src/java.base/share/classes/java/io/DataInputStream.java

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 1994, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1994, 2019, 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

@@ -48,10 +48,13 @@
      *
      * @param  in   the specified input stream
      */
     public DataInputStream(InputStream in) {
         super(in);
+        if (in == null) {
+            throw new NullPointerException();
+        } 
     }
 
     /**
      * working arrays initialized on demand by readUTF
      */