From faa0ba932ed9d62a5476a6e62d87069e5ef884b4 Mon Sep 17 00:00:00 2001
From: Andrew Dupont <prototype@andrewdupont.net>
Date: Thu, 4 Apr 2013 18:58:53 -0500
Subject: [PATCH] Fix an issue with a capability check causing an error in IE
 10.

---
 src/prototype/dom/dom.js | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/prototype/dom/dom.js b/src/prototype/dom/dom.js
index 7b72941c5..f97ac77ec 100644
--- a/src/prototype/dom/dom.js
+++ b/src/prototype/dom/dom.js
@@ -2336,9 +2336,12 @@
   }
   
   var PROBLEMATIC_ATTRIBUTE_READING = (function() {
-    DIV.setAttribute('onclick', Prototype.emptyFunction);
+    // This test used to set 'onclick' to `Prototype.emptyFunction`, but that
+    // caused an (uncatchable) error in IE 10. For some reason, switching to
+    // an empty array prevents this issue.
+    DIV.setAttribute('onclick', []);
     var value = DIV.getAttribute('onclick');
-    var isFunction = (typeof value === 'function');
+    var isFunction = Object.isArray(value);
     DIV.removeAttribute('onclick');
     return isFunction;
   })();