8022598: Object.getPrototypeOf should return null for host objects rather than throwing TypeError

Reviewed-by: lagergren, jlaskey, attila, hannesw

nashorn/src/jdk/nashorn/internal/objects/NativeObject.java

@@ -113,6 +113,13 @@ public final class NativeObject {
         } else if (obj instanceof ScriptObjectMirror) {
             return ((ScriptObjectMirror)obj).getProto();
         } else {
+            final JSType type = JSType.of(obj);
+            if (type == JSType.OBJECT) {
+                // host (Java) objects have null __proto__
+                return null;
+            }
+
+            // must be some JS primitive
             throw notAnObject(obj);
         }
     }

nashorn/test/script/basic/JDK-8022598.js

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2010, 2013, 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.
+ */
+
+/**
+ * JDK-8022598: Object.getPrototypeOf should return null for host objects rather than throwing TypeError
+ *
+ * @test
+ * @run
+ */
+
+// the following should not throw TypeError, just return null instead
+
+var proto = Object.getPrototypeOf(new java.lang.Object());
+if (proto !== null) {
+    fail("Expected 'null' __proto__ for host objects");
+}
+
+// on primitive should result in TypeError
+
+function checkTypeError(obj) {
+    try {
+        Object.getPrototypeOf(obj);
+        fail("Expected TypeError for Object.getPrototypeOf on " + obj);
+    } catch (e) {
+        if (! (e instanceof TypeError)) {
+            fail("Expected TypeError, but got " + e);
+        }
+    }
+}
+
+checkTypeError(undefined);
+checkTypeError(null);
+checkTypeError(3.1415);
+checkTypeError("hello");
+checkTypeError(false);
+checkTypeError(true);