Make toLocaleString on arrays always call toLocaleString on its elements.

src/js/array.js

Index: src/js/array.js
diff --git a/src/js/array.js b/src/js/array.js
index c29b8f7256ad1d2c568f5a5103d4c666f4aaf485..c28f96e8d94eaf3b0553a3abbb2d513804c63808 100644
--- a/src/js/array.js
+++ b/src/js/array.js
@@ -50,9 +50,9 @@ function KeySortCompare(a, b) {
 
 function GetSortedArrayKeys(array, indices) {
   if (IS_NUMBER(indices)) {
-    var keys = new InternalArray();
     // It's an interval
     var limit = indices;
+    var keys = new InternalArray();
     for (var i = 0; i < limit; ++i) {
       var e = array[i];
       if (!IS_UNDEFINED(e) || i in array) {
@@ -65,26 +65,24 @@ function GetSortedArrayKeys(array, indices) {
 }
 
 
-function SparseJoinWithSeparatorJS(array, keys, length, convert, separator) {
+function SparseJoinWithSeparatorJS(array, keys, length, use_locale, separator) {
   var keys_length = keys.length;
   var elements = new InternalArray(keys_length * 2);
   for (var i = 0; i < keys_length; i++) {
     var key = keys[i];
-    var e = array[key];
     elements[i * 2] = key;
-    elements[i * 2 + 1] = IS_STRING(e) ? e : convert(e);
+    elements[i * 2 + 1] = ConvertToString(use_locale, array[key]);
   }
   return %SparseJoinWithSeparator(elements, length, separator);
 }
 
 
 // Optimized for sparse arrays if separator is ''.
-function SparseJoin(array, keys, convert) {
+function SparseJoin(array, keys, use_locale) {
   var keys_length = keys.length;
   var elements = new InternalArray(keys_length);
   for (var i = 0; i < keys_length; i++) {
-    var e = array[keys[i]];
-    elements[i] = IS_STRING(e) ? e : convert(e);
+    elements[i] = ConvertToString(use_locale, array[keys[i]]);
   }
   return %StringBuilderConcat(elements, keys_length, '');
 }
@@ -137,60 +135,38 @@ function StackHas(stack, v) {
 // join invocations.
 var visited_arrays = new Stack();
 
-function DoJoin(array, length, is_array, separator, convert) {
+function DoJoin(array, length, is_array, separator, use_locale) {
   if (UseSparseVariant(array, length, is_array, length)) {
     %NormalizeElements(array);
     var keys = GetSortedArrayKeys(array, %GetArrayKeys(array, length));
     if (separator === '') {
       if (keys.length === 0) return '';
-      return SparseJoin(array, keys, convert);
+      return SparseJoin(array, keys, use_locale);
     } else {
-      return SparseJoinWithSeparatorJS(array, keys, length, convert, separator);
+      return SparseJoinWithSeparatorJS(
+          array, keys, length, use_locale, separator);
     }
   }
 
   // Fast case for one-element arrays.
   if (length === 1) {
-    var e = array[0];
-    return IS_STRING(e) ? e : convert(e);
+    return ConvertToString(use_locale, array[0]);
   }
 
   // Construct an array for the elements.
   var elements = new InternalArray(length);
+  for (var i = 0; i < length; i++) {
+    elements[i] = ConvertToString(use_locale, array[i]);
+  }
 
-  // We pull the empty separator check outside the loop for speed!
   if (separator === '') {
-    for (var i = 0; i < length; i++) {
-      var e = array[i];
-      elements[i] = IS_STRING(e) ? e : convert(e);
-    }
     return %StringBuilderConcat(elements, length, '');
-  }
-  // Non-empty separator case.
-  // If the first element is a number then use the heuristic that the
-  // remaining elements are also likely to be numbers.
-  var e = array[0];
-  if (IS_NUMBER(e)) {
-    elements[0] = %_NumberToString(e);
-    for (var i = 1; i < length; i++) {
-      e = array[i];
-      if (IS_NUMBER(e)) {
-        elements[i] = %_NumberToString(e);
-      } else {
-        elements[i] = IS_STRING(e) ? e : convert(e);
-      }
-    }
   } else {
-    elements[0] = IS_STRING(e) ? e : convert(e);
-    for (var i = 1; i < length; i++) {
-      e = array[i];
-      elements[i] = IS_STRING(e) ? e : convert(e);
-    }
+    return %StringBuilderJoin(elements, length, separator);
   }
-  return %StringBuilderJoin(elements, length, separator);
 }
 
-function Join(array, length, separator, convert) {
+function Join(array, length, separator, use_locale) {
   if (length === 0) return '';
 
   var is_array = IS_ARRAY(array);
@@ -204,7 +180,7 @@ function Join(array, length, separator, convert) {
 
   // Attempt to convert the elements.
   try {
-    return DoJoin(array, length, is_array, separator, convert);
+    return DoJoin(array, length, is_array, separator, use_locale);
   } finally {
     // Make sure to remove the last element of the visited array no
     // matter what happens.
@@ -213,15 +189,9 @@ function Join(array, length, separator, convert) {
 }
 
 
-function ConvertToString(x) {
+function ConvertToString(use_locale, x) {
   if (IS_NULL_OR_UNDEFINED(x)) return '';
-  return TO_STRING(x);
-}
-
-
-function ConvertToLocaleString(e) {
-  if (IS_NULL_OR_UNDEFINED(e)) return '';
-  return TO_STRING(e.toLocaleString());
+  return TO_STRING(use_locale ? x.toLocaleString() : x);
 }
 
 
@@ -368,7 +338,7 @@ function ArrayToString() {
   if (IS_ARRAY(this)) {
     func = this.join;
     if (func === ArrayJoin) {
-      return Join(this, this.length, ',', ConvertToString);
+      return Join(this, this.length, ',', false);
     }
     array = this;
   } else {
@@ -383,9 +353,7 @@ function ArrayToString() {
 
 
 function InnerArrayToLocaleString(array, length) {
-  var len = TO_LENGTH(length);
-  if (len === 0) return "";
-  return Join(array, len, ',', ConvertToLocaleString);
+  return Join(array, TO_LENGTH(length), ',', true);
 }
 
 
@@ -410,7 +378,7 @@ function InnerArrayJoin(separator, array, length) {
     return TO_STRING(e);
   }
 
-  return Join(array, length, separator, ConvertToString);
+  return Join(array, length, separator, false);
 }