uninstall_doc (Gem::DocManager)

    # File lib/rubygems/doc_manager.rb, line 122
        def uninstall_doc
          raise Gem::FilePermissionError.new(@spec.installation_path) unless
            File.writable? @spec.installation_path

          original_name = [
            @spec.name, @spec.version, @spec.original_platform].join '-'

          doc_dir = File.join @spec.installation_path, 'doc', @spec.full_name
          unless File.directory? doc_dir then
            doc_dir = File.join @spec.installation_path, 'doc', original_name
          end

          FileUtils.rm_rf doc_dir

          ri_dir = File.join @spec.installation_path, 'ri', @spec.full_name

          unless File.directory? ri_dir then
            ri_dir = File.join @spec.installation_path, 'ri', original_name
          end

          FileUtils.rm_rf ri_dir
        end