Fix sputnik regression introduced in r5943.

src/array.js

 // Copyright 2006-2008 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 150 matching lines @@
 
 function ConvertToString(x) {
   if (IS_STRING(x)) return x;
   if (IS_NUMBER(x)) return %_NumberToString(x);
   if (IS_BOOLEAN(x)) return x ? 'true' : 'false';
   return (IS_NULL_OR_UNDEFINED(x)) ? '' : %ToString(%DefaultString(x));
 }
 
 
 function ConvertToLocaleString(e) {
-  // e_obj's toLocaleString might be overwritten, check if it is a function.
-  // Call ConvertToString if toLocaleString is not a function.
-  // See issue 877615.
-  var e_obj = ToObject(e);
-  if (IS_FUNCTION(e_obj.toLocaleString))
-    return ToString(e_obj.toLocaleString());
-  else
-    return ConvertToString(e);
+  if (e == null) {
+    return '';
+  } else {
+    // e_obj's toLocaleString might be overwritten, check if it is a function.
+    // Call ToString if toLocaleString is not a function.
+    // See issue 877615.
+    var e_obj = ToObject(e);
+    if (IS_FUNCTION(e_obj.toLocaleString))
+      return ToString(e_obj.toLocaleString());
+    else
+      return ToString(e);
+  }
 }
 
 
 // This function implements the optimized splice implementation that can use
 // special array operations to handle sparse arrays in a sensible fashion.
 function SmartSlice(array, start_i, del_count, len, deleted_elements) {
   // Move deleted elements to a new array (the return value from splice).
   // Intervals array can contain keys and intervals.  See comment in Concat.
   var intervals = %GetArrayKeys(array, start_i + del_count);
   var length = intervals.length;
@@ skipping 979 matching lines @@
     "lastIndexOf", getFunction("lastIndexOf", ArrayLastIndexOf, 1),
     "reduce", getFunction("reduce", ArrayReduce, 1),
     "reduceRight", getFunction("reduceRight", ArrayReduceRight, 1)
   ));
 
   %FinishArrayPrototypeSetup($Array.prototype);
 }
 
 
 SetupArray();