ml_* % add 10 breaks

[petteraas]

While working with #43 I got some problem with the 'ml_* % add 10' functionality

ml_sonos_playlists % add 9
Traceback (most recent call last):
  File "/home/petter/.virtualenvs/python2.7/bin/socos", line 9, in <module>
    load_entry_point('socos==0.1', 'console_scripts', 'socos')()
  File "/home/petter/.virtualenvs/python2.7/local/lib/python2.7/site-packages/socos/runner.py", line 22, in main
    shell()
  File "/home/petter/.virtualenvs/python2.7/local/lib/python2.7/site-packages/socos/core.py", line 165, in shell
    process_cmd(args)
  File "/home/petter/.virtualenvs/python2.7/local/lib/python2.7/site-packages/socos/core.py", line 75, in process_cmd
    for line in result:
  File "/home/petter/.virtualenvs/python2.7/local/lib/python2.7/site-packages/socos/music_lib.py", line 207, in sonos_playlists
    for string in self._search_and_play(sonos, 'sonos_playlists', *args):
  File "/home/petter/.virtualenvs/python2.7/local/lib/python2.7/site-packages/socos/music_lib.py", line 238, in _search_and_play
    yield self._play(sonos, data_type, results, *args)
  File "/home/petter/.virtualenvs/python2.7/local/lib/python2.7/site-packages/socos/music_lib.py", line 323, in _play
    sonos.add_to_queue(item)
  File "/home/petter/.virtualenvs/python2.7/local/lib/python2.7/site-packages/soco/core.py", line 1243, in add_to_queue
    ('EnqueueAsNext', 1)
  File "/home/petter/.virtualenvs/python2.7/local/lib/python2.7/site-packages/soco/services.py", line 157, in _dispatcher
    return self.send_command(action, *args, **kwargs)
  File "/home/petter/.virtualenvs/python2.7/local/lib/python2.7/site-packages/soco/services.py", line 348, in send_command
    self.handle_upnp_error(response.text)
  File "/home/petter/.virtualenvs/python2.7/local/lib/python2.7/site-packages/soco/services.py", line 408, in handle_upnp_error
    error_xml=xml_error
soco.exceptions.SoCoUPnPException: UPnP Error 800 received:  from 10.0.4.2

same problem when I try 'replace',

to be a bit more sure it's not my setup I created a new virtualenv and confirmed the same problem in it ( that test was with master branch )

this also broke with the various other ml_ commands, no matter which branch I tested.

[petteraas]

Nope sorry, this was userfault, forgot that I redid the coordinator setup while working on something else, so I tried to send all these commands to a slave!

However, if the UPnP Error 800 specifically implies that you tried a command on a slave that should have gone to a master, perhaps we should catch it and handle it as just that for the user.

[stefankoegl]

Related to the discussion in SoCo/SoCo#138, I guess.

[stefankoegl]

Should we keep the issue open for proper handling of exceptions?

[petteraas]

@stefankoegl I would say keep this issue open until we see the outcome of SoCo/SoCo#138, based on that we either code up something here or not!