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")
	}
}

				continue
			}
		}

		// If we were unable to read anything out of the archive don't
		// bother trying to roundtrip it.
		if len(files) == 0 {
			return
		}

		w := NewWriter(io.Discard)
		for _, f := range files {
			ww, err := w.CreateHeader(f.header)
			if err != nil {
				t.Fatalf("unable to write previously parsed header: %s", err)
			}
			if _, err := ww.Write(f.content); err != nil {

	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 {

pkg archive/zip, method (*Writer) SetOffset(int64)
pkg bufio, method (*Reader) Discard(int) (int, error)
pkg bufio, method (ReadWriter) Discard(int) (int, error)
pkg bytes, func LastIndexByte([]uint8, uint8) int
pkg bytes, method (*Buffer) Cap() int
pkg bytes, method (*Reader) Size() int64
pkg crypto, const SHA512_224 = 14
pkg crypto, const SHA512_224 Hash
pkg crypto, const SHA512_256 = 15
pkg crypto, const SHA512_256 Hash

computed modulo 2<sup><i>n</i></sup>, where <i>n</i> is the bit width of
the <a href="#Numeric_types">unsigned integer</a>'s type.
Loosely speaking, these unsigned integer operations
discard high bits upon overflow, and programs may rely on "wrap around".
</p>
<p>
For signed integers, the operations <code>+</code>,
<code>-</code>, <code>*</code>, <code>/</code>, and <code>&lt;&lt;</code> may legally

pkg syscall (netbsd-arm64-cgo), const TOSTOP = 4194304
pkg syscall (netbsd-arm64-cgo), const TOSTOP ideal-int
pkg syscall (netbsd-arm64-cgo), const VDISCARD = 15
pkg syscall (netbsd-arm64-cgo), const VDISCARD ideal-int
pkg syscall (netbsd-arm64-cgo), const VDSUSP = 11
pkg syscall (netbsd-arm64-cgo), const VDSUSP ideal-int
pkg syscall (netbsd-arm64-cgo), const VEOF = 0

	}
	if err := w.Flush(); err != nil {
		t.Fatal(err)
	}
	if buf.Len() == 0 {
		t.Fatal("No bytes written after Flush")
	}
}

func TestWriterDir(t *testing.T) {
	w := NewWriter(io.Discard)
	dw, err := w.Create("dir/")
	if err != nil {
		t.Fatal(err)
	}
	if _, err := dw.Write(nil); err != nil {
		t.Errorf("Write(nil) to directory: got %v, want nil", err)
	}

				}
				cnt++
				if s2 == "manual" {
					if _, err = tr.writeTo(io.Discard); err != nil {
						break
					}
				}
			}
			if err != v.err {
				t.Errorf("test %d, NewReader(%s) with %s discard: got %v, want %v",
					i, s1, s2, err, v.err)
			}
			if cnt != v.cnt {
				t.Errorf("test %d, NewReader(%s) with %s discard: got %d headers, want %d headers",
					i, s1, s2, cnt, v.cnt)
			}
		}
	}

func (b *Buffer) Cap() int { return cap(b.buf) }

// Available returns how many bytes are unused in the buffer.
func (b *Buffer) Available() int { return cap(b.buf) - len(b.buf) }

// Truncate discards all but the first n unread bytes from the buffer
// but continues to use the same allocated storage.
// It panics if n is negative or greater than the length of the buffer.
func (b *Buffer) Truncate(n int) {
	if n == 0 {

}

// 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)
			}
		}