ValueSerializer: Check for zero length before casting to FixedDoubleArray.

src/value-serializer.cc

 // Copyright 2016 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/value-serializer.h"
 
 #include <type_traits>
 
 #include "src/base/logging.h"
 #include "src/conversions.h"
@@ skipping 536 matching lines @@
     // Fast paths. Note that FAST_ELEMENTS in particular can bail due to the
     // structure of the elements changing.
     switch (array->GetElementsKind()) {
       case FAST_SMI_ELEMENTS: {
         Handle<FixedArray> elements(FixedArray::cast(array->elements()),
                                     isolate_);
         for (; i < length; i++) WriteSmi(Smi::cast(elements->get(i)));
         break;
       }
       case FAST_DOUBLE_ELEMENTS: {
+        // Elements are empty_fixed_array, not a FixedDoubleArray, if the array
+        // is empty. No elements to encode in this case anyhow.
+        if (length == 0) break;
         Handle<FixedDoubleArray> elements(
             FixedDoubleArray::cast(array->elements()), isolate_);
         for (; i < length; i++) {
           WriteTag(SerializationTag::kDouble);
           WriteDouble(elements->get_scalar(i));
         }
         break;
       }
       case FAST_ELEMENTS: {
         Handle<Object> old_length(array->length(), isolate_);
@@ skipping 1367 matching lines @@
   if (stack.size() != 1) {
     isolate_->Throw(*isolate_->factory()->NewError(
         MessageTemplate::kDataCloneDeserializationError));
     return MaybeHandle<Object>();
   }
   return scope.CloseAndEscape(stack[0]);
 }
 
 }  // namespace internal
 }  // namespace v8