Move-delete merge conflict is not displayed using git ls-files --unmerged

Lets consider repository state created with the following script (git
version 1.6.0.4).

mkdir test-move-delete
cd test-move-delete
git init
echo test1 >file.txt
echo test2 >>file.txt
echo test3 >>file.txt
echo test4 >>file.txt
git add file.txt
git commit -m "start"
git checkout -b moved master
git mv file.txt copy.txt
git commit -m "moved"
git checkout -b deleted master
git rm file.txt
git commit -m "deleted"
git merge moved

The last merge command fails with move-delete conflict.

CONFLICT (rename/delete): Renamed file.txt->copy.txt in moved and
deleted in HEAD
Automatic merge failed; fix conflicts and then commit the result.

However git ls-files --unmerged does not list any conflict in that
case and it is possible to execute git commit command right away
without doing anything with the repository.

I think that if git merge reports the conflicts, such conflicts should
be discoverable using git ls-files and prevent commit with resolving
the conflict like it is done with modify-delete conflicts.

Regards,
Constantine