Mirroring repository state, with branches and submodules.

[Toby White <toby.o.h.white@googlemail.com>]

I have a short script which does the following for a remote git  
rpository:

Clones it (checking out a working tree)
Makes tracking local branches for all remote branches
Init/updates all submodules.

This gives me an up-to-date mirror of a remote repository. I treat  
this as essentially read-only.

What I now want to do is have some command which will update this  
local mirror to reflect exactly the state of the remote mirror;
even when the remote mirror may have rebased history.

So far, I'm doing the following:

git fetch
for BRANCH in $(git branch -r | cut -d / -f 2); do
   git checkout $BRANCH
   git reset --hard origin/$BRANCH
done
git submodule update --init

but I'm not sure if that's actually the right way to do it, or if I'm  
missing any corner cases. Am I safe to use it?

Thanks,
Toby