Fix bug in context stores, where the store was ignored if there was a...

src/runtime.cc

 // Copyright 2006-2009 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 4414 matching lines @@
   if (!holder.is_null()) {
     // The property exists in the extension context.
     context_ext = Handle<JSObject>::cast(holder);
   } else {
     // The property was not found. It needs to be stored in the global context.
     ASSERT(attributes == ABSENT);
     attributes = NONE;
     context_ext = Handle<JSObject>(Top::context()->global());
   }
 
-  // Set the property, but ignore if read_only variable.
-  if ((attributes & READ_ONLY) == 0) {
+  // Set the property, but ignore if read_only variable on the context
+  // extension object itself.
+  if ((attributes & READ_ONLY) == 0 ||
+      (context_ext->GetLocalPropertyAttribute(*name) == ABSENT)) {
     Handle<Object> set = SetProperty(context_ext, name, value, attributes);
     if (set.is_null()) {
       // Failure::Exception is converted to a null handle in the
       // handle-based methods such as SetProperty.  We therefore need
       // to convert null handles back to exceptions.
       ASSERT(Top::has_pending_exception());
       return Failure::Exception();
     }
   }
   return *value;
@@ skipping 2443 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
     Heap::CollectAllGarbage();
   }
 }
 
 
 } }  // namespace v8::internal