Empty the buffer once the whole handshake response has been received by the client, else HTTP headers are published as messages.

lib/websocket/client_protocol.rb

@@ -67,6 +67,7 @@ module WebSocket
 
     def valid?
       data = Protocol.encode(@buffer)
+      @buffer = []
 
       response = Net::HTTPResponse.read_new(Net::BufferedIO.new(StringIO.new(data)))
       return false unless response.code.to_i == 101