Make delete API consistent for String objects

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 3463 matching lines @@
   // Check if the given key is an array index.
   uint32_t index;
   if (key->ToArrayIndex(&index)) {
     // In Firefox/SpiderMonkey, Safari and Opera you can access the
     // characters of a string using [] notation.  In the case of a
     // String object we just need to redirect the deletion to the
     // underlying string if the index is in range.  Since the
     // underlying string does nothing with the deletion, we can ignore
     // such deletions.
     if (receiver->IsStringObjectWithCharacterAt(index)) {
-      return isolate->factory()->true_value();
+      return isolate->factory()->false_value();
     }
 
     return i::JSReceiver::DeleteElement(receiver, index, language_mode);
   }
 
   i::Handle<i::Name> name;
   if (key->IsName()) {
     name = i::Handle<i::Name>::cast(key);
   } else {
     // Call-back into JavaScript to convert the key to a string.
@@ skipping 4584 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal