--- a/jdk/src/java.base/share/classes/sun/nio/ch/SelectorImpl.java	Fri Aug 04 10:54:48 2017 +0100
+++ b/jdk/src/java.base/share/classes/sun/nio/ch/SelectorImpl.java	Fri Aug 04 15:28:32 2017 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2017, 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
@@ -26,10 +26,18 @@
 package sun.nio.ch;
 
 import java.io.IOException;
-import java.nio.channels.*;
-import java.nio.channels.spi.*;
 import java.net.SocketException;
-import java.util.*;
+import java.nio.channels.ClosedSelectorException;
+import java.nio.channels.IllegalSelectorException;
+import java.nio.channels.SelectionKey;
+import java.nio.channels.Selector;
+import java.nio.channels.spi.AbstractSelectableChannel;
+import java.nio.channels.spi.AbstractSelector;
+import java.nio.channels.spi.SelectorProvider;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Set;
 
 
 /**
@@ -54,23 +62,18 @@
         super(sp);
         keys = new HashSet<>();
         selectedKeys = new HashSet<>();
-        if (Util.atBugLevel("1.4")) {
-            publicKeys = keys;
-            publicSelectedKeys = selectedKeys;
-        } else {
-            publicKeys = Collections.unmodifiableSet(keys);
-            publicSelectedKeys = Util.ungrowableSet(selectedKeys);
-        }
+        publicKeys = Collections.unmodifiableSet(keys);
+        publicSelectedKeys = Util.ungrowableSet(selectedKeys);
     }
 
     public Set<SelectionKey> keys() {
-        if (!isOpen() && !Util.atBugLevel("1.4"))
+        if (!isOpen())
             throw new ClosedSelectorException();
         return publicKeys;
     }
 
     public Set<SelectionKey> selectedKeys() {
-        if (!isOpen() && !Util.atBugLevel("1.4"))
+        if (!isOpen())
             throw new ClosedSelectorException();
         return publicSelectedKeys;
     }

--- a/jdk/src/java.base/share/classes/sun/nio/ch/Util.java	Fri Aug 04 10:54:48 2017 +0100
+++ b/jdk/src/java.base/share/classes/sun/nio/ch/Util.java	Fri Aug 04 15:28:32 2017 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2017, 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
@@ -25,13 +25,16 @@
 
 package sun.nio.ch;
 
-import java.lang.reflect.*;
 import java.io.FileDescriptor;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
 import java.nio.ByteBuffer;
 import java.nio.MappedByteBuffer;
 import java.security.AccessController;
 import java.security.PrivilegedAction;
-import java.util.*;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.Set;
 import jdk.internal.misc.Unsafe;
 import sun.security.action.GetPropertyAction;
 
@@ -456,21 +459,4 @@
         }
         return dbb;
     }
-
-
-    // -- Bug compatibility --
-
-    private static volatile String bugLevel;
-
-    static boolean atBugLevel(String bl) {              // package-private
-        if (bugLevel == null) {
-            if (!jdk.internal.misc.VM.isBooted())
-                return false;
-            String value = GetPropertyAction
-                    .privilegedGetProperty("sun.nio.ch.bugLevel");
-            bugLevel = (value != null) ? value : "";
-        }
-        return bugLevel.equals(bl);
-    }
-
 }

--- a/jdk/test/java/nio/channels/Selector/KeySets.java	Fri Aug 04 10:54:48 2017 +0100
+++ b/jdk/test/java/nio/channels/Selector/KeySets.java	Fri Aug 04 15:28:32 2017 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2017, 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
@@ -26,34 +26,25 @@
  * @summary Check various properties of key and selected-key sets
  *
  * @run main KeySets
- * @run main/othervm -Dsun.nio.ch.bugLevel=1.4 KeySets
  */
 
 import java.io.*;
 import java.nio.channels.*;
 import java.util.*;
 
-
 public class KeySets {
 
-    static boolean compat;
-
     static abstract class Catch {
         abstract void go() throws Exception;
         Catch(Class xc) throws Exception {
             try {
                 go();
             } catch (Exception x) {
-                if (compat)
-                    throw new Exception("Exception thrown", x);
                 if (xc.isInstance(x))
                     return;
                 throw new Exception("Wrong exception", x);
             }
-            if (compat)
-                return;
-            throw new Exception("Not thrown as expected: "
-                                + xc.getName());
+            throw new Exception("Not thrown as expected: " + xc.getName());
         }
     }
 
@@ -74,7 +65,6 @@
                 void go() throws Exception {
                     sel.selectedKeys();
                 }};
-
     }
 
     static void testNoAddition(final Set s) throws Exception {
@@ -174,14 +164,10 @@
         sel.selectedKeys().clear();
         if (!sel.selectedKeys().isEmpty())
             throw new Exception("clear failed");
-
     }
 
     public static void main(String[] args) throws Exception {
-        String bl = System.getProperty("sun.nio.ch.bugLevel");
-        compat = (bl != null) && bl.equals("1.4");
         testClose();
         testMutability();
     }
-
 }