Motivation:
According to the websocket specification peers may send a close frame when
they detect a protocol violation (with status code 1002). The current
implementation simply closes the connection. This update should add this
functionality. The functionality is optional - but it might help other
implementations with debugging when they receive such a frame.
Modification:
When a protocol violation in the decoder is detected and a close was not
already initiated by the remote peer a close frame is
sent.
Result:
Remotes which will send an invalid frame will now get a close frame that
indicates the protocol violation instead of only seeing a closed
connection.
2a5adc0b2b