Changing branches in supermodule does not affect submodule?

Hi!

If I have a repository with submodules that is in a clean state, and switch 
branches in the super repository, the submodules are left in the state they 
were in before I switched branches (with 1.6.4, at least). Is this the 
expected behaviour?

--->8--8<---
#!/bin/bash
# Create supermodule.
mkdir super-$$
cd super-$$
git init

# Create submodule with commit.
mkdir sub
cd sub
git init
echo C > c.txt
echo D > d.txt
git add c.txt d.txt
git commit -m Created.
cd ..

# Create commit and branch in supermodule.
echo A > a.txt
echo B > b.txt
git add a.txt b.txt sub
git commit -m Created.
git tag branchpoint
git checkout -b branch1

# Create branch1 in submodule and commit.
cd sub
git checkout -b branch1
echo E > c.txt
echo F > d.txt
git add c.txt d.txt
git commit -m Branched.
cd ..

# Commit to a branch in the supermodule.
git add sub
git commit -m Sub-update.

# Status should now be clean.
git status

# Create a new branch in supermodule, from the original commit.
git checkout -b branch2 branchpoint

# I now expect the submodule to be up-to-date and the state clean.
git status
--->8--8<---

-- 
\\// Peter - http://www.softwolves.pp.se/