git add -p and unresolved conflicts

I'm running git version 1.7.9.msysgit.0.390.g01fca.dirty, and I've
noticed a puzzling behavior with "git add -p" on a conflicted file: it
seems to simply spew the diff and exit the process.

Is this the expected behavior? It doesn't seem very useful to me...

Here's how to reproduce the behavior:

git init /tmp/git-add--p-conflict
cd /tmp/git-add--p-conflict/
echo "foo" > bar.txt
git add bar.txt
git commit -m.
echo "bar" >> bar.txt
git stash save
echo "baz" >> bar.txt
git commit -am.
git stash pop
git add -p bar.txt