gistfile1.txt

mono 5.10.1

```
path = tmp/tmp2/aaa
parent ToString() = tmp/tmp2
parent Name = tmp2
parent FullName = /home/tmp/tmp2
```

gistfile2.txt

mono 6.0.0

```
path = tmp/tmp2/aaa
parent ToString() = /home/tmp/tmp2
parent Name = tmp2
parent FullName = /home/tmp/tmp2
```

main.cs

using System;
using System.IO;

class Program
{
    static void Main() {
        var path = "tmp/tmp2/aaa";
        System.Console.Write($"path = {path}\n");
        
        var parentPath = Directory.GetParent(path).ToString();
        System.Console.Write($"parent ToString() = {parentPath}\n");
        
        var n0 = Directory.GetParent(path).Name;
        System.Console.Write($"parent Name = {n0}\n");
        
        var n1 = Directory.GetParent(path).FullName;
        System.Console.Write($"parent FullName = {n1}\n");
    }
}