handle NPE when a host does not have any VMs

Author: DaanHoogland

vmware-base/src/main/java/com/cloud/hypervisor/vmware/mo/BaseMO.java

@@ -33,6 +33,7 @@
 import com.vmware.vim25.RetrieveResult;
 
 import java.lang.reflect.InvocationTargetException;
+import java.util.ArrayList;
 import java.util.List;
 
 public class BaseMO {
@@ -65,6 +66,9 @@ protected static Pair<String, List<ObjectContent>> createReturnObjectPair(Retrie
         if (s_logger.isDebugEnabled()) {
             s_logger.debug("vmware result : " + ReflectionToStringBuilderUtils.reflectCollection(result));
         }
+        if (result == null) {
+            return new Pair<>(null, new ArrayList<>());
+        }
         String tokenForRetrievingNewResults = result.getToken();
         List<ObjectContent> listOfObjects = result.getObjects();
         return new Pair<>(tokenForRetrievingNewResults, listOfObjects);