Files added with intent to add disappear from file status view

Steps to reproduce

1. Create a new Git repository and open it in Sourcetree.
2. Create a new file in the repository.
3. Confirm the file is showing in Sourcetree by clicking on File Status and pressing F5 to refresh.
4. Run git add -N <filename> in the repository.
5. Refresh the File Status view in Sourcetree by pressing F5.

Expected results

The file is shown under Staged files with no content, and under Unstaged files as modified with all its content added.

Actual results

The file doesn't show up at all, the File Status view is empty.