--- a/src/java.base/share/classes/java/net/ServerSocket.java	Tue May 07 16:06:10 2019 +0200
+++ b/src/java.base/share/classes/java/net/ServerSocket.java	Tue May 07 15:39:33 2019 +0100
@@ -32,6 +32,7 @@
 import java.nio.channels.ServerSocketChannel;
 import java.security.AccessController;
 import java.security.PrivilegedExceptionAction;
+import java.util.Objects;
 import java.util.Set;
 import java.util.Collections;
 
@@ -81,6 +82,7 @@
      * @since 12
      */
     protected ServerSocket(SocketImpl impl) {
+        Objects.requireNonNull(impl);
         this.impl = impl;
     }
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/net/ServerSocket/NullConstructor.java	Tue May 07 15:39:33 2019 +0100
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 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.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @bug 8223457
+ * @run main NullConstructor
+ * @summary java.net.ServerSocket protected constructor should throw NPE if impl null
+ */
+
+import java.net.ServerSocket;
+import java.net.SocketImpl;
+
+public class NullConstructor {
+
+    public static void main(String args[]) throws Exception {
+        try {
+            ServerSocket server = new ServerSocket((SocketImpl)null) {};
+            throw new RuntimeException("Test failed");
+        } catch (NullPointerException ee) {}
+    }
+}