prototype: Fix Class#addMethods for "toString" and "valueOf" methods in Internet Explorer. Closes #9901.

CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Fix Class#addMethods for "toString" and "valueOf" methods in Internet Explorer.  Closes #9901.  [sam]
+
 * Exclude Opera from using the sourceIndex approach in Element#descendantOf. [Tobie Langel, Andrew Dupont]
 
 * Ensure Element#hasClassName always returns a boolean. Closes #10075. [ronnylovtangen, Tobie Langel]

src/base.js

@@ -34,10 +34,14 @@ var Class = {
 
 Class.Methods = {
   addMethods: function(source) {
-    var ancestor = this.superclass && this.superclass.prototype;
-
-    for (var property in source) {
-      var value = source[property];
+    var ancestor   = this.superclass && this.superclass.prototype;
+    var properties = Object.keys(source);
+    
+    if (!Object.keys({ toString: true }).length)
+      properties.push("toString", "valueOf");
+    
+    for (var i = 0, length = properties.length; i < length; i++) {
+      var property = properties[i], value = source[property];
       if (ancestor && Object.isFunction(value) &&
           value.argumentNames().first() == "$super") {
         var method = value, value = Object.extend((function(m) { 

test/unit/base.html

@@ -599,6 +599,21 @@
       assertEqual('#<Ox: cow>', cow.inspect());
       assertRespondsTo('reproduce', cow);
       assertRespondsTo('getValue', cow);
+   }},
+   
+   testClassWithToStringAndValueOfMethods: function() { with(this) {
+     var Foo = Class.create({
+       toString: function() {
+         return "toString";
+       },
+       
+       valueOf: function() {
+         return "valueOf";
+       }
+     });
+     
+     assertEqual("toString", new Foo().toString());
+     assertEqual("valueOf", new Foo().valueOf());
    }}
 
   }, 'testlog');