}
	// Test error after ReadSlice.
	_, _, err = r.ReadRune() // reset state
	if err != nil {
		t.Error("unexpected error on ReadRune (4):", err)
	}
	_, err = r.ReadSlice(0)
	if err != io.EOF {
		t.Error("unexpected error on ReadSlice (4):", err)
	}
	if r.UnreadRune() == nil {
		t.Error("expected error after ReadSlice (4)")
	}
}

func TestUnreadRuneAtEOF(t *testing.T) {