[BUG] Symbolic links break "git fast-export"?

Hi folks,

Is my understanding correct, that `git fast-export | git fast-import` should not modify the repository? If yes, then we might have a bug in `git fast-export` if symbolic directory links are removed and converted to a real directory.

Consider this test case:

    # Create test repo
    git init .
    mkdir foo
    echo "foo" >foo/baz
    git add .
    git commit -m "add foo dir"
    ln -s foo bar
    git add .
    git commit -m "add bar dir as link"
    rm bar
    mkdir bar
    echo "bar" >bar/baz
    git add .
    git commit -m "remove link and make bar dir real"

    printf "BEFORE: "
    git rev-parse HEAD

    # Fast export, import ... that should not change anything!
    git fast-export --no-data --all --signed-tags=warn-strip \
        --tag-of-filtered-object=rewrite | git fast-import --force --quiet

    printf "AFTER: "

I would assume that the BEFORE/AFTER hashes match. Unfortunately, with Git 2.22.0 they do no. The problem is this export output I think:

    remove link and make bar dir real
    from :2
    M 100644 5716ca5987cbf97d6bb54920bea6adde242d87e6 bar/baz
    D bar

The new file in the `bar` directory is added to the repo first and afterwards the path `bar` is deleted. I think that deletes the entire directory `bar`?

If you confirm that this is a bug, then I will try to provide a fix.

Thanks, Lars