// which names a file in the testdata/ directory containing the
	// uncompressed expected content.
	// If content is very large, an alternative to setting Content or File
	// is to set Size, which will then be checked against the header-reported size
	// but will bypass the decompressing of the actual data.
	// This last option is used for testing very large (multi-GB) compressed files.
	ContentErr error
	Content    []byte
	File       string

The Go code can then refer to types such as C.size_t, variables such
as C.stdout, or functions such as C.putchar.

If the import of "C" is immediately preceded by a comment, that
comment, called the preamble, is used as a header when compiling
the C parts of the package. For example:

	// #include <stdio.h>
	// #include <errno.h>
	import "C"

The preamble may contain any C code, including function and variable

// For forward compatibility, users that retrieve a Header from Reader.Next,
// mutate it in some ways, and then pass it back to Writer.WriteHeader
// should do so by creating a new Header and copying the fields
// that they are interested in preserving.
type Header struct {
	// Typeflag is the type of header entry.
	// The zero value is automatically promoted to either TypeReg or TypeDir
	// depending on the presence of a trailing slash in Name.

If the argument to [FileInfoHeader] implements the new [FileInfoNames]
interface, then the interface methods will be used to set the Uname/Gname
of the file header. This allows applications to override the system-dependent

denial of service attacks, this setting and default was backported to Go
1.19.13, Go 1.20.8, and Go 1.21.1.

Go 1.22 made it an error for a request or response read by a net/http
client or server to have an empty Content-Length header.
This behavior is controlled by the `httplaxcontentlength` setting.

Go 1.22 changed the behavior of ServeMux to accept extended
patterns and unescape both patterns and request paths by segment.

`Make[T]` function, which produces a reference to a canonical copy of
the value in the form of a `Handle[T]`.
Two `Handle[T]` are equal if and only if the values used to produce the
handles are equal, allowing programs to deduplicate values and reduce
their memory footprint.
Comparing two `Handle[T]` values is efficient, reducing down to a simple

	}
}

func testValidHeader(h *FileHeader, t *testing.T) {
	var buf bytes.Buffer
	z := NewWriter(&buf)

	f, err := z.CreateHeader(h)
	if err != nil {
		t.Fatalf("error creating header: %v", err)
	}
	if _, err := f.Write([]byte("hi")); err != nil {
		t.Fatalf("error writing content: %v", err)
	}
	if err := z.Close(); err != nil {
		t.Fatalf("error closing zip writer: %v", err)
	}

	}, {
		header:  &Header{Mode: 07777777},
		formats: FormatUSTAR | FormatPAX | FormatGNU,
	}, {
		header:  &Header{Mode: 07777777 + 1},
		formats: FormatGNU,
	}, {
		header:  &Header{Devmajor: -123},
		formats: FormatGNU,
	}, {
		header:  &Header{Devmajor: 1<<56 - 1},
		formats: FormatGNU,
	}, {
		header:  &Header{Devmajor: 1 << 56},
		formats: FormatUnknown,
	}, {
		header:  &Header{Devmajor: -1 << 56},

}

// readGNUSparsePAXHeaders checks the PAX headers for GNU sparse headers.
// If they are found, then this function reads the sparse map and returns it.
// This assumes that 0.0 headers have already been converted to 0.1 headers
// by the PAX header parsing logic.
func (tr *Reader) readGNUSparsePAXHeaders(hdr *Header) (sparseDatas, error) {
	// Identify the version of GNU headers.
	var is1x0 bool

type Writer struct {
	cw          *countWriter
	dir         []*header
	last        *fileWriter
	closed      bool
	compressors map[uint16]Compressor
	comment     string

	// testHookCloseSizeOffset if non-nil is called with the size
	// of offset of the central directory at Close.
	testHookCloseSizeOffset func(size, offset uint64)
}

type header struct {
	*FileHeader
	offset uint64
	raw    bool
}