--- a/jdk/src/java.prefs/share/classes/java/util/prefs/Preferences.java	Thu Mar 12 09:39:48 2015 -0700
+++ b/jdk/src/java.prefs/share/classes/java/util/prefs/Preferences.java	Thu Feb 12 12:56:48 2015 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2015, 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
@@ -489,6 +489,8 @@
      *       <tt>MAX_VALUE_LENGTH</tt>.
      * @throws IllegalStateException if this node (or an ancestor) has been
      *         removed with the {@link #removeNode()} method.
+     * @throws IllegalArgumentException if either the key or the value contain
+     *         the null control character, code point U+0000.
      */
     public abstract void put(String key, String value);
 

--- a/jdk/src/java.prefs/unix/classes/java/util/prefs/FileSystemPreferences.java	Thu Mar 12 09:39:48 2015 -0700
+++ b/jdk/src/java.prefs/unix/classes/java/util/prefs/FileSystemPreferences.java	Thu Feb 12 12:56:48 2015 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2015, 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
@@ -49,6 +49,13 @@
  */
 class FileSystemPreferences extends AbstractPreferences {
 
+    /**
+     * The code point U+0000, assigned to the null control character, is the
+     * only character encoded in Unicode and ISO/IEC 10646 that is always
+     * invalid in any XML 1.0 and 1.1 document.
+     */
+    private static final String CODE_POINT_U0000 = String.valueOf('\u0000');
+
     static {
         PrivilegedAction<Void> load = () -> {
             System.loadLibrary("prefs");
@@ -525,6 +532,11 @@
     }
 
     protected void putSpi(String key, String value) {
+        if (key.indexOf(CODE_POINT_U0000) != -1) {
+            throw new IllegalArgumentException("Key contains code point U+0000");
+        } else if (value.indexOf(CODE_POINT_U0000) != -1) {
+            throw new IllegalArgumentException("Value contains code point U+0000");
+        }
         initCacheIfNecessary();
         changeLog.add(new Put(key, value));
         prefsCache.put(key, value);

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/util/prefs/CodePointZeroPrefsTest.java	Thu Feb 12 12:56:48 2015 -0800
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2015, 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.
+ */
+import java.lang.reflect.Constructor;
+import java.util.prefs.Preferences;
+import java.util.prefs.PreferencesFactory;
+
+/*
+ * @test
+ * @bug 8068373
+ * @summary Ensure writing a code point U+0000 null control character is detected.
+ */
+public class CodePointZeroPrefsTest
+{
+    public static void main(String[] args) throws Exception
+    {
+        int failures = 0;
+
+        // Deliberately reflect so you can reproduce it on any platform.
+        Constructor<? extends PreferencesFactory> constructor =
+            Class.forName("java.util.prefs.FileSystemPreferencesFactory").asSubclass(PreferencesFactory.class).getDeclaredConstructor();
+        constructor.setAccessible(true);
+        PreferencesFactory factory = constructor.newInstance();
+
+        Preferences node = factory.userRoot().node("com/acme/testing");
+
+        // legal key and value
+        try {
+            node.put("a", "1");
+        } catch (IllegalArgumentException iae) {
+            System.err.println("Unexpected IllegalArgumentException for legal key");
+            failures++;
+        }
+
+        // illegal key only
+        int numIAEs = 0;
+        try {
+            node.put("a\u0000b", "1");
+            System.err.println("IllegalArgumentException not thrown for illegal key");
+            failures++;
+        } catch (IllegalArgumentException iae) {
+            // do nothing
+        }
+
+        // illegal value only
+        numIAEs = 0;
+        try {
+            node.put("ab", "2\u00003");
+            System.err.println("IllegalArgumentException not thrown for illegal value");
+            failures++;
+        } catch (IllegalArgumentException iae) {
+            // do nothing
+        }
+
+        // illegal key and value
+        numIAEs = 0;
+        try {
+            node.put("a\u0000b", "2\u00003");
+            System.err.println("IllegalArgumentException not thrown for illegal entry");
+            failures++;
+        } catch (IllegalArgumentException iae) {
+            // do nothing
+        }
+
+        if (failures != 0) {
+            throw new RuntimeException("CodePointZeroPrefsTest failed with "
+                + failures + " errors!");
+        }
+    }
+}