Steve, your PR checks `filename[n] == L':'`. I think it should check for a drive name, i.e. `n == 1 && filename[1] == L':'`. For example, the VirtualBox shared-folder filesystem allows creating and accessing filenames that contain and end with colons (e.g. "spam:" or even "./X:"), and such names can be queried with FindFirstFileW(). As long as a filename can be queried, I think it should be supported by attributes_from_dir().