diff --git a/mozilla/js/rhino/src/org/mozilla/javascript/NativeObject.java b/mozilla/js/rhino/src/org/mozilla/javascript/NativeObject.java
index a46af60df57..325395f1079 100644
--- a/mozilla/js/rhino/src/org/mozilla/javascript/NativeObject.java
+++ b/mozilla/js/rhino/src/org/mozilla/javascript/NativeObject.java
@@ -93,6 +93,14 @@ public class NativeObject extends IdScriptableObject
                 "defineProperties", 2);
         addIdFunctionProperty(ctor, OBJECT_TAG, ConstructorId_create,
                 "create", 2);
+        addIdFunctionProperty(ctor, OBJECT_TAG, ConstructorId_isSealed,
+                "isSealed", 1);
+        addIdFunctionProperty(ctor, OBJECT_TAG, ConstructorId_isFrozen,
+                "isFrozen", 1);
+        addIdFunctionProperty(ctor, OBJECT_TAG, ConstructorId_seal,
+                "seal", 1);
+        addIdFunctionProperty(ctor, OBJECT_TAG, ConstructorId_freeze,
+                "freeze", 1);
         super.fillConstructorProperties(ctor);
     }
 
@@ -364,10 +372,73 @@ public class NativeObject extends IdScriptableObject
                 if (args.length > 1 && args[1] != Undefined.instance) {
                   Scriptable props = Context.toObject(args[1], getParentScope());
                   newObject.defineOwnProperties(cx, ensureScriptableObject(props));
-    }
+                }
 
                 return newObject;
-    }
+              }
+
+          case ConstructorId_isSealed:
+              {
+                Object arg = args.length < 1 ? Undefined.instance : args[0];
+                ScriptableObject obj = ensureScriptableObject(arg);
+
+                for (Object name: obj.getAllIds()) {
+                  Object configurable = obj.getOwnPropertyDescriptor(cx, name).get("configurable");
+                  if (Boolean.TRUE.equals(configurable)) 
+                    return false;
+                }
+
+                return !obj.isExtensible();
+              }
+          case ConstructorId_isFrozen:
+              {
+                Object arg = args.length < 1 ? Undefined.instance : args[0];
+                ScriptableObject obj = ensureScriptableObject(arg);
+
+                for (Object name: obj.getAllIds()) {
+                  ScriptableObject desc = obj.getOwnPropertyDescriptor(cx, name);
+                  if (Boolean.TRUE.equals(desc.get("configurable"))) 
+                    return false;
+                  if (isDataDescriptor(desc) && Boolean.TRUE.equals(desc.get("writable")))
+                    return false;
+                }
+
+                return !obj.isExtensible();
+              }
+          case ConstructorId_seal:
+              {
+                Object arg = args.length < 1 ? Undefined.instance : args[0];
+                ScriptableObject obj = ensureScriptableObject(arg);
+
+                for (Object name: obj.getAllIds()) {
+                  ScriptableObject desc = obj.getOwnPropertyDescriptor(cx, name);
+                  if (Boolean.TRUE.equals(desc.get("configurable"))) {
+                    desc.put("configurable", desc, false);
+                    obj.defineOwnProperty(cx, name, desc); 
+                  }
+                }
+                obj.preventExtensions();
+
+                return obj;
+              }
+          case ConstructorId_freeze:
+              {
+                Object arg = args.length < 1 ? Undefined.instance : args[0];
+                ScriptableObject obj = ensureScriptableObject(arg);
+
+                for (Object name: obj.getAllIds()) {
+                  ScriptableObject desc = obj.getOwnPropertyDescriptor(cx, name);
+                  if (isDataDescriptor(desc) && Boolean.TRUE.equals(desc.get("writable")))
+                    desc.put("writable", desc, false);
+                  if (Boolean.TRUE.equals(desc.get("configurable")))
+                    desc.put("configurable", desc, false);
+                  obj.defineOwnProperty(cx, name, desc);
+                }
+                obj.preventExtensions();
+
+                return obj;
+              }
+
 
           default:
             throw new IllegalArgumentException(String.valueOf(id));
@@ -425,6 +496,10 @@ public class NativeObject extends IdScriptableObject
         ConstructorId_preventExtensions = -7,
         ConstructorId_defineProperties= -8,
         ConstructorId_create = -9,
+        ConstructorId_isSealed = -10,
+        ConstructorId_isFrozen = -11,
+        ConstructorId_seal = -12,
+        ConstructorId_freeze = -13,
 
         Id_constructor           = 1,
         Id_toString              = 2,
diff --git a/mozilla/js/rhino/src/org/mozilla/javascript/ScriptableObject.java b/mozilla/js/rhino/src/org/mozilla/javascript/ScriptableObject.java
index 15fe3982d38..31ab96cac67 100644
--- a/mozilla/js/rhino/src/org/mozilla/javascript/ScriptableObject.java
+++ b/mozilla/js/rhino/src/org/mozilla/javascript/ScriptableObject.java
@@ -1653,15 +1653,15 @@ public abstract class ScriptableObject implements Scriptable, Serializable,
       return attributes;
     }
 
-    private boolean isDataDescriptor(ScriptableObject desc) {
+    protected boolean isDataDescriptor(ScriptableObject desc) {
       return hasProperty(desc, "value") || hasProperty(desc, "writable");
     }
-    
-    private boolean isAccessorDescriptor(ScriptableObject desc) {
+
+    protected boolean isAccessorDescriptor(ScriptableObject desc) {
       return hasProperty(desc, "get") || hasProperty(desc, "set");
     }
-    
-    private boolean isGenericDescriptor(ScriptableObject desc) {
+
+    protected boolean isGenericDescriptor(ScriptableObject desc) {
       return !isDataDescriptor(desc) && !isAccessorDescriptor(desc);
     }
 
diff --git a/mozilla/js/rhino/testsrc/doctests/object.freeze.doctest b/mozilla/js/rhino/testsrc/doctests/object.freeze.doctest
new file mode 100644
index 00000000000..db3f023c79c
--- /dev/null
+++ b/mozilla/js/rhino/testsrc/doctests/object.freeze.doctest
@@ -0,0 +1,27 @@
+js> load('testsrc/doctests/util.js');
+
+js> Object.freeze;
+function freeze() { [native code for Object.freeze, arity=1] }
+
+js> [undefined, null, true, 1, 'hello'].forEach(function(value) { 
+  >   expectTypeError(function() { Object.freeze(value) }) 
+  > })
+js> expectTypeError(function() { Object.freeze() })
+
+js> var x = {}
+js> var y = Object.freeze(x)
+js> x === y
+true
+
+js> var obj = Object.defineProperty({}, 'a', {configurable:true, writable:true})
+js> var _ = Object.freeze(obj)
+js> var a = Object.getOwnPropertyDescriptor(obj, 'a');
+js> a.configurable
+false
+js> a.writable
+false
+js> Object.isExtensible(obj)
+false
+
+js> Object.isFrozen(obj)
+true
diff --git a/mozilla/js/rhino/testsrc/doctests/object.isfrozen.doctest b/mozilla/js/rhino/testsrc/doctests/object.isfrozen.doctest
new file mode 100644
index 00000000000..b2206f92df9
--- /dev/null
+++ b/mozilla/js/rhino/testsrc/doctests/object.isfrozen.doctest
@@ -0,0 +1,37 @@
+js> load('testsrc/doctests/util.js');
+
+js> Object.isFrozen
+function isFrozen() { [native code for Object.isFrozen, arity=1] }
+
+js> expectTypeError(function() { Object.isFrozen() });
+js> [undefined, null, true, 1, 'hello'].forEach(function(value) { 
+  >   expectTypeError(function() { Object.isFrozen(value) }) 
+  > })
+
+js> Object.isFrozen({})
+false
+
+js> var obj = Object.preventExtensions({});
+js> Object.isFrozen(obj);
+true
+
+js> var obj = Object.defineProperty({}, 'a', {configurable:true, writable:false})
+js> var _ = Object.preventExtensions(obj);
+js> Object.isFrozen(obj);
+false
+
+js> var obj = Object.defineProperty({}, 'a', {configurable:false, writable:true})
+js> var _ = Object.preventExtensions(obj);
+js> Object.isFrozen(obj);
+false
+
+js> var obj = Object.defineProperty({}, 'a', {configurable:false, writable:false})
+js> var _ = Object.preventExtensions(obj);
+js> Object.isFrozen(obj);
+true
+
+js> var obj = Object.defineProperty({}, 'a', {configurable:false, set: function(){} })
+js> var _ = Object.preventExtensions(obj);
+js> Object.isFrozen(obj);
+true
+
diff --git a/mozilla/js/rhino/testsrc/doctests/object.issealed.doctest b/mozilla/js/rhino/testsrc/doctests/object.issealed.doctest
new file mode 100644
index 00000000000..275b4acaf56
--- /dev/null
+++ b/mozilla/js/rhino/testsrc/doctests/object.issealed.doctest
@@ -0,0 +1,26 @@
+js> load('testsrc/doctests/util.js');
+
+js> Object.isSealed
+function isSealed() { [native code for Object.isSealed, arity=1] }
+
+js> expectTypeError(function() { Object.isSealed() });
+js> [undefined, null, true, 1, 'hello'].forEach(function(value) { 
+  >   expectTypeError(function() { Object.isSealed(value) }) 
+  > })
+
+js> Object.isSealed({})
+false
+
+js> var obj = Object.preventExtensions({});
+js> Object.isSealed(obj);
+true
+
+js> var obj = Object.defineProperty({}, 'a', {configurable:false});
+js> var _ = Object.preventExtensions(obj);
+js> Object.isSealed(obj);
+true
+
+js> var obj = Object.defineProperty({}, 'a', {configurable:true});
+js> var _ = Object.preventExtensions(obj);
+js> Object.isSealed(obj);
+false
diff --git a/mozilla/js/rhino/testsrc/doctests/object.seal.doctest b/mozilla/js/rhino/testsrc/doctests/object.seal.doctest
new file mode 100644
index 00000000000..2f50804dda4
--- /dev/null
+++ b/mozilla/js/rhino/testsrc/doctests/object.seal.doctest
@@ -0,0 +1,24 @@
+js> load('testsrc/doctests/util.js');
+
+js> Object.seal;
+function seal() { [native code for Object.seal, arity=1] }
+
+js> [undefined, null, true, 1, 'hello'].forEach(function(value) { 
+  >   expectTypeError(function() { Object.seal(value) }) 
+  > })
+js> expectTypeError(function() { Object.seal() })
+
+js> var x = {}
+js> var y = Object.seal(x)
+js> x === y
+true
+
+js> var obj = Object.defineProperty({}, 'a', {configurable:true})
+js> var _ = Object.seal(obj)
+js> Object.getOwnPropertyDescriptor(obj, 'a').configurable
+false
+js> Object.isExtensible(obj)
+false
+
+js> Object.isSealed(obj)
+true