src/jdk.jdi/share/classes/com/sun/tools/jdi/MethodImpl.java

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this

@@ -313,14 +313,15 @@
             ArrayReference argArray = lastParamType.newInstance(0);
             arguments.add(argArray);
             return;
         }
         Value nthArgValue = arguments.get(paramCount - 1);
-        if (nthArgValue == null) {
+        if (nthArgValue == null && argCount == paramCount) {
+            // The only one varargs parameter is null
             return;
         }
-        Type nthArgType = nthArgValue.type();
+        Type nthArgType = (nthArgValue == null) ? null : nthArgValue.type();
         if (nthArgType instanceof ArrayTypeImpl) {
             if (argCount == paramCount &&
                 ((ArrayTypeImpl)nthArgType).isAssignableTo(lastParamType)) {
                 /*
                  * This is case 1.  A compatible array is being passed to the