I was able to narrow down this supposedly IE+GWT issue with AuthSub
JS. It's actually not related to GWT. In the JS API, when calling
google.load("gdata", "1.10", callback) with a callback, in IE, authsub
doesn't complete - it never consumes the token in the URL.
This happens only when a callback is passed to google.load. The
behavior is the following.
1. Page calls google.accounts.user.login(myScope);
2. Browser is redirected to the Google authorization page.
3. User clicks to authorize.
4. Browser is redirected back to original page, with the token
appended to the URL.
5. In IE nothing happens. In FF the page will store the token in a
cookie and refresh to remove the token from the URL.
Also, curiously, at step 5, if we repeat steps 1 and 2, but at step 3
instead click the browser's back button, upon returning to the page,
the token is successfully consumed. Sounds like since the back button
will cause the page to be loaded from cache, google.load is available
immediately and AuthSub succeeds, which suggests that the fact that
google.load is asynchronous (when a callback is specified) and has a
slight delay, interferes with the AuthSub process.
I don't mind adding this to the issue tracker but i'm not sure where
the best place is to do that.