# File lib/yard/registry.rb, line 51
      def yardoc_file_for_gem(gem, ver_require = ">= 0", for_writing = false)
        spec = Gem.source_index.find_name(gem, ver_require)
        return if spec.empty?
        spec = spec.first

        if gem =~ /^yard-doc-/
          path = File.join(spec.full_gem_path, DEFAULT_YARDOC_FILE)
          return File.exist?(path) && !for_writing ? path : nil
        end

        if for_writing
          global_yardoc_file(spec, for_writing) ||
            local_yardoc_file(spec, for_writing)
        else
          local_yardoc_file(spec, for_writing) ||
            global_yardoc_file(spec, for_writing)
        end
      end