# File lib/yard/registry.rb, line 52
      def yardoc_file_for_gem(gem, ver_require = ">= 0", for_writing = false)
        specs = Gem.source_index.find_name(gem, ver_require)
        return if specs.empty?

        result = nil
        specs.reverse.each do |spec|
          if gem =~ /^yard-doc-/
            path = File.join(spec.full_gem_path, DEFAULT_YARDOC_FILE)
            result = File.exist?(path) && !for_writing ? path : nil
            result ? break : next
          end

          if for_writing
            result = global_yardoc_file(spec, for_writing) ||
              old_global_yardoc_file(spec, for_writing) ||
              local_yardoc_file(spec, for_writing)
          else
            result = local_yardoc_file(spec, for_writing) ||
              global_yardoc_file(spec, for_writing) ||
              old_global_yardoc_file(spec, for_writing)
          end

          break if result
        end

        result
      end