salt-call with --retcode-passthrough returns exit code 2 if sls is empty

Description of Issue/Question

If I create an empty sls file (or it is rendered to an empty sls file), then using salt-call with --retcode-passthrough will return an exit code of 2. This is essentially a noop, so I'm not sure why that would be considered an error.

Setup

# cat /srv/salt/states/base/test.sls
{# empty state #}

Steps to Reproduce Issue

# salt-call --local --retcode-passthrough state.sls test
local:

Summary for local
-----------
Succeeded: 0
Failed:   0
-----------
Total states run:    0
Total run time:  0.000 ms
# echo $?
2

Versions Report

# salt-call --versions-report
Salt Version:
           Salt: 2016.11.2

Dependency Versions:
           cffi: Not Installed
       cherrypy: Not Installed
       dateutil: 2.6.0
          gitdb: Not Installed
      gitpython: Not Installed
          ioflo: Not Installed
         Jinja2: 2.8.1
        libgit2: Not Installed
        libnacl: Not Installed
       M2Crypto: Not Installed
           Mako: Not Installed
   msgpack-pure: Not Installed
 msgpack-python: 0.4.6
   mysql-python: Not Installed
      pycparser: Not Installed
       pycrypto: 2.6.1
         pygit2: Not Installed
         Python: 2.6.6 (r266:84292, Aug 18 2016, 15:13:37)
   python-gnupg: Not Installed
         PyYAML: 3.10
          PyZMQ: 14.5.0
           RAET: Not Installed
          smmap: Not Installed
        timelib: Not Installed
        Tornado: 4.2.1
            ZMQ: 4.0.5

System Versions:
           dist: centos 6.8 Final
        machine: x86_64
        release: 2.6.32-642.13.1.el6.x86_64
         system: Linux
        version: CentOS 6.8 Final

Start by reproducing the empty test.sls case with salt-call --local state.sls test and --retcode-passthrough, then trace how the state.sls result is converted into the command exit code. Done means an empty or rendered-empty SLS is treated as a no-op and does not return exit code 2.