Fix bug in JSON.parse for objects containing "__proto__" as key.

src/parser.cc

 // Copyright 2010 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 4040 matching lines @@
       }
       Handle<String> key = GetString();
       if (scanner_.Next() != Token::COLON) {
         return ReportUnexpectedToken();
       }
       Handle<Object> value = ParseJsonValue();
       if (value.is_null()) return Handle<Object>::null();
       uint32_t index;
       if (key->AsArrayIndex(&index)) {
         SetOwnElement(json_object, index, value);
+      } else if (key->Equals(Heap::Proto_symbol())) {
+        // We can't remove the __proto__ accessor since it's hardcoded
+        // in several places. Instead go along and add the value as
+        // the prototype of the created object if possible.
+        SetPrototype(json_object, value);
       } else {
         SetLocalPropertyIgnoreAttributes(json_object, key, value, NONE);
       }
     } while (scanner_.Next() == Token::COMMA);
     if (scanner_.current_token() != Token::RBRACE) {
       return ReportUnexpectedToken();
     }
   }
   return json_object;
 }
@@ skipping 1023 matching lines @@
                                    info->is_global(),
                                    info->StrictMode());
     }
   }
 
   info->SetFunction(result);
   return (result != NULL);
 }
 
 } }  // namespace v8::internal