Version 1.1.0-dev.5.1

dart/sdk/lib/js/dart2js/js_dart2js.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Support for interoperating with JavaScript.
  * 
  * This library provides access to JavaScript objects from Dart, allowing
  * Dart code to get and set properties, and call methods of JavaScript objects
  * and invoke JavaScript functions. The library takes care of converting
@@ skipping 526 matching lines @@
     return _getDartProxy(o, _DART_OBJECT_PROPERTY_NAME,
         (o) => new JsArray._fromJs(o));
   } else {
     return _getDartProxy(o, _DART_OBJECT_PROPERTY_NAME,
         (o) => new JsObject._fromJs(o));
   }
 }
 
 Object _getDartProxy(o, String propertyName, createProxy(o)) {
   var dartProxy = JS('', '#[#]', o, propertyName);
-  if (dartProxy == null) {
+  // Temporary fix for dartbug.com/15193
+  // In some cases it's possible to see a JavaScript object that
+  // came from a different context and was previously proxied to
+  // Dart in that context. The JS object will have a cached proxy
+  // but it won't be a valid Dart object in this context.
+  // For now we throw away the cached proxy, but we should be able
+  // to cache proxies from multiple JS contexts and Dart isolates.
+  if (dartProxy == null || !_isLocalObject(o)) {
     dartProxy = createProxy(o);
     _defineProperty(o, propertyName, dartProxy);
   }
   return dartProxy;
 }