I wondered why we needed to pass sti as well as ours and theirs but it 
is because when we're using AHEAD_BEHIND_QUICK our and theirs are always 
zero and so we need to check sti to see if the branch is up to date. 
Perhaps we could make this a boolean called 'up_to_date' ?

Yes, this is the reason. And I tried a lot of things to get around it. But
yes, let's pass this boolean instead.

This could be 'bool' not 'int'

Everything else looks fine - it is a faithful conversion from the 
original and it makes sense to check if the upstream is gone in the caller.

Done, will be in the next patch.

I didn't update the signature of 'format_tracking_info' to have a bool
there too, because it makes the surface area bigger of also updating the .h
file there.


Harald