From 3f648c4e3abe236b8ec6a19822313be794e5a9df Mon Sep 17 00:00:00 2001
From: jeresig <jeresig@gmail.com>
Date: Tue, 5 Jan 2010 11:35:11 -0500
Subject: [PATCH] Make sure that the ActiveX exception is caught if it's unable
 to be loaded. Fixes #2849.

---
 src/ajax.js | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/ajax.js b/src/ajax.js
index 182a88e5a7..b5adf2c7fd 100644
--- a/src/ajax.js
+++ b/src/ajax.js
@@ -179,9 +179,14 @@ jQuery.extend({
 		// so we use the ActiveXObject when it is available
 		// This function can be overriden by calling jQuery.ajaxSetup
 		xhr: function() {
-			return window.XMLHttpRequest && window.location.protocol !== "file:" || window.ActiveXObject ?
-				new window.XMLHttpRequest() :
-				new window.ActiveXObject("Microsoft.XMLHTTP");
+			if ( window.XMLHttpRequest && (window.location.protocol !== "file:" || !window.ActiveXObject) ) {
+				return new window.XMLHttpRequest();
+
+			} else {
+				try {
+					return new window.ActiveXObject("Microsoft.XMLHTTP");
+				} catch(e) {}
+			}
 		},
 		accepts: {
 			xml: "application/xml, text/xml",
@@ -326,6 +331,10 @@ jQuery.extend({
 		// Create the request object
 		var xhr = s.xhr();
 
+		if ( !xhr ) {
+			return;
+		}
+
 		// Open the socket
 		// Passing null username, generates a login popup on Opera (#2865)
 		if ( s.username ) {