ajaxSettings.xhr breaks if IE activex disabled

[Irfan]

Ajax does not work on IE7 ActiveX are disabled.

Following is the XHR instantiation code in JQuery.

var xhr = window.ActiveXObject ? new ActiveXObject("Microsoft.XMLHTTP") : new XMLHttpRequest();

The check window.ActiveXObject returns non-null and non-undefined on IE7 even if activeX are disabled. However, the instantiation (new ActiveXObject("Microsoft.XMLHTTP")) throws an error. The code does not even use IE7's native XMLHttpRequest as a fallback.

This should be changed to something like:

var xhr;

try {

xhr = new ActiveXObject("Microsoft.XMLHTTP"); IE with ActiveX enabled

} catch(ex) {

xhr = new XMLHttpRequest(); IE7+ with ActiveX disabled and Non-IE

}

Steps to reproduce:

1. Disable ActiveX on IE7

(To disable ActiveX go to Tools -> Internet Options -> Security -> Internet/Intranet -> Custom Level -> Run ActiveX controls and plugins -> Disable.)

2. Try sending an Ajax Request.

Observed: JS error

Expected: JQuery should use the native XMLHttpRequest.

Versions: 1.2 to 1.2.6

[flesler]

Ok, we'll look into it asap.

[matthewk]

What's happening with this?

[dmurrell]

We experienced this today. A user had installed the latest version of IE7 (7.0.573.13) and now experienced this issue. In reviewing the security settings ActiveX was enabled. Internet zone was set to Medium-High.

We assumed this was caused by some non-obvious change in the enforcement of ActiveX security.

The change suggested solved the issue and is consistent with the Ajax transport handling in the Prototype library.

[trixi]

Information wether ajax is supported by the client should be avialable via jQuery.support.ajax

[dmethvin]

See related tickets #2849, #5338, #5529, when fixing this.

[john]

Fixed.  http://github.com/jquery/jquery/commit/b2289f3ec174c5b22d130d8c36a5e07daa6d02df