Index: /trunk/src/VBox/ValidationKit/testmanager/batch/virtual_test_sheriff.py
===================================================================
--- /trunk/src/VBox/ValidationKit/testmanager/batch/virtual_test_sheriff.py	(revision 64945)
+++ /trunk/src/VBox/ValidationKit/testmanager/batch/virtual_test_sheriff.py	(revision 64946)
@@ -748,6 +748,4 @@
                             len(sVgaText)   if sVgaText is not None else 0,
                             len(sInfoText)  if sInfoText is not None else 0, ));
-            if sVMLog is None:
-                sVMLog = '';
 
             #self.dprint(u'main.log<<<\n%s\n<<<\n' % (sResultLog,));
@@ -789,5 +787,5 @@
             fFoundSomething = False;
             for fStopOnHit, tReason, sNeedle in self.katSimpleMainAndVmLogReasons:
-                if sResultLog.find(sNeedle) > 0 or sVMLog.find(sNeedle) > 0:
+                if sResultLog.find(sNeedle) > 0 or (sVMLog is not None and sVMLog.find(sNeedle) > 0):
                     oCaseFile.noteReasonForId(tReason, oFailedResult.idTestResult);
                     if fStopOnHit:
@@ -826,8 +824,9 @@
             # Check for repeated reboots...
             #
-            cResets = sVMLog.count('Changing the VM state from \'RUNNING\' to \'RESETTING\'');
-            if cResets > 10:
-                return oCaseFile.noteReasonForId(self.ktReason_Unknown_Reboot_Loop, oFailedResult.idTestResult,
-                                                 sComment = 'Counted %s reboots' % (cResets,));
+            if sVMLog is not None:
+                cResets = sVMLog.count('Changing the VM state from \'RUNNING\' to \'RESETTING\'');
+                if cResets > 10:
+                    return oCaseFile.noteReasonForId(self.ktReason_Unknown_Reboot_Loop, oFailedResult.idTestResult,
+                                                     sComment = 'Counted %s reboots' % (cResets,));
 
             return fFoundSomething;