# File lib/rdoc/ri/paths.rb, line 69
  def self.gemdirs
    return @gemdirs if @gemdirs

    require 'rubygems' unless defined?(Gem)

    # HACK dup'd from Gem.latest_partials and friends
    all_paths = []

    all_paths = Gem.path.map do |dir|
      Dir[File.join(dir, 'doc', '*', 'ri')]
    end.flatten

    ri_paths = {}

    all_paths.each do |dir|
      base = File.basename File.dirname(dir)
      if base =~ /(.*)-((\d+\.)*\d+)/ then
        name, version = $1, $2
        ver = Gem::Version.new version
        if ri_paths[name].nil? or ver > ri_paths[name][0] then
          ri_paths[name] = [ver, dir]
        end
      end
    end

    @gemdirs = ri_paths.map { |k,v| v.last }.sort
  rescue LoadError
    @gemdirs = []
  end