QWebSocket doesn't emit bytesWritten signal

In the attached zip file there is a modified 'echoserver' application where QWebSocket::bytesWritten signal is connected to a slot in EchoServer in EchoServer::onNewConnection. However the slot does not get called when the server echos back data written from the client. If the same modification is done to the 'SslEchoServer' application, the slot is not getting called either.

For convenience the 'echoclient' is attached also.

Steps to reproduce:
1. compile and run 'echoserver'
2. compile and run 'echoclient'

Expected result:
"number of bytes written" should be displayed in the console

Actual result:
no "number of bytes written" is not getting displayed to the console