return sub
		}
	}
	return nil
}

// hasFlag reports whether a command or any of its subcommands contain the given
// flag.
func hasFlag(c *Command, name string) bool {
	if f := c.Flag.Lookup(name); f != nil {
		return true
	}
	for _, sub := range c.Commands {
		if hasFlag(sub, name) {
			return true
		}
	}
	return false
}

			}
			Fatalf("go: parsing $GOFLAGS: non-flag %q", f)
		}

		name := f[1:]
		if name[0] == '-' {
			name = name[1:]
		}
		if i := strings.Index(name, "="); i >= 0 {
			name = name[:i]
		}
		if !hasFlag(Go, name) {
			if hideErrors {
				continue
			}
			Fatalf("go: parsing $GOFLAGS: unknown flag -%s", name)
		}
	}
}

// boolFlag is the optional interface for flag.Value known to the flag package.

func (h finishedHash) hashForClientCertificate(sigType uint8, hashAlg crypto.Hash) []byte {
	if (h.version >= VersionTLS12 || sigType == signatureEd25519) && h.buffer == nil {
		panic("tls: handshake hash for a client certificate requested after discarding the handshake buffer")
	}

	if sigType == signatureEd25519 {
		return h.buffer
	}

	if h.version >= VersionTLS12 {
		hash := hashAlg.New()
		hash.Write(h.buffer)