7160242: (prefs) Preferences.remove(null) does not throw NPE [macosx]

Insert null check of argument in remove()'s implementation

Reviewed-by: forax, chegar, alanb

jdk/src/macosx/classes/java/util/prefs/MacOSXPreferences.java

@@ -25,6 +25,8 @@
 
 package java.util.prefs;
 
+import java.util.Objects;
+
 class MacOSXPreferences extends AbstractPreferences {
     // fixme need security checks?
 
@@ -147,6 +149,7 @@ class MacOSXPreferences extends AbstractPreferences {
     // AbstractPreferences implementation
     protected void removeSpi(String key)
     {
+        Objects.requireNonNull(key, "Specified key cannot be null");
         file.removeKeyFromNode(path, key);
     }
 

jdk/test/java/util/prefs/RemoveNullKeyCheck.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2012, 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 7160242
+ * @summary Check if NullPointerException is thrown if the key passed
+ *          to remove() is null.
+ */
+
+import java.util.prefs.Preferences;
+
+public class RemoveNullKeyCheck {
+
+    public static void main(String[] args) throws Exception {
+       try {
+           Preferences node = Preferences.userRoot().node("N1");
+           node.remove(null);
+           throw new RuntimeException("Expected NullPointerException " +
+                                      "not thrown");
+       } catch (NullPointerException npe) {
+           System.out.println("NullPointerException thrown");
+       }
+    }
+}