--- old/src/java.base/share/classes/java/io/DataOutputStream.java	2019-07-18 11:07:34.000000000 -0700
+++ new/src/java.base/share/classes/java/io/DataOutputStream.java	2019-07-18 11:07:34.000000000 -0700
@@ -58,6 +58,9 @@
      */
     public DataOutputStream(OutputStream out) {
         super(out);
+        if (out == null) {
+            throw new NullPointerException();
+        } 
     }
 
     /**