QProcess does not discard buffered data, writes them to new process after start()

    // think that this is server process and it dies while communicating
    qDebug() << "-- server #0 starting --";
    proc.start("sleep 0.1");
    proc.waitForStarted();
    for (int i = 0; i < 10000; i++)  // large enough to make them buffered
        proc.write("hello world\n");
    proc.waitForFinished();

    // remainder of IPC message is still kept in write buffer of QProcess.
    // main process want to discard it, but it seems not possible.
    qDebug() << "-- server #0 died --";
    qDebug() << "error:" << proc.error() << "(4: WriteError)";
    qDebug() << "bytesToWrite:" << proc.bytesToWrite();
    proc.close();
    qDebug() << "bytesToWrite (after close):" << proc.bytesToWrite();

    // main process notices the server died, so restarts it. the new server
    // process receives the remainder of the last message, which would cause
    // sort of communication protocol error.
    qDebug() << "-- server #1 starting --";
    proc.start("wc -c");
    proc.waitForStarted();
    proc.closeWriteChannel();
    proc.waitForFinished();
    qDebug() << "received:" << proc.readLine() << "[bytes]";