Hello Everyone,

Thank you for your help. The solution was my lack of awareness on what's happening when you call QProcess::kill(). I was trying to disconnect and then reconnect my signals by calling the connect immediately after calling kill() (like in post #6 where I call blockSignals before and after the kill call.

I got the idea from fatjuicymole when he made a comment about my post #6. The process object was getting its signals reconnected before the external program had been terminated, since QProcess::kill() is not a synchronous function as it does not wait for the external function to be terminated.

Now when I press the stop button, the slot stopProcess contains the following:
Qt Code: 
  1. disconnect(process, SIGNAL(error(QProcess::ProcessError)), this, SLOT(handleProcessError(QProcess::ProcessError error)));
  2. disconnect(process, SIGNAL(finished(int, QProcess::ExitStatus )), this, SLOT(handleProcessFinish(int, QProcess::ExitStatus)));
  3. process->kill()
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and then when I press the start button I reconnect the signals, e.g.:
Qt Code: 
  1. connect(process, SIGNAL(error(QProcess::ProcessError)), this, SLOT(handleProcessError(QProcess::ProcessError error)));
  2. connect(process, SIGNAL(finished(int, QProcess::ExitStatus )), this, SLOT(handleProcessFinish(int, QProcess::ExitStatus)));
  3. process->start(processName);
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Thanks for your help everyone. The problem, like usual, ended up being the user. You learn something new everyday, even though you realize that you should've known it anyways