$ rm -rf d
$ mkdir d d/patches
$ cd d

$ echo f0 > f
$ quilt new foo
> Patch patches/foo is now on top

$ quilt add f
> File f added to patch patches/foo

$ echo f1 > f
$ quilt refresh
> Refreshed patch patches/foo

$ quilt delete foo
> Removing patch patches/foo
> No patches applied
> Removed patch patches/foo

$ cat patches/foo
> Index: d/f
> ===================================================================
> --- d.orig/f
> +++ d/f
> @@ -1 +1 @@
> -f0
> +f1


$ quilt new foo
> Patch patches/foo is now on top

$ quilt add f
> File f added to patch patches/foo

$ quilt diff -z
> Index: d/f
> ===================================================================
> --- d.orig/f
> +++ d/f
> @@ -1 +1 @@
> -f1
> +f0

$ cd ..
$ rm -rf d