[BUG] ValueError in zc_decode

[jimboca]

Describe the bug

I've been running with this library for a long time and first time I noticed this error, very strange character imbedded in this message.

2022-04-05 16:42:10,041 ELK-13367  elkm1_lib.elk      ERROR    elk:_got_data: Invalid message '0AZC2¼220040'
Traceback (most recent call last):
  File "/var/polyglot/.local/lib/python3.8/site-packages/elkm1_lib/message.py", line 67, in decode
    self.call_handlers(cmd, decoder(msg))
  File "/var/polyglot/.local/lib/python3.8/site-packages/elkm1_lib/message.py", line 290, in _zc_decode
    return {"zone_number": int(msg[4:7]) - 1, "zone_status": status}
ValueError: invalid literal for int() with base 10: '2¼2'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/var/polyglot/.local/lib/python3.8/site-packages/elkm1_lib/elk.py", line 139, in _got_data
    self._message_decode.decode(data)
  File "/var/polyglot/.local/lib/python3.8/site-packages/elkm1_lib/message.py", line 69, in decode
    raise ValueError("Cannot decode message") from exc
ValueError: Cannot decode message

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
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Versions (please complete the following information):

• ElkM1 version: [1.0.0]
• Home Assistant version: [N/A]

Additional context
Add any other context about the problem here.

[gwww]

Well that is interesting! Does it happen all the time? Do you have a guess as to what zone you think it is?

I did a couple of quick checks. ¼ is hex BC or decimal 188. The checksum and length on the message are correct, which means that the Elk panel sent this bad message -- I don't see how the lib could have messed up the message. What version of the Elk software on you running on the panel? This is a Elk panel bug, so fix will have to come from them.

The lib could be smarter with guards on decoding. Something I will consider, but it won't help you either way.

[gwww]

I just took another look at the code. Looks like there are enough guards already there - I catch the ValueError and print the message of "Cannot decode...". So nothing for me to do with the lib as far as I can tell.

If you figure it out, I'd love to hear the cause of this from the panel.