t.Fatal(err)
	}
	defer f.Close()

	err = checkFileIsNotPartOfNetpoll(f)
	if err != nil {
		t.Fatal(err)
	}
}

func TestSerialFdsAreInitialised(t *testing.T) {
	for _, name := range []string{"COM1", "COM2", "COM3", "COM4"} {
		t.Run(name, func(t *testing.T) {
			h, err := syscall.CreateFile(syscall.StringToUTF16Ptr(name),
				syscall.GENERIC_READ|syscall.GENERIC_WRITE,
				0,
				nil,
				syscall.OPEN_EXISTING,

		path string
		want string
	}{
		{`C:\foo`, `C:\foo`},
		{`\\host\share\foo`, `\\host\share\foo`},
		{`\\host`, `\\host`},
		{`\\.\NUL`, `\\.\NUL`},
		{`NUL`, `\\.\NUL`},
		{`COM1`, `\\.\COM1`},
		{`a/NUL`, `\\.\NUL`},
	} {
		got, err := filepath.Abs(test.path)
		if err != nil || got != test.want {
			t.Errorf("Abs(%q) = %q, %v; want %q, nil", test.path, got, err, test.want)
		}
	}

// It must not end with a dot (U+002E), nor contain two dots in a row.
//
// The element prefix up to the first dot must not be a reserved file name
// on Windows, regardless of case (CON, com1, NuL, and so on). The element
// must not have a suffix of a tilde followed by one or more ASCII digits
// (to exclude paths elements that look like Windows short-names).
//

	{"a/nul:", false},
	{"a/nul : a", false},
	{"com0", true},
	{"com1", false},
	{"com2", false},
	{"com3", false},
	{"com4", false},
	{"com5", false},
	{"com6", false},
	{"com7", false},
	{"com8", false},
	{"com9", false},
	{"com¹", false},
	{"com²", false},
	{"com³", false},
	{"com¹ : a", false},
	{"cOm1", false},
	{"lpt1", false},
	{"LPT1", false},
	{"lpt³", false},