* Fix a bug in the IE-specific Element#descendantOf logic. [Nicholas, Andrew Dupont]

CHANGELOG

@@ -1,3 +1,5 @@
+* Fix a bug in the IE-specific Element#descendantOf logic. [Nicholas, Andrew Dupont]
+
 * Make Ajax.Updater clone its options hash before modifying it. Prevents memory leaks in Ajax.PeriodicalUpdater. Closes #10049 [Mislav Marohnić, Tobie Langel].
 
 * Remove useless variable in Selector.handlers.child. Closes #10006 [kuriyama]

src/dom.js

@@ -359,6 +359,7 @@ Element.Methods = {
   
   descendantOf: function(element, ancestor) {
     element = $(element), ancestor = $(ancestor);
+    var originalAncestor = ancestor;
 
     if (element.compareDocumentPosition)
       return (element.compareDocumentPosition(ancestor) & 8) === 8;
@@ -374,7 +375,7 @@ Element.Methods = {
     }
     
     while (element = element.parentNode)
-      if (element == ancestor) return true;
+      if (element == originalAncestor) return true;
     return false;
   },
   

test/unit/dom.html

@@ -1031,6 +1031,8 @@
       assert(!$('sibling').descendantOf('child'), 'sibling < child');
       assert(!$('great-grand-child').descendantOf('not-in-the-family'), 'great-grand-child < not-in-the-family');
       assert(!$('child').descendantOf('not-in-the-family'), 'child < not-in-the-family');
+      
+      assert(!$(document.body).descendantOf('great-grand-child'));
     }},  
     
     testChildOf: function() {with(this) {