> I'd rather remove the complete section (However, that means that you have 
> to introduce a function to do that in config.c)

No problem.

> Also, the second part of your patch would be clearer (methinks) if you 
> replaced the call to get_sha1() with dwim_ref(). You'd get the real 
> refname for free...

Not only that, my previous version did not work if somebody specified
remotes/remote/upstreambranch instead of remote/upstreambranch.

Updated version attached.

Paolo