When opening connection QWebSocket sometimes hang up during handshake in QWebSocketPrivate::processData() due to the bad while condition: m_pSocket->bytesAvailable() is true but m_pSocket->canReadLine() is false, so processHandshake do nothing in state ReadingStatusState.

Bug fix, that is worked for me, would be adding single line - to break while during handshake if we can't read a line, because processHandshake reads only lines (all auto tests passed with this fix):

File: qwebsocket_p.cpp

void QWebSocketPrivate::processData()
{
    Q_ASSERT(m_pSocket);
    while (m_pSocket->bytesAvailable()) {
        if (state() == QAbstractSocket::ConnectingState) {
            if (!m_pSocket->canReadLine()) break; // <-- bug fix
            processHandshake(m_pSocket);
        } else {
            m_dataProcessor.process(m_pSocket);
        }
    }
}