From f3f3238c53a3cad8ebe5c4be191ac4c5d0990f06 Mon Sep 17 00:00:00 2001
From: Brandon Aaron <brandon.aaron@gmail.com>
Date: Mon, 28 Apr 2008 21:09:27 +0000
Subject: [PATCH] jQuery.event.fix performance boost. An example: click event
 was previously ~3ms and is now < 1ms. jQuery.event.trigger also got another
 small boost in performance.

---
 src/event.js | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/event.js b/src/event.js
index 2d9bdc27a..0cf6c58e5 100644
--- a/src/event.js
+++ b/src/event.js
@@ -184,8 +184,16 @@ jQuery.event = {
 				event = !data[0] || !data[0].preventDefault;
 			
 			// Pass along a fake event
-			if ( event )
-				data.unshift( { type: type, target: elem } );
+			if ( event ) {
+				data.unshift({ 
+					type: type, 
+					target: elem, 
+					preventDefault: function(){}, 
+					stopPropagation: function(){}, 
+					timeStamp: +new Date
+				});
+				data[0][expando] = true; // no need to fix fake event
+			}
 
 			// Enforce the right trigger type
 			data[0].type = type;
@@ -265,11 +273,6 @@ jQuery.event = {
 			}
 		}
 
-		// Clean up added properties in IE to prevent memory leak
-		if (jQuery.browser.msie)
-			event.target = event.preventDefault = event.stopPropagation =
-				event.handler = event.data = event[expando] = null;
-
 		return val;
 	},
 
@@ -278,9 +281,12 @@ jQuery.event = {
 			return event;
 		
 		// store a copy of the original event object 
-		// and clone to set read-only properties
+		// and "clone" to set read-only properties
 		var originalEvent = event;
-		event = jQuery.extend({}, originalEvent);
+		event = { originalEvent: originalEvent };
+		var props = "altKey attrChange attrName bubbles button cancelable charCode clientX clientY ctrlKey currentTarget data detail eventPhase fromElement handler keyCode metaKey newValue pageX pageY prevValue relatedNode relatedTarget screenX screenY shiftKey srcElement target timeStamp toElement type view wheelDelta which".split(" ");
+		for ( var i=props.length; i; i-- )
+			event[ props[i] ] = originalEvent[ props[i] ];
 		
 		// Mark it as fixed
 		event[expando] = true;
@@ -311,7 +317,7 @@ jQuery.event = {
 				
 		// check if target is a textnode (safari)
 		if ( event.target.nodeType == 3 )
-			event.target = originalEvent.target.parentNode;
+			event.target = event.target.parentNode;
 
 		// Add relatedTarget, if necessary
 		if ( !event.relatedTarget && event.fromElement )
-- 
2.39.5