br.ReadRune()
	br.Discard(1)
	if err := br.UnreadRune(); err == nil {
		t.Error("UnreadRune didn't fail after Discard")
	}
}

func TestNoUnreadByteAfterDiscard(t *testing.T) {
	br := NewReader(strings.NewReader("example"))
	br.ReadByte()
	br.Discard(1)
	if err := br.UnreadByte(); err == nil {
		t.Error("UnreadByte didn't fail after Discard")
	}
}

	if err != nil {
		t.Fatal(err)
	}
	for i, f := range z.File {
		r, err := f.Open()
		if err != nil {
			continue
		}
		if f.UncompressedSize64 < 1e6 {
			n, err := io.Copy(io.Discard, r)
			if i == 3 && err != io.ErrUnexpectedEOF {
				t.Errorf("File[3] error = %v; want io.ErrUnexpectedEOF", err)
			}
			if err == nil && uint64(n) != f.UncompressedSize64 {

}

// addToFlag appends args to flag.
func (p *Package) addToFlag(flag string, args []string) {
	if flag == "CFLAGS" {
		// We'll also need these when preprocessing for dwarf information.
		// However, discard any -g options: we need to be able
		// to parse the debug info, so stick to what we expect.
		for _, arg := range args {
			if !strings.HasPrefix(arg, "-g") {
				p.GccOptions = append(p.GccOptions, arg)
			}
		}