Wow, bizarre. You should add that SO link to the comment.

Thanks, added.

Unfortunately, this fix does not help me. isSameOrigin method returns false in ie.

Herokuapp.com have not same port with origins

console.log(url.hostname, o.hostname, url.port, o.port, url.protocol, o.protocol);

i got:

site.com site.com 80  http: http:

So the ports sometimes don't match, I shall make more tests against the default 80 (for http) and 443 (for https) ports, and some randomly specified ports in IE.

@jackkum

However, we've been using 80 port on production for quite a while and no related bug report from client (using IE9+) yet. Could you provide your browser version and OS version?

@peter-fu

One my friend using phone with OS winphone 8.1 and browser IE could not log in.
I'm try log in with notebook with OS Win7 IE (unfortunately don't remember version 8 or 9)

I don't have a windows now, today evening I'll do a little investigation 😄

Interesting http://stackoverflow.com/questions/13167302/did-ie10-change-the-definition-of-window-location-port
looks like it's a bug in IE

@peter-fu
Windows 7, IE11