Merge revision 6500-6600 from bleeding_edge to the isolates branch.

src/array.js

 // Copyright 2010 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 153 matching lines @@
     var length2 = (length << 1) - 1;
     var j = length2;
     var i = length;
     elements[--j] = elements[--i];
     while (i > 0) {
       elements[--j] = separator;
       elements[--j] = elements[--i];
     }
     return %StringBuilderConcat(elements, length2, '');    
   } finally {
-    // Make sure to pop the visited array no matter what happens.
-    if (is_array) visited_arrays.pop();
+    // Make sure to remove the last element of the visited array no
+    // matter what happens.
+    if (is_array) visited_arrays.length = visited_arrays.length - 1;
   }
 }
 
 
 function ConvertToString(x) {
   // Assumes x is a non-string. 
   if (IS_NUMBER(x)) return %_NumberToString(x);
   if (IS_BOOLEAN(x)) return x ? 'true' : 'false';
   return (IS_NULL_OR_UNDEFINED(x)) ? '' : %ToString(%DefaultString(x));
 }
@@ skipping 410 matching lines @@
   var start_i = TO_INTEGER(start);
 
   if (start_i < 0) {
     start_i += len;
     if (start_i < 0) start_i = 0;
   } else {
     if (start_i > len) start_i = len;
   }
 
   // SpiderMonkey, TraceMonkey and JSC treat the case where no delete count is
-  // given differently from when an undefined delete count is given.
+  // given as a request to delete all the elements from the start.
+  // And it differs from the case of undefined delete count.
   // This does not follow ECMA-262, but we do the same for
   // compatibility.
   var del_count = 0;
-  if (num_arguments > 1) {
+  if (num_arguments == 1) {
+    del_count = len - start_i;
+  } else {
     del_count = TO_INTEGER(delete_count);
     if (del_count < 0) del_count = 0;
     if (del_count > len - start_i) del_count = len - start_i;
-  } else {
-    del_count = len - start_i;
   }
 
   var deleted_elements = [];
   deleted_elements.length = del_count;
 
   // Number of elements to add.
   var num_additional_args = 0;
   if (num_arguments > 2) {
     num_additional_args = num_arguments - 2;
   }
@@ skipping 601 matching lines @@
     "lastIndexOf", getFunction("lastIndexOf", ArrayLastIndexOf, 1),
     "reduce", getFunction("reduce", ArrayReduce, 1),
     "reduceRight", getFunction("reduceRight", ArrayReduceRight, 1)
   ));
 
   %FinishArrayPrototypeSetup($Array.prototype);
 }
 
 
 SetupArray();