read_until_dashes

# File lib/rubygems/package/old.rb, line 109
  def read_until_dashes io # :nodoc:
    while (line = io.gets) && line.chomp.strip != "---" do
      yield line if block_given?
    end
  end

  ##
  # Skips the Ruby self-install header in +io+.

  def skip_ruby io # :nodoc:
    loop do
      line = io.gets

      return if line.chomp == '__END__'
      break unless line
    end

    raise Gem::Exception, "Failed to find end of ruby script while reading gem"
  end

  ##
  # The specification for this gem

  def spec
    verify

    return @spec if @spec

    yaml = ''

    open @gem, 'rb' do |io|
      skip_ruby io
      read_until_dashes io do |line|
        yaml << line
      end
    end

    yaml_error = if RUBY_VERSION < '1.9' then
                   YAML::ParseError
                 elsif YAML::ENGINE.yamler == 'syck' then
                   YAML::ParseError
                 else
                   YAML::SyntaxError
                 end

    begin
      @spec = Gem::Specification.from_yaml yaml
    rescue yaml_error => e
      raise Gem::Exception, "Failed to parse gem specification out of gem file"
    end
  rescue ArgumentError => e
    raise Gem::Exception, "Failed to parse gem specification out of gem file"
  end

  ##
  # Raises an exception if a security policy that verifies data is active.
  # Old format gems cannot be verified as signed.

  def verify
    return true unless @security_policy

    raise Gem::Security::Exception,
          'old format gems do not contain signatures and cannot be verified' if
      @security_policy.verify_data

    true
  end

end