invalid utf-8 payload

[Oncl3joe]

Hi Miguel,

When sending message with special chars from client to server, socket-io throw an exception :

Traceback (most recent call last):
  File "/var/www/.pyenv/versions/3.6.1/lib/python3.6/site-packages/engineio/server.py", line 279, in handle_request
    socket.handle_post_request(environ)
  File "/var/www/.pyenv/versions/3.6.1/lib/python3.6/site-packages/engineio/socket.py", line 104, in handle_post_request
    p = payload.Payload(encoded_payload=body)
  File "/var/www/.pyenv/versions/3.6.1/lib/python3.6/site-packages/engineio/payload.py", line 11, in __init__
    self.decode(encoded_payload)
  File "/var/www/.pyenv/versions/3.6.1/lib/python3.6/site-packages/engineio/payload.py", line 58, in decode
    raise ValueError('invalid payload')
ValueError: invalid payload

My javascript code :

var socket = io.connect("http://XXX:XXX", {transports:["polling"]});
socket.emit("my_event", {"data": "ééé"});

I try to modify "payload.py", and i find an exception on this line :
fixed_payload = encoded_payload.decode('utf-8').encode('raw_unicode_escape')

"encoded_payload" isn't decoded because an exception was throw. Adding encoded_payload = encoded_payload.decode('utf-8') in the except block resolve my problem, but i think it's not the best solution.

Python version : Python 3.6.1
Javascript Socket-IO version : 2.0.1

Python packages :
Flask==0.12.1
Flask-SocketIO==2.8.6
python-engineio==1.5.2
python-socketio==1.7.4
eventlet==0.21.0

[miguelgrinberg]

That line that is failing was added there to compensate for a bug in a few releases of the Socket.IO JavaScript client. They have probably changed the client in the 2.x that causes things to break in a different way. I'll have to see what I can figure out to keep this fix for the 1.x socket.io clients, while allowing the 2.x to work as well.