# File lib/ole/storage/base.rb, line 471
      def chain idx
        a = []
        until idx >= META_BAT
          raise FormatError, "broken allocationtable chain" if idx < 0 || idx > length
          a << idx
          idx = self[idx]
        end
        Log.warn "invalid chain terminator #{idx}" unless idx == EOC
        a
      end