Proxies: Make 'with' work, plus minor other fixes

src/contexts.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 106 matching lines @@
     if (FLAG_trace_contexts) {
       PrintF(" - looking in context %p", reinterpret_cast<void*>(*context));
       if (context->IsNativeContext()) PrintF(" (native context)");
       PrintF("\n");
     }
 
     // 1. Check global objects, subjects of with, and extension objects.
     if (context->IsNativeContext() ||
         context->IsWithContext() ||
         (context->IsFunctionContext() && context->has_extension())) {
-      Handle<JSObject> object(JSObject::cast(context->extension()), isolate);
+      Handle<JSReceiver> object(
+          JSReceiver::cast(context->extension()), isolate);
       // Context extension objects needs to behave as if they have no
       // prototype.  So even if we want to follow prototype chains, we need
       // to only do a local lookup for context extension objects.
       if ((flags & FOLLOW_PROTOTYPE_CHAIN) == 0 ||
           object->IsJSContextExtensionObject()) {
         *attributes = object->GetLocalPropertyAttribute(*name);
       } else {
         *attributes = object->GetPropertyAttribute(*name);
       }
+      if (isolate->has_pending_exception()) return Handle<Object>();
+
       if (*attributes != ABSENT) {
         if (FLAG_trace_contexts) {
           PrintF("=> found property in context object %p\n",
                  reinterpret_cast<void*>(*object));
         }
         return object;
       }
     }
 
     // 2. Check the context proper if it has slots.
@@ skipping 206 matching lines @@
   // During bootstrapping we allow all objects to pass as global
   // objects. This is necessary to fix circular dependencies.
   Isolate* isolate = Isolate::Current();
   return isolate->heap()->gc_state() != Heap::NOT_IN_GC ||
       isolate->bootstrapper()->IsActive() ||
       object->IsGlobalObject();
 }
 #endif
 
 } }  // namespace v8::internal