conf.search = dnsDefaultSearch()
	}
	return conf
}

func dnsDefaultSearch() []string {
	hn, err := getHostname()
	if err != nil {
		// best effort
		return nil
	}
	if i := bytealg.IndexByteString(hn, '.'); i >= 0 && i < len(hn)-1 {
		return []string{ensureRooted(hn[i+1:])}
	}
	return nil
}

func ensureRooted(s string) string {
	if len(s) > 0 && s[len(s)-1] == '.' {
		return s
	}

// It's hard to tell so we settle on the heuristic that names without dots
// (like "localhost" or "myhost") do not get trailing dots, but any other
// names do.
func absDomainName(s string) string {
	if bytealg.IndexByteString(s, '.') != -1 && s[len(s)-1] != '.' {
		s += "."
	}
	return s
}

// An SRV represents a single DNS SRV record.
type SRV struct {
	Target   string
	Port     uint16
	Priority uint16

		switch path[i] {
		case ':', '\\', 0:
			return "", errInvalidPath
		}
	}
	containsSlash := false
	for p := path; p != ""; {
		// Find the next path element.
		var element string
		i := bytealg.IndexByteString(p, '/')
		if i < 0 {
			element = p
			p = ""
		} else {
			containsSlash = true
			element = p[:i]
			p = p[i+1:]
		}
		if isReservedName(element) {
			return "", errInvalidPath
		}
	}

func parsegodebug(godebug string, seen map[string]bool) {
	for p := godebug; p != ""; {
		var field string
		if seen == nil {
			// startup: process left to right, overwriting older settings with newer
			i := bytealg.IndexByteString(p, ',')
			if i < 0 {
				field, p = p, ""
			} else {
				field, p = p[:i], p[i+1:]
			}
		} else {
			// incremental update: process right to left, updating and skipping seen
			i := len(p) - 1

// concatenation.
func funcNamePiecesForPrint(name string) (string, string, string) {
	// Replace the shape name in generic function with "...".
	i := bytealg.IndexByteString(name, '[')
	if i < 0 {
		return name, "", ""
	}
	j := len(name) - 1
	for name[j] != ']' {
		j--
	}
	if j <= i {
		return name, "", ""
	}
	return name[:i], "[...]", name[j+1:]
}

	// of the string, but trying to handle it inline makes a bunch of
	// other inner loop conditionals more expensive, and it ends up
	// being slower.
	zone := ""
	i := bytealg.IndexByteString(s, '%')
	if i != -1 {
		s, zone = s[:i], s[i+1:]
		if zone == "" {
			// Not allowed to have an empty zone if explicitly specified.
			return Addr{}, parseAddrError{in: in, msg: "zone must be a non-empty string"}