check_for_messages res evaluates to 49 or 50

[Beormund]

Thanks for a great async MQTT implementation. I particularly like the decoupling from wifi/networking. I have got this working nicely on a RP Pico W connecting to Mosquitto. I had a slight issue on connecting. The on_connection_cb kept firing repeatedly in connect(). It was due to message_handler() -> check_for_messages() setting is_connected to False when res = 49 or 50. This in turn causes keep_alive_task to break out of the while loop. I simply removed:

umqtt_async/umqtt_async/umqtt_async.py

Lines 320 to 321 in 18004ae

	else:
	raise OSError(-1)

I'm not sure what codes 49 or 50 are??

umqtt_async/umqtt_async/umqtt_async.py

Lines 229 to 230 in 18004ae

	self.loop.create_task(self.message_handler()) # Tasks quit on connection fail.
	self.loop.create_task(self.keep_alive_task())

->

umqtt_async/umqtt_async/umqtt_async.py

Lines 329 to 335 in 18004ae

	async def message_handler(self):
	try:
	while self.is_connected:
	await self.check_for_message()
	except OSError:
	pass
	self.is_connected = False

->

umqtt_async/umqtt_async/umqtt_async.py

Lines 240 to 244 in 18004ae

	res = await self.read(1)
	if res == b'':
	return None
	res = res[0]

# res = 49 or 50

->

umqtt_async/umqtt_async/umqtt_async.py

Lines 320 to 321 in 18004ae

	else:
	raise OSError(-1)

->

umqtt_async/umqtt_async/umqtt_async.py

Lines 338 to 346 in 18004ae

	async def keep_alive_task(self):
	while self.is_connected:
	if ticks_diff(ticks_ms(), self.last_message_received) >= (self.keep_alive*1000/2):
	try:
	await self.ping()
	except OSError:
	break
	await asyncio.sleep(1)
	self.is_connected = False