# File lib/brakeman/util.rb, line 458
  def github_url file, line=nil
    if repo_url = @tracker.options[:github_url] and file and not file.empty? and file.start_with? '/'
      url = "#{repo_url}/#{relative_path(file)}"
      url << "#L#{line}" if line
    else
      nil
    end
  end