/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

package org.mozilla.javascript;

class SpecialRef extends Ref
{
    private static final long serialVersionUID = -7521596632456797847L;

    private static final int SPECIAL_NONE = 0;
    private static final int SPECIAL_PROTO = 1;
    private static final int SPECIAL_PARENT = 2;

    private Scriptable target;
    private int type;
    private String name;

    private SpecialRef(Scriptable target, int type, String name)
    {
        this.target = target;
        this.type = type;
        this.name = name;
    }

    static Ref createSpecial(Context cx, Scriptable scope, Object object,
                             String name)
    {
        Scriptable target = ScriptRuntime.toObjectOrNull(cx, object, scope);
        if (target == null) {
            throw ScriptRuntime.undefReadError(object, name);
        }

        int type;
        if (name.equals("__proto__")) {
            type = SPECIAL_PROTO;
        } else if (name.equals("__parent__")) {
            type = SPECIAL_PARENT;
        } else {
            throw new IllegalArgumentException(name);
        }

        if (!cx.hasFeature(Context.FEATURE_PARENT_PROTO_PROPERTIES)) {
            // Clear special after checking for valid name!
            type = SPECIAL_NONE;
        }

        return new SpecialRef(target, type, name);
    }

    @Override
    public Object get(Context cx)
    {
        switch (type) {
          case SPECIAL_NONE:
            return ScriptRuntime.getObjectProp(target, name, cx);
          case SPECIAL_PROTO:
            return target.getPrototype();
          case SPECIAL_PARENT:
            return target.getParentScope();
          default:
            throw Kit.codeBug();
        }
    }

    @Override
    @Deprecated
    public Object set(Context cx, Object value) {
        throw new IllegalStateException();
    }

    @Override
    public Object set(Context cx, Scriptable scope, Object value)
    {
        switch (type) {
          case SPECIAL_NONE:
            return ScriptRuntime.setObjectProp(target, name, value, cx);
          case SPECIAL_PROTO:
          case SPECIAL_PARENT:
            {
                Scriptable obj = ScriptRuntime.toObjectOrNull(cx, value, scope);
                if (obj != null) {
                    // Check that obj does not contain on its prototype/scope
                    // chain to prevent cycles
                    Scriptable search = obj;
                    do {
                        if (search == target) {
                            throw Context.reportRuntimeErrorById("msg.cyclic.value", name);
                        }
                        if (type == SPECIAL_PROTO) {
                            search = search.getPrototype();
                        } else {
                            search = search.getParentScope();
                        }
                    } while (search != null);
                }
                if (type == SPECIAL_PROTO) {
                    if (target instanceof ScriptableObject
                            && !((ScriptableObject)target).isExtensible()
                            && cx.getLanguageVersion() >= Context.VERSION_1_8) {
                        throw ScriptRuntime.typeErrorById("msg.not.extensible");
                    }

                    if (cx.getLanguageVersion() >= Context.VERSION_ES6) {
                        final String typeOfValue = ScriptRuntime.typeof(value);
                        if (value == null) {
                            target.setPrototype(Undefined.SCRIPTABLE_UNDEFINED);
                            return null;
                        }

                        if (!"object".equals(typeOfValue) && !"function".equals(typeOfValue)) {
                            return value;
                        }

                        final String typeOfTarget = ScriptRuntime.typeof(target);
                        if ("object".equals(typeOfTarget) || "function".equals(typeOfTarget)) {
                            target.setPrototype(obj);
                        }
                    } else {
                        target.setPrototype(obj);
                    }
                } else {
                    target.setParentScope(obj);
                }
                return obj;
            }
          default:
            throw Kit.codeBug();
        }
    }

    @Override
    public boolean has(Context cx)
    {
        if (type == SPECIAL_NONE) {
            return ScriptRuntime.hasObjectElem(target, name, cx);
        }
        return true;
    }

    @Override
    public boolean delete(Context cx)
    {
        if (type == SPECIAL_NONE) {
            return ScriptRuntime.deleteObjectElem(target, name, cx);
        }
        return false;
    }
}

@@ -3654,21 +3654,22 @@
 g typeOf
-Value
+Target
  = Scrip
@@ -3688,16 +3688,118 @@
 eof(
-value);%0A
+target);%0A                        if (%22object%22.equals(typeOfTarget) %7C%7C %22function%22.equals(typeOfTarget)) %7B%0A%0A    
     
@@ -3831,32 +3831,36 @@
 alue == null) %7B%0A
+    
                 
@@ -3956,168 +3956,8 @@
     
-return null;%0A                        %7D%0A%0A                        if (!%22object%22.equals(typeOfValue) && !%22function%22.equals(typeOfValue)) %7B%0A                        
     
@@ -3982,39 +3982,47 @@
                 
+        %7D%0A%0A
     
-%7D%0A%0A
                 
@@ -4040,38 +4040,37 @@
 al String typeOf
-Target
+Value
  = ScriptRuntime
@@ -4073,33 +4073,36 @@
 time.typeof(
-target);%0A
+value);%0A    
             
@@ -4131,38 +4131,37 @@
 t%22.equals(typeOf
-Target
+Value
 ) %7C%7C %22function%22.
@@ -4169,30 +4169,29 @@
 quals(typeOf
-Target
+Value
 )) %7B%0A       
@@ -4203,32 +4203,36 @@
                 
+    
 target.setProtot
@@ -4257,33 +4257,101 @@
                 
-%7D
+    %7D%0A                        %7D%0A                        return value;
 %0A               

fix null handling as suggested