tdeio - scheduler: Fix crash if the job or slave are not valid.

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>
(cherry picked from commit e22af1c0a0)

tdeio/tdeio/scheduler.cpp

@@ -796,6 +796,18 @@ Scheduler::_assignJobToSlave(TDEIO::Slave *slave, SimpleJob *job)
 {
 //    kdDebug(7006) << "_assignJobToSlave( " << job << ", " << slave << ")" << endl;
     TQString dummy;
+    if (!job)
+    {
+        kdDebug(7006) << "_assignJobToSlave(): ERROR, non-existing job." << endl;
+        return false;
+    }
+    if (!slave)
+    {
+        kdDebug(7006) << "_assignJobToSlave(): ERROR, non-existing slave." << endl;
+        job->kill();
+        return false;
+    }
+
     if ((slave->slaveProtocol() != KProtocolManager::slaveProtocol( job->url(), dummy ))
         ||
         (!newJobs.removeRef(job)))