Ajax() bug on IE7

[kinming]

We used an modified version of jquery.autocomplete. After upgrade jquery from 1.2.6 to 1.4.2, autocomplete didn't work any more. As I dug deep, I found that the latest jquery have used a different way to create the XMLHTTPREQUEST. And yes, I noticed that you deal with IE7 specially. But in our IE7 browsers, this does NOT work properly. Both CHS and EN versions are failed.

BTW, are you sure this is right ? 'window.location.protocol !== "file:" ' (jquery-1.4.2.js, line 4952, look at this operator: "!==" )

[kinming]

Origin line 4952 is:

window.XMLHttpRequest && (window.location.protocol != "file:"

!window.ActiveXObject)

When I changed it into to :

window.XMLHttpRequest && !window.ActiveXObject

The ajax() works again. Both in IE6/7/8&Firefox. It looks like XMLHTTPREQUEST in IE7 is buggy. Maybe we should try not to use it?

[dmethvin]

Dup of #6298.