Fix Array.prototype.sort for *_STRING_WRAPPER_ELEMENTS

src/runtime/runtime-array.cc

 // Copyright 2014 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/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/conversions-inl.h"
 #include "src/elements.h"
 #include "src/factory.h"
@@ skipping 181 matching lines @@
 // might have elements.  Can either return an array of keys (positive integers
 // or undefined) or a number representing the positive length of an interval
 // starting at index 0.
 // Intervals can span over some keys that are not in the object.
 RUNTIME_FUNCTION(Runtime_GetArrayKeys) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 2);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, array, 0);
   CONVERT_NUMBER_CHECKED(uint32_t, length, Uint32, args[1]);
 
+  if (array->HasFastStringWrapperElements()) {
+    int string_length =
+        String::cast(Handle<JSValue>::cast(array)->value())->length();
+    int backing_store_length = array->elements()->length();
+    return *isolate->factory()->NewNumberFromUint(
+        Min(length,
+            static_cast<uint32_t>(Max(string_length, backing_store_length))));
+  }
+
   if (!array->elements()->IsDictionary()) {
     RUNTIME_ASSERT(array->HasFastSmiOrObjectElements() ||
                    array->HasFastDoubleElements());
     uint32_t actual_length = static_cast<uint32_t>(array->elements()->length());
     return *isolate->factory()->NewNumberFromUint(Min(actual_length, length));
   }
 
   KeyAccumulator accumulator(isolate, OWN_ONLY, ALL_PROPERTIES);
-  // No need to separate protoype levels since we only get numbers/element keys
+  // No need to separate prototype levels since we only get element keys.
   for (PrototypeIterator iter(isolate, array,
                               PrototypeIterator::START_AT_RECEIVER);
        !iter.IsAtEnd(); iter.Advance()) {
     if (PrototypeIterator::GetCurrent(iter)->IsJSProxy() ||
         PrototypeIterator::GetCurrent<JSObject>(iter)
             ->HasIndexedInterceptor()) {
       // Bail out if we find a proxy or interceptor, likely not worth
       // collecting keys in that case.
       return *isolate->factory()->NewNumberFromUint(length);
     }
@@ skipping 274 matching lines @@
   CONVERT_ARG_HANDLE_CHECKED(Object, original_array, 0);
   Handle<Object> constructor;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
       isolate, constructor,
       Object::ArraySpeciesConstructor(isolate, original_array));
   return *constructor;
 }
 
 }  // namespace internal
 }  // namespace v8