Make Element.extend work on IE for Nodes with the same ID that where discarded.

CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Make Element.extend work on IE for Nodes with the same ID that where discarded.  [Mislav Marohnić, Thomas Fuchs]
+
 * Make Selector correctly extend the first element it returns on IE.  [Thomas Fuchs]
 
 * Prevent a crash in Safari when using $A() on NodeList objects that contain text nodes.  [Thomas Fuchs]

src/dom.js

@@ -63,7 +63,7 @@ Element.extend = function(element) {
       element[property] = cache.findOrStore(value);
   }
 
-  element._extended = true;
+  element._extended = Prototype.emptyFunction;
   return element;
 };
 

test/unit/dom.html

@@ -153,6 +153,8 @@
 
 <div id="element_extend_test"> </div>
 
+<div id="element_reextend_test"><div id="discard_1"></div></div>
+
 <div id="test_whitespace"> <span> </span>
 
 
@@ -607,6 +609,12 @@
       });
     }},
     
+    testElementExtendReextendsDiscardedNodes: function() {with(this) {
+      assertRespondsTo('show', $('discard_1'));
+      $('element_reextend_test').innerHTML += '<div id="discard_2"></div>';
+      assertRespondsTo('show', $('discard_1'));
+    }},
+    
     testElementCleanWhitespace: function() {with(this) {
       Element.cleanWhitespace("test_whitespace");
       assertEqual(3, $("test_whitespace").childNodes.length);