--- a/nashorn/src/jdk/nashorn/internal/objects/NativeJava.java	Fri Sep 13 17:50:18 2013 +0530
+++ b/nashorn/src/jdk/nashorn/internal/objects/NativeJava.java	Mon Sep 16 15:08:36 2013 +0530
@@ -34,6 +34,7 @@
 import java.util.List;
 import jdk.internal.dynalink.beans.StaticClass;
 import jdk.internal.dynalink.support.TypeUtilities;
+import jdk.nashorn.api.scripting.JSObject;
 import jdk.nashorn.internal.objects.annotations.Attribute;
 import jdk.nashorn.internal.objects.annotations.Function;
 import jdk.nashorn.internal.objects.annotations.ScriptClass;
@@ -43,6 +44,7 @@
 import jdk.nashorn.internal.runtime.ListAdapter;
 import jdk.nashorn.internal.runtime.PropertyMap;
 import jdk.nashorn.internal.runtime.ScriptObject;
+import jdk.nashorn.internal.runtime.ScriptRuntime;
 import jdk.nashorn.internal.runtime.linker.Bootstrap;
 import jdk.nashorn.internal.runtime.linker.JavaAdapterFactory;
 
@@ -288,7 +290,9 @@
             return null;
         }
 
-        Global.checkObject(obj);
+        if (!(obj instanceof ScriptObject) && !(obj instanceof JSObject)) {
+            throw typeError("not.an.object", ScriptRuntime.safeToString(obj));
+        }
 
         final Class<?> targetClass;
         if(objType == UNDEFINED) {
@@ -304,11 +308,11 @@
         }
 
         if(targetClass.isArray()) {
-            return ((ScriptObject)obj).getArray().asArrayOfType(targetClass.getComponentType());
+            return JSType.toJavaArray(obj, targetClass.getComponentType());
         }
 
         if(targetClass == List.class || targetClass == Deque.class) {
-            return new ListAdapter((ScriptObject)obj);
+            return ListAdapter.create(obj);
         }
 
         throw typeError("unsupported.java.to.type", targetClass.getName());

--- a/nashorn/src/jdk/nashorn/internal/runtime/ECMAErrors.java	Fri Sep 13 17:50:18 2013 +0530
+++ b/nashorn/src/jdk/nashorn/internal/runtime/ECMAErrors.java	Mon Sep 16 15:08:36 2013 +0530
@@ -28,7 +28,6 @@
 import java.text.MessageFormat;
 import java.util.Locale;
 import java.util.ResourceBundle;
-
 import jdk.nashorn.api.scripting.NashornException;
 import jdk.nashorn.internal.scripts.JS;
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/src/jdk/nashorn/internal/runtime/JSObjectListAdapter.java	Mon Sep 16 15:08:36 2013 +0530
@@ -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.  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.internal.runtime;
+
+import jdk.nashorn.api.scripting.JSObject;
+
+/**
+ * A ListAdapter that can wraps a JSObject.
+ */
+public final class JSObjectListAdapter extends ListAdapter {
+    /**
+     * Creates a new list wrapper for the specified JSObject.
+     * @param obj JSOcript the object to wrap
+     */
+    public JSObjectListAdapter(final JSObject obj) {
+        super(obj);
+    }
+
+    @Override
+    public int size() {
+        return JSType.toInt32(((JSObject)obj).getMember("length"));
+    }
+
+    @Override
+    protected Object getAt(int index) {
+        return ((JSObject)obj).getSlot(index);
+    }
+
+    @Override
+    protected void setAt(int index, Object element) {
+        ((JSObject)obj).setSlot(index, element);
+    }
+}

--- a/nashorn/src/jdk/nashorn/internal/runtime/JSType.java	Fri Sep 13 17:50:18 2013 +0530
+++ b/nashorn/src/jdk/nashorn/internal/runtime/JSType.java	Mon Sep 16 15:08:36 2013 +0530
@@ -28,10 +28,14 @@
 import static jdk.nashorn.internal.codegen.CompilerConstants.staticCall;
 import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;
 
+import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
+import java.lang.reflect.Array;
 import jdk.internal.dynalink.beans.StaticClass;
+import jdk.nashorn.api.scripting.JSObject;
 import jdk.nashorn.internal.codegen.CompilerConstants.Call;
 import jdk.nashorn.internal.parser.Lexer;
+import jdk.nashorn.internal.runtime.arrays.ArrayLikeIterator;
 import jdk.nashorn.internal.runtime.linker.Bootstrap;
 
 /**
@@ -860,6 +864,53 @@
     }
 
     /**
+     * Script object to Java array conversion.
+     *
+     * @param obj script object to be converted to Java array
+     * @param componentType component type of the destination array required
+     * @return converted Java array
+     */
+    public static Object toJavaArray(final Object obj, final Class<?> componentType) {
+        if (obj instanceof ScriptObject) {
+            return convertArray(((ScriptObject)obj).getArray().asObjectArray(), componentType);
+        } else if (obj instanceof JSObject) {
+            final ArrayLikeIterator itr = ArrayLikeIterator.arrayLikeIterator(obj);
+            final int len = (int) itr.getLength();
+            final Object[] res = new Object[len];
+            int idx = 0;
+            while (itr.hasNext()) {
+                res[idx++] = itr.next();
+            }
+            return convertArray(res, componentType);
+        } else {
+            throw new IllegalArgumentException("not a script object");
+        }
+    }
+
+    /**
+     * Java array to java array conversion - but using type conversions implemented by linker.
+     *
+     * @param src source array
+     * @param componentType component type of the destination array required
+     * @return converted Java array
+     */
+    public static Object convertArray(final Object[] src, final Class<?> componentType) {
+        final int l = src.length;
+        final Object dst = Array.newInstance(componentType, l);
+        final MethodHandle converter = Bootstrap.getLinkerServices().getTypeConverter(Object.class, componentType);
+        try {
+            for (int i = 0; i < src.length; i++) {
+                Array.set(dst, i, invoke(converter, src[i]));
+            }
+        } catch (final RuntimeException | Error e) {
+            throw e;
+        } catch (final Throwable t) {
+            throw new RuntimeException(t);
+        }
+        return dst;
+    }
+
+    /**
      * Check if an object is null or undefined
      *
      * @param obj object to check
@@ -964,4 +1015,13 @@
         return Double.NaN;
     }
 
+    private static Object invoke(final MethodHandle mh, final Object arg) {
+        try {
+            return mh.invoke(arg);
+        } catch (final RuntimeException | Error e) {
+            throw e;
+        } catch (final Throwable t) {
+            throw new RuntimeException(t);
+        }
+    }
 }

--- a/nashorn/src/jdk/nashorn/internal/runtime/ListAdapter.java	Fri Sep 13 17:50:18 2013 +0530
+++ b/nashorn/src/jdk/nashorn/internal/runtime/ListAdapter.java	Mon Sep 16 15:08:36 2013 +0530
@@ -32,6 +32,7 @@
 import java.util.NoSuchElementException;
 import java.util.RandomAccess;
 import java.util.concurrent.Callable;
+import jdk.nashorn.api.scripting.JSObject;
 import jdk.nashorn.internal.runtime.linker.Bootstrap;
 import jdk.nashorn.internal.runtime.linker.InvokeByName;
 
@@ -48,7 +49,7 @@
  * operations respectively, while {@link #addLast(Object)} and {@link #removeLast()} will translate to {@code push} and
  * {@code pop}.
  */
-public final class ListAdapter extends AbstractList<Object> implements RandomAccess, Deque<Object> {
+public abstract class ListAdapter extends AbstractList<Object> implements RandomAccess, Deque<Object> {
     // These add to the back and front of the list
     private static final Object PUSH    = new Object();
     private static InvokeByName getPUSH() {
@@ -56,7 +57,7 @@
                 new Callable<InvokeByName>() {
                     @Override
                     public InvokeByName call() {
-                        return new InvokeByName("push", ScriptObject.class, void.class, Object.class);
+                        return new InvokeByName("push", Object.class, void.class, Object.class);
                     }
                 });
     }
@@ -67,7 +68,7 @@
                 new Callable<InvokeByName>() {
                     @Override
                     public InvokeByName call() {
-                        return new InvokeByName("unshift", ScriptObject.class, void.class, Object.class);
+                        return new InvokeByName("unshift", Object.class, void.class, Object.class);
                     }
                 });
     }
@@ -79,7 +80,7 @@
                 new Callable<InvokeByName>() {
                     @Override
                     public InvokeByName call() {
-                        return new InvokeByName("pop", ScriptObject.class, Object.class);
+                        return new InvokeByName("pop", Object.class, Object.class);
                     }
                 });
     }
@@ -90,7 +91,7 @@
                 new Callable<InvokeByName>() {
                     @Override
                     public InvokeByName call() {
-                        return new InvokeByName("shift", ScriptObject.class, Object.class);
+                        return new InvokeByName("shift", Object.class, Object.class);
                     }
                 });
     }
@@ -102,7 +103,7 @@
                 new Callable<InvokeByName>() {
                     @Override
                     public InvokeByName call() {
-                        return new InvokeByName("splice", ScriptObject.class, void.class, int.class, int.class, Object.class);
+                        return new InvokeByName("splice", Object.class, void.class, int.class, int.class, Object.class);
                     }
                 });
     }
@@ -113,40 +114,52 @@
                 new Callable<InvokeByName>() {
                     @Override
                     public InvokeByName call() {
-                        return new InvokeByName("splice", ScriptObject.class, void.class, int.class, int.class);
+                        return new InvokeByName("splice", Object.class, void.class, int.class, int.class);
                     }
                 });
     }
 
-    private final ScriptObject obj;
+    protected final Object obj;
 
-    /**
-     * Creates a new list wrapper for the specified script object.
-     * @param obj script the object to wrap
-     */
-    public ListAdapter(ScriptObject obj) {
+    // allow subclasses only in this package
+    ListAdapter(Object obj) {
         this.obj = obj;
     }
 
-    @Override
-    public int size() {
-        return JSType.toInt32(obj.getLength());
+    /**
+     * Factory to create a ListAdapter for a given script object.
+     *
+     * @param obj script object to wrap as a ListAdapter
+     * @return A ListAdapter wrapper object
+     */
+    public static ListAdapter create(final Object obj) {
+        if (obj instanceof ScriptObject) {
+            return new ScriptObjectListAdapter((ScriptObject)obj);
+        } else if (obj instanceof JSObject) {
+            return new JSObjectListAdapter((JSObject)obj);
+        } else {
+            throw new IllegalArgumentException("ScriptObject or JSObject expected");
+        }
     }
 
     @Override
-    public Object get(int index) {
+    public final Object get(int index) {
         checkRange(index);
-        return obj.get(index);
+        return getAt(index);
     }
 
+    protected abstract Object getAt(final int index);
+
     @Override
     public Object set(int index, Object element) {
         checkRange(index);
-        final Object prevValue = get(index);
-        obj.set(index, element, false);
+        final Object prevValue = getAt(index);
+        setAt(index, element);
         return prevValue;
     }
 
+    protected abstract void setAt(int index, Object element);
+
     private void checkRange(int index) {
         if(index < 0 || index >= size()) {
             throw invalidIndex(index);
@@ -154,18 +167,18 @@
     }
 
     @Override
-    public void push(Object e) {
+    public final void push(Object e) {
         addFirst(e);
     }
 
     @Override
-    public boolean add(Object e) {
+    public final boolean add(Object e) {
         addLast(e);
         return true;
     }
 
     @Override
-    public void addFirst(Object e) {
+    public final void addFirst(Object e) {
         try {
             final InvokeByName unshiftInvoker = getUNSHIFT();
             final Object fn = unshiftInvoker.getGetter().invokeExact(obj);
@@ -179,7 +192,7 @@
     }
 
     @Override
-    public void addLast(Object e) {
+    public final void addLast(Object e) {
         try {
             final InvokeByName pushInvoker = getPUSH();
             final Object fn = pushInvoker.getGetter().invokeExact(obj);
@@ -193,7 +206,7 @@
     }
 
     @Override
-    public void add(int index, Object e) {
+    public final void add(int index, Object e) {
         try {
             if(index < 0) {
                 throw invalidIndex(index);
@@ -229,40 +242,40 @@
     }
 
     @Override
-    public boolean offer(Object e) {
+    public final boolean offer(Object e) {
         return offerLast(e);
     }
 
     @Override
-    public boolean offerFirst(Object e) {
+    public final boolean offerFirst(Object e) {
         addFirst(e);
         return true;
     }
 
     @Override
-    public boolean offerLast(Object e) {
+    public final boolean offerLast(Object e) {
         addLast(e);
         return true;
     }
 
     @Override
-    public Object pop() {
+    public final Object pop() {
         return removeFirst();
     }
 
     @Override
-    public Object remove() {
+    public final Object remove() {
         return removeFirst();
     }
 
     @Override
-    public Object removeFirst() {
+    public final Object removeFirst() {
         checkNonEmpty();
         return invokeShift();
     }
 
     @Override
-    public Object removeLast() {
+    public final Object removeLast() {
         checkNonEmpty();
         return invokePop();
     }
@@ -274,7 +287,7 @@
     }
 
     @Override
-    public Object remove(int index) {
+    public final Object remove(int index) {
         if(index < 0) {
             throw invalidIndex(index);
         } else if (index == 0) {
@@ -320,7 +333,7 @@
     }
 
     @Override
-    protected void removeRange(int fromIndex, int toIndex) {
+    protected final void removeRange(int fromIndex, int toIndex) {
         invokeSpliceRemove(fromIndex, toIndex - fromIndex);
     }
 
@@ -338,54 +351,54 @@
     }
 
     @Override
-    public Object poll() {
+    public final Object poll() {
         return pollFirst();
     }
 
     @Override
-    public Object pollFirst() {
+    public final Object pollFirst() {
         return isEmpty() ? null : invokeShift();
     }
 
     @Override
-    public Object pollLast() {
+    public final Object pollLast() {
         return isEmpty() ? null : invokePop();
     }
 
     @Override
-    public Object peek() {
+    public final Object peek() {
         return peekFirst();
     }
 
     @Override
-    public Object peekFirst() {
+    public final Object peekFirst() {
         return isEmpty() ? null : get(0);
     }
 
     @Override
-    public Object peekLast() {
+    public final Object peekLast() {
         return isEmpty() ? null : get(size() - 1);
     }
 
     @Override
-    public Object element() {
+    public final Object element() {
         return getFirst();
     }
 
     @Override
-    public Object getFirst() {
+    public final Object getFirst() {
         checkNonEmpty();
         return get(0);
     }
 
     @Override
-    public Object getLast() {
+    public final Object getLast() {
         checkNonEmpty();
         return get(size() - 1);
     }
 
     @Override
-    public Iterator<Object> descendingIterator() {
+    public final Iterator<Object> descendingIterator() {
         final ListIterator<Object> it = listIterator(size());
         return new Iterator<Object>() {
             @Override
@@ -406,12 +419,12 @@
     }
 
     @Override
-    public boolean removeFirstOccurrence(Object o) {
+    public final boolean removeFirstOccurrence(Object o) {
         return removeOccurrence(o, iterator());
     }
 
     @Override
-    public boolean removeLastOccurrence(Object o) {
+    public final boolean removeLastOccurrence(Object o) {
         return removeOccurrence(o, descendingIterator());
     }
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/src/jdk/nashorn/internal/runtime/ScriptObjectListAdapter.java	Mon Sep 16 15:08:36 2013 +0530
@@ -0,0 +1,54 @@
+/*
+ * 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.  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.internal.runtime;
+
+/**
+ * A ListAdapter that can wrap a ScriptObject.
+ */
+public final class ScriptObjectListAdapter extends ListAdapter {
+    /**
+     * Creates a new list wrapper for the specified ScriptObject.
+     * @param obj script the object to wrap
+     */
+    public ScriptObjectListAdapter(final ScriptObject obj) {
+        super(obj);
+    }
+
+    @Override
+    public int size() {
+        return JSType.toInt32(((ScriptObject)obj).getLength());
+    }
+
+    @Override
+    protected Object getAt(int index) {
+        return ((ScriptObject)obj).get(index);
+    }
+
+    @Override
+    protected void setAt(int index, Object element) {
+        ((ScriptObject)obj).set(index, element, false);
+    }
+}

--- a/nashorn/src/jdk/nashorn/internal/runtime/arrays/ArrayData.java	Fri Sep 13 17:50:18 2013 +0530
+++ b/nashorn/src/jdk/nashorn/internal/runtime/arrays/ArrayData.java	Mon Sep 16 15:08:36 2013 +0530
@@ -26,10 +26,9 @@
 package jdk.nashorn.internal.runtime.arrays;
 
 import java.lang.invoke.MethodHandle;
-import java.lang.reflect.Array;
 import jdk.nashorn.internal.runtime.GlobalObject;
+import jdk.nashorn.internal.runtime.JSType;
 import jdk.nashorn.internal.runtime.PropertyDescriptor;
-import jdk.nashorn.internal.runtime.linker.Bootstrap;
 
 /**
  * ArrayData - abstraction for wrapping array elements
@@ -204,20 +203,7 @@
      * @return and array of the given type
      */
     public Object asArrayOfType(final Class<?> componentType) {
-        final Object[] src = asObjectArray();
-        final int l = src.length;
-        final Object dst = Array.newInstance(componentType, l);
-        final MethodHandle converter = Bootstrap.getLinkerServices().getTypeConverter(Object.class, componentType);
-        try {
-            for (int i = 0; i < src.length; i++) {
-                Array.set(dst, i, invoke(converter, src[i]));
-            }
-        } catch (final RuntimeException | Error e) {
-            throw e;
-        } catch (final Throwable t) {
-            throw new RuntimeException(t);
-        }
-        return dst;
+        return JSType.convertArray(asObjectArray(), componentType);
     }
 
     /**

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/test/script/basic/JDK-8024847.js	Mon Sep 16 15:08:36 2013 +0530
@@ -0,0 +1,102 @@
+/*
+ * 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-8024847: Java.to should accept mirror and external JSObjects as array-like objects as well
+ *
+ * @test
+ * @run
+ */
+
+var global = loadWithNewGlobal({ name: "test", script:"this" });
+var arr = new global.Array(2, 4, 6, 8);
+var jarr = Java.to(arr, "int[]");
+for (var i in jarr) {
+    print(jarr[i]);
+}
+
+arr = null;
+jarr = null;
+
+// external JSObjects
+var JSObject = Java.type("jdk.nashorn.api.scripting.JSObject");
+var arr = new JSObject() {
+    getMember: function(name) {
+        return name == "length"? 4 : undefined;
+    },
+
+    hasMember: function(name) {
+        return name == "length";
+    },
+
+    getSlot: function(idx) {
+        return idx*idx;
+    },
+
+    hasSlot: function(idx) {
+        return true;
+    }
+};
+
+var jarr = Java.to(arr, "int[]");
+for (var i in jarr) {
+    print(jarr[i]);
+}
+
+arr = null;
+jarr = null;
+
+// List conversion
+var arr = global.Array("hello", "world");
+var jlist = Java.to(arr, java.util.List);
+print(jlist instanceof java.util.List);
+print(jlist);
+
+arr = null;
+jlist = null;
+
+// external JSObject
+var __array__ =  [ "nashorn", "js" ];
+
+var obj = new JSObject() {
+    
+    hasMember: function(name) {
+        return name in __array__;
+    },
+
+    hasSlot: function(idx) {
+        return idx in __array__;
+    },
+
+    getMember: function(name) {
+        return __array__[name];
+    },
+
+    getSlot: function(idx) {
+        return __array__[idx];
+    }
+}
+
+var jlist = Java.to(obj, java.util.List);
+print(jlist instanceof java.util.List);
+print(jlist);

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/test/script/basic/JDK-8024847.js.EXPECTED	Mon Sep 16 15:08:36 2013 +0530
@@ -0,0 +1,12 @@
+2
+4
+6
+8
+0
+1
+4
+9
+true
+[hello, world]
+true
+[nashorn, js]