Fail the WebSocket connection on protocol error

This is correct according to the spec for invalid UTF-8 errors. The spec isn't clear for other errors (e.g. receiving a message which is too large), but failing the connection seems appropriate.

Specifically this means that we send the close code and then _close the tcp connection_. Previously there was a bug where the input stream would not be processed and therefore a close handshake ack would not be processed, leaving the connection open.

Also refactored this logic into handler

lib/em-websocket/connection.rb

@@ -76,10 +76,6 @@ def receive_data(data)
         else
           dispatch(data)
         end
-      rescue WSProtocolError => e
-        debug [:error, e]
-        trigger_on_error(e)
-        close_websocket_private(e.code, e.message)
       rescue => e
         debug [:error, e]
 

lib/em-websocket/handler.rb

@@ -44,12 +44,22 @@ def initialize(connection, debug = false)
       def receive_data(data)
         @data << data
         process_data
+      rescue WSProtocolError => e
+        fail_websocket(e)
       end
 
       def close_websocket(code, body)
         # Implemented in subclass
       end
 
+      # This corresponds to "Fail the WebSocket Connection" in the spec.
+      def fail_websocket(e)
+        debug [:error, e]
+        close_websocket(e.code, e.message)
+        @connection.close_connection_after_writing
+        @connection.trigger_on_error(e)
+      end
+
       def unbind
         @state = :closed