AsyncZeroMQReqChannel for ('/etc/salt/pki/master', 'salt.domain.internal_master', 'tcp://127.0.0.1:4506', 'clear')
[DEBUG   ] Initializing new IPCClient for path: /var/run/salt/master/master_event_pub.ipc
[DEBUG   ] LazyLoaded local_cache.get_load
[DEBUG   ] Reading minion list from /var/cache/salt/master/jobs/8d/8e6dbba4b6732d43c8fe9331978ce5b9c095c5cf88f26ff624999cba984789/.minions.p
[DEBUG   ] get_iter_returns for jid 20180205165724512730 sent to set(['salt.domain.internal']) will timeout at 16:57:34.532774
...
[DEBUG   ] jid 20180205165724512730 return from salt.domain.internal
[DEBUG   ] jid 20180205165724512730 found all minions set(['salt.domain.internal'])
[INFO    ] {'ret': {'salt.domain.internal': {'master.test.domain.internal': {'comment': '', 'runner_return': {'comment': '', 'errors': {'test.domain.internal': {'master.test.domain.internal': []}}, 'test.domain.internal': [{'comment': "Container 'master.test.domain.internal' successfully initialized", 'changes': {'init': [{'create': 'Container created'}, {'config': 'Container configuration updated'}, {'password': 'Password(s) updated'}, {'dns': 'DNS updated'}, {'bootstrap': 'Container successfully bootstrapped'}, {'state': {'new': 'running', 'old': None}}]}, 'result': True, 'name': 'master.test.domain.internal', 'container_name': 'master.test.domain.internal'}], 'ping_status': True, 'done': [{'comment': "Container 'master.test.domain.internal' successfully initialized", 'changes': {'init': [{'create': 'Container created'}, {'config': 'Container configuration updated'}, {'password': 'Password(s) updated'}, {'dns': 'DNS updated'}, {'bootstrap': 'Container successfully bootstrapped'}, {'state': {'new': 'running', 'old': None}}]}, 'result': True, 'name': 'master.test.domain.internal', 'container_name': 'master.test.domain.internal'}], 'result': True}, 'changes': {'created': 'created'}, 'name': 'master.test.domain.internal', 'result': True}}}, 'out': 'highstate'}
[INFO    ] Completed state [cloud.profile] at time 16:59:02.882608 duration_in_ms=98437.188

Versions Report

I see this in both 2016.11 and 2017.7

Salt Version:
           Salt: 2017.7.2

Dependency Versions:
           cffi: Not Installed
       cherrypy: Not Installed
       dateutil: 2.4.0
      docker-py: Not Installed
          gitdb: 2.0.3
      gitpython: 2.1.8
          ioflo: Not Installed
         Jinja2: 2.7.2
        libgit2: Not Installed
        libnacl: Not Installed
       M2Crypto: 0.21.1
           Mako: 0.9.1
   msgpack-pure: Not Installed
 msgpack-python: 0.3.0
   mysql-python: 1.2.3
      pycparser: Not Installed
       pycrypto: 2.6.1
   pycryptodome: Not Installed
         pygit2: Not Installed
         Python: 2.7.6 (default, Nov 23 2017, 15:49:48)
   python-gnupg: 0.3.6
         PyYAML: 3.10
          PyZMQ: 14.0.1
           RAET: Not Installed
          smmap: 2.0.3
        timelib: Not Installed
        Tornado: 4.2.1
            ZMQ: 4.0.4

System Versions:
           dist: Ubuntu 14.04 trusty
         locale: UTF-8
        machine: x86_64
        release: 3.13.0-123-generic
         system: Linux
        version: Ubuntu 14.04 trusty

Start in salt/output/highstate.py, especially _format_host and _format_changes, using the traceback and the provided state.orchestrate example to reproduce the failure. Verify that an orchestration state whose tname produces a single-component list completes without IndexError and still renders its highstate output.