// Most notably, it cannot support sparse files, files larger than 8GiB,
	// filenames larger than 256 characters, and non-ASCII filenames.
	//
	// Reference:
	//	http://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13_06
	FormatUSTAR

	// FormatPAX represents the PAX header format defined in POSIX.1-2001.
	//

	// of the timezone used for the date fields), many competing extra fields
	// have been invented. Pervasive use effectively makes them "official".
	//
	// See http://mdfs.net/Docs/Comp/Archiving/Zip/ExtraField
	zip64ExtraID       = 0x0001 // Zip64 extended information
	ntfsExtraID        = 0x000a // NTFS
	unixExtraID        = 0x000d // UNIX
	extTimeExtraID     = 0x5455 // Extended timestamp

// (due to the printer possibly inserting newlines because of position
// information) operators.
var gofmtLineReplacer = strings.NewReplacer(
	// Want to replace \n without ; after everything from
	// https://golang.org/ref/spec#Operators_and_punctuation
	// EXCEPT ++ -- ) ] }
	"++\n", "++;",
	"--\n", "--;",

	"+\n", "+ ",
	"-\n", "- ",
	"*\n", "* ",
	"/\n", "/ ",
	"%\n", "% ",
	"&\n", "& ",

}

func (tw *Writer) writePAXHeader(hdr *Header, paxHdrs map[string]string) error {
	realName, realSize := hdr.Name, hdr.Size

	// TODO(dsnet): Re-enable this when adding sparse support.
	// See https://golang.org/issue/22735
	/*
		// Handle sparse files.
		var spd sparseDatas
		var spb []byte
		if len(hdr.SparseHoles) > 0 {
			sph := append([]sparseEntry{}, hdr.SparseHoles...) // Copy sparse map

// detect attempts to autodetect the correct
// values of the environment variables
// used by go_ios_exec.
// detect shells out to ideviceinfo, a third party program that can
// be obtained by following the instructions at
// https://github.com/libimobiledevice/libimobiledevice.
package main

import (
	"bytes"
	"crypto/x509"
	"fmt"
	"os"
	"os/exec"
	"strings"
)

func main() {

		}
	}
}

func TestSkipInternal(t *testing.T) {
	tests := []struct {
		pkg  string
		want bool
	}{
		{"net/http", true},
		{"net/http/internal-foo", true},
		{"net/http/internal", false},
		{"net/http/internal/bar", false},
		{"internal/foo", false},
		{"internal", false},
	}
	for _, tt := range tests {
		got := !internalPkg.MatchString(tt.pkg)

	if err != nil {
		t.Skipf("swig not in PATH: %s", err)
	}

	// Check that swig was installed with Go support by checking
	// that a go directory exists inside the swiglib directory.
	// See https://golang.org/issue/23469.
	output, err := exec.Command(swig, "-go", "-swiglib").Output()
	if err != nil {
		t.Skip("swig is missing Go support")
	}
	swigDir := strings.TrimSpace(string(output))

not be referenced from Go code; static functions are permitted.

See $GOROOT/cmd/cgo/internal/teststdio and $GOROOT/misc/cgo/gmp for examples. See
"C? Go? Cgo!" for an introduction to using cgo:
https://golang.org/doc/articles/c_go_cgo.html.

CFLAGS, CPPFLAGS, CXXFLAGS, FFLAGS and LDFLAGS may be defined with pseudo
#cgo directives within these comments to tweak the behavior of the C, C++

	r.buf = r.buf[read:]

	switch read {
	case 0, len(r.buf):
		// As allowed in the documentation, this will return io.EOF
		// in the same call that consumes the last of the data.
		// https://godoc.org/io#Reader
		return read, io.EOF
	}

	return read, nil
}

func TestPartialReadEOF(t *testing.T) {
	src := make([]byte, 10)
	eofR := &eofReader{buf: src}
	r := NewReader(eofR)

// If the allocation fails, it panics with ErrTooLarge.
func growSlice(b []byte, n int) []byte {
	defer func() {
		if recover() != nil {
			panic(ErrTooLarge)
		}
	}()
	// TODO(http://golang.org/issue/51462): We should rely on the append-make
	// pattern so that the compiler can call runtime.growslice. For example:
	//	return append(b, make([]byte, n)...)