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

	}
	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 {

		p.symDefRef(w, word, operands)
	}
	return p.errorCount == 0
}

// nextToken returns the next non-build-comment token from the lexer.
// It reports misplaced //go:build comments but otherwise discards them.
func (p *Parser) nextToken() lex.ScanToken {
	for {
		tok := p.lex.Next()
		if tok == lex.BuildComment {
			if p.sawCode {
				p.errorf("misplaced //go:build comment")
			}
			continue
		}

			err = ErrBufferFull
		}
	}
	return b.buf[b.r : b.r+n], err
}

// Discard skips the next n bytes, returning the number of bytes discarded.
//
// If Discard skips fewer than n bytes, it also returns an error.
// If 0 <= n <= b.Buffered(), Discard is guaranteed to succeed without
// reading from the underlying io.Reader.
func (b *Reader) Discard(n int) (discarded int, err error) {
	if n < 0 {
		return 0, ErrNegativeCount
	}

	// one or more "header files" until it finds a "normal file".
	format := FormatUSTAR | FormatPAX | FormatGNU
	for {
		// Discard the remainder of the file and any padding.
		if err := discard(tr.r, tr.curr.physicalRemaining()); err != nil {
			return nil, err
		}
		if _, err := tryReadFull(tr.r, tr.blk[:tr.pad]); err != nil {
			return nil, err
		}
		tr.pad = 0

		for _, v := range vectors {
			b.Run(v.label, func(b *testing.B) {
				b.ReportAllocs()
				for i := 0; i < b.N; i++ {
					// Writing to io.Discard because we want to
					// test purely the writer code and not bring in disk performance into this.
					tw := NewWriter(io.Discard)
					for _, file := range v.files {
						if err := tw.WriteHeader(file.hdr); err != nil {
							b.Errorf("unexpected WriteHeader error: %v", err)

</p>

<p>
Not allowing a single read to observe multiple values means
not reloading local variables from shared memory.
For example, a compiler must not discard <code>i</code> and reload it
a second time from <code>*p</code> in this program:
</p>

<pre>
i := *p
if i &lt; 0 || i &gt;= len(funcs) {
	panic("invalid function index")
}
... complex code ...

	}, {
		name: "PAX header too long",
		h:    &Header{PAXRecords: map[string]string{"GOLANG.x": strings.Repeat("a", maxSpecialFileSize)}},
	}} {
		w := NewWriter(io.Discard)
		if err := w.WriteHeader(test.h); err != ErrFieldTooLong {
			t.Errorf("%v: w.WriteHeader() = %v, want ErrFieldTooLong", test.name, err)
		}
	}
}