new files. **Do not add RELNOTE=yes comments in CLs.** Instead, add a file to
the CL (or ask the author to do so).

At the end of the development cycle, the files will be merged by being
concatenated in sorted order by pathname. Files in the directory matching the
glob "*stdlib/*minor" are treated specially. They should be in subdirectories
corresponding to standard library package paths, and headings for those package

		f := runtime.FuncForPC(pc[i] - 1) // TODO: use runtime.CallersFrames
		if f == nil {
			t.Fatalf("expected non-nil Func for pc %d", pc[i])
		}
		fname := f.Name()
		// Remove the prepended pathname from automatically
		// generated cgo function names.
		if strings.HasPrefix(fname, "_") {
			fname = path.Base(f.Name()[1:])
		}
		// In module mode, this package has a fully-qualified import path.

const (
	paxNone     = "" // Indicates that no PAX key is suitable
	paxPath     = "path"
	paxLinkpath = "linkpath"
	paxSize     = "size"
	paxUid      = "uid"
	paxGid      = "gid"
	paxUname    = "uname"
	paxGname    = "gname"
	paxMtime    = "mtime"
	paxAtime    = "atime"
	paxCtime    = "ctime"   // Removed from later revision of PAX spec, but was valid
	paxCharset  = "charset" // Currently unused

// The key must not contain an '=' character.
func validPAXRecord(k, v string) bool {
	if k == "" || strings.Contains(k, "=") {
		return false
	}
	switch k {
	case paxPath, paxLinkpath, paxUname, paxGname:
		return !hasNUL(v)
	default:
		return !hasNUL(k)
	}

		if v == "" {
			continue // Keep the original USTAR value
		}
		var id64 int64
		switch k {
		case paxPath:
			hdr.Name = v
		case paxLinkpath:
			hdr.Linkname = v
		case paxUname:
			hdr.Uname = v
		case paxGname:
			hdr.Gname = v
		case paxUid:
			id64, err = strconv.ParseInt(v, 10, 64)
			hdr.Uid = int(id64) // Integer overflow possible
		case paxGid:
			id64, err = strconv.ParseInt(v, 10, 64)

	}, {
		header:  &Header{Uname: "0123456789abcdef0123456789abcdef"},
		formats: FormatUSTAR | FormatPAX | FormatGNU,
	}, {
		header:  &Header{Uname: "0123456789abcdef0123456789abcdefx"},
		paxHdrs: map[string]string{paxUname: "0123456789abcdef0123456789abcdefx"},
		formats: FormatPAX,
	}, {
		header:  &Header{Name: "foobar"},
		formats: FormatUSTAR | FormatPAX | FormatGNU,
	}, {
		header:  &Header{Name: strings.Repeat("a", nameSize)},