From f099e670f54bf5a006541b06b62bbfc611829943 Mon Sep 17 00:00:00 2001
From: Thomas Fuchs <thomas@fesch.at>
Date: Sat, 19 May 2007 00:11:46 +0000
Subject: [PATCH] Element.setOpacity now calls removeAttribute on the filter
 style on IE if no more filters remain, which makes Cleartype work properly. 
 Closes #8376.

---
 CHANGELOG          | 2 ++
 src/dom.js         | 8 ++++++--
 test/unit/dom.html | 1 +
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 7dc1131..a869c4b 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Element.setOpacity now calls removeAttribute on the filter style on IE if no more filters remain, which makes Cleartype work properly.  Closes #8376.  [alexdemi, Thomas Fuchs]
+
 * Event.findElement now uses Element#up (and as a result can take a CSS selector instead of just a tag name).  [Tobie Langel]
 
 * Minor cleanup of the position methods  [sam]
diff --git a/src/dom.js b/src/dom.js
index 8ce66e4..b17999b 100644
--- a/src/dom.js
+++ b/src/dom.js
@@ -689,13 +689,17 @@ else if (Prototype.Browser.IE) {
   };
   
   Element.Methods.setOpacity = function(element, value) {
+    function stripAlpha(filter){
+      return filter.replace(/alpha\([^\)]*\)/gi,'');
+    }
     element = $(element);
     var filter = element.getStyle('filter'), style = element.style;
     if (value == 1 || value === '') {
-      style.filter = filter.replace(/alpha\([^\)]*\)/gi,'');
+      (filter = stripAlpha(filter)) ?
+        style.filter = filter : style.removeAttribute('filter');
       return element;
     } else if (value < 0.00001) value = 0;
-    style.filter = filter.replace(/alpha\([^\)]*\)/gi, '') +
+    style.filter = stripAlpha(filter) +
       'alpha(opacity=' + (value * 100) + ')';
     return element;   
   };
diff --git a/test/unit/dom.html b/test/unit/dom.html
index aa2e1e1..55e9425 100644
--- a/test/unit/dom.html
+++ b/test/unit/dom.html
@@ -894,6 +894,7 @@
       assert(
         $('style_test_3').setOpacity(0.9999999).getStyle('opacity') > 0.999
       );
+      
     }},
     
     testElementGetStyle: function() { with(this) {