Fix bogus assertion.

src/objects.cc

 // Copyright 2013 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 13071 matching lines @@
       break;
     }
     case FAST_DOUBLE_ELEMENTS:
       if (IsJSArray()) {
         *capacity = backing_store_base->length();
         *used = Smi::cast(JSArray::cast(this)->length())->value();
         break;
       }
       // Fall through if packing is not guaranteed.
     case FAST_HOLEY_DOUBLE_ELEMENTS: {
-      FixedDoubleArray* elms = FixedDoubleArray::cast(elements());
-      *capacity = elms->length();
+      *capacity = elements()->length();
+      if (*capacity == 0) break;
+      FixedDoubleArray * elms = FixedDoubleArray::cast(elements());
       for (int i = 0; i < *capacity; i++) {
         if (!elms->is_the_hole(i)) ++(*used);
       }
       break;
     }
 
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size)                      \
     case EXTERNAL_##TYPE##_ELEMENTS:                                         \
     case TYPE##_ELEMENTS:                                                    \
 
@@ skipping 3387 matching lines @@
 #define ERROR_MESSAGES_TEXTS(C, T) T,
   static const char* error_messages_[] = {
       ERROR_MESSAGES_LIST(ERROR_MESSAGES_TEXTS)
   };
 #undef ERROR_MESSAGES_TEXTS
   return error_messages_[reason];
 }
 
 
 } }  // namespace v8::internal