--- a/hotspot/src/share/vm/gc/shared/taskqueue.cpp	Tue Sep 01 14:01:18 2015 -0700
+++ b/hotspot/src/share/vm/gc/shared/taskqueue.cpp	Wed Sep 02 09:14:04 2015 +0200
@@ -258,8 +258,8 @@
 
 #ifdef ASSERT
 bool ObjArrayTask::is_valid() const {
-  return _obj != NULL && _obj->is_objArray() && _index > 0 &&
-    _index < objArrayOop(_obj)->length();
+  return _obj != NULL && _obj->is_objArray() && _index >= 0 &&
+      _index < objArrayOop(_obj)->length();
 }
 #endif // ASSERT