fix (or at least hack around) the "exec() causes double start() invocation" problem

servicejob.cpp

@@ -44,8 +44,15 @@ void ServiceJobPrivate::preventAutoStart()
 void ServiceJobPrivate::autoStart()
 {
     if (m_allowAutoStart) {
+        m_allowAutoStart = false;
+
+        if (q->isAutoDelete()) {
+            // by checking for isAutoDelete, we prevent autostarting when
+            // exec() is called or when the job owner has "taken control"
+            // of the job by requesting it not be autodeleted
             q->start();
         }
+    }
 }
 
 ServiceJob::ServiceJob(const QString &destination, const QString &operation,