8068741: javax.script.ScriptEngineFactory.getMethodCallSyntax() spec allows null passed as an object

Reviewed-by: hannesw

src/java.scripting/share/classes/javax/script/ScriptEngineFactory.java

@@ -176,6 +176,8 @@ public interface ScriptEngineFactory {
      * @param args names of the arguments in the method call.
      *
      * @return The String used to invoke the method in the syntax of the scripting language.
+     *
+     * @throws NullPointerException if obj or m or args or any of the elements of args is null.
      */
     public String getMethodCallSyntax(String obj, String m, String... args);
 

src/jdk.scripting.nashorn/share/classes/jdk/nashorn/api/scripting/NashornScriptEngineFactory.java

@@ -76,14 +76,16 @@ public final class NashornScriptEngineFactory implements ScriptEngineFactory {
 
     @Override
     public String getMethodCallSyntax(final String obj, final String method, final String... args) {
-        final StringBuilder sb = new StringBuilder().append(obj).append('.').append(method).append('(');
+        final StringBuilder sb = new StringBuilder().
+            append(Objects.requireNonNull(obj)).append('.').
+            append(Objects.requireNonNull(method)).append('(');
         final int len = args.length;
 
         if (len > 0) {
-            sb.append(args[0]);
+            sb.append(Objects.requireNonNull(args[0]));
         }
         for (int i = 1; i < len; i++) {
-            sb.append(',').append(args[i]);
+            sb.append(',').append(Objects.requireNonNull(args[i]));
         }
         sb.append(')');
 

test/nashorn/src/jdk/nashorn/api/scripting/test/JDK_8068741_Test.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+
+package jdk.nashorn.api.scripting.test;
+
+import javax.script.ScriptEngineFactory;
+import jdk.nashorn.api.scripting.NashornScriptEngineFactory;
+import org.testng.Assert;
+import org.testng.annotations.Test;
+
+/**
+ * @test
+ * @run testng jdk.nashorn.api.scripting.test.JDK_8068741_Test
+ * @bug 8068741
+ * @summary javax.script.ScriptEngineFactory.getMethodCallSyntax() spec allows null passed as an object
+ */
+public class JDK_8068741_Test {
+    @Test
+    public void testGetMethodCallSyntax() {
+        ScriptEngineFactory fac = new NashornScriptEngineFactory();
+        checkThrowsNPE(() -> fac.getMethodCallSyntax(null, "foo"));
+        checkThrowsNPE(() -> fac.getMethodCallSyntax("obj", null));
+        checkThrowsNPE(() -> fac.getMethodCallSyntax("obj", "foo", (String[])null));
+        checkThrowsNPE(() -> fac.getMethodCallSyntax("obj", "foo", null, "xyz"));
+        checkThrowsNPE(() -> fac.getMethodCallSyntax("obj", "foo", "xyz", null));
+    }
+
+    private void checkThrowsNPE(Runnable r) {
+        boolean gotNPE = false;
+        try {
+            r.run();
+        } catch (NullPointerException npe) {
+            gotNPE = true;
+            System.err.println("Got NPE as expected: " + npe);
+        }
+        Assert.assertTrue(gotNPE);
+    }
+}