Problem with QProcess and "zombie" processes on Symbian

After a process has finished (QProcess::finished / waitForFinished()) the process should be closed? With 4.7.0 on Symbian S60 this is not the case. When starting a Qt console application from another Qt console application the child process seems to be in the background (as a zombie) until the parent application is closed.

This behavior causes serious problems if a parent runs constantly in the background and starts periodically different child processes. At some the Symbian OS is jammed because the process limit has been reached (e.g. 256 on E51). Here is a small example:

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    QTimer::singleShot(10000, &a, SLOT(quit()));
    return a.exec();
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    QProcess *process = new QProcess(&a);
    process->start("childprocess.exe");
    if(process->waitForStarted())
    {
        process->waitForFinished(-1);
    }
    delete process;
    return a.exec();
}

If you investigate the running processes when the main enters into event loop you can see that the child is still running in the background. When you close the main application both processes are terminated. In order to see running processes use some 3rd party task managers (e.g. YTasks: http://www.drjukka.com/YTasks.html).

Later on I'll upload some test applications and provide some additional details.