code: def _proc_gnulong(self, tarfile):
          
          buf = tarfile.fileobj.read(self._block(self.size))
  
          # Fetch the next header and process it.
          try:
              next = self.fromtarfile(tarfile)
          except HeaderError:
              raise SubsequentHeaderError("missing or bad subsequent header")
  
          # Patch the TarInfo object from the next header with
          # the longname information.
          next.offset = self.offset
          if self.type == GNUTYPE_LONGNAME:
              next.name = nts(buf, tarfile.encoding, tarfile.errors)
          elif self.type == GNUTYPE_LONGLINK:
              next.linkname = nts(buf, tarfile.encoding, tarfile.errors)
  
          return next
docs: Process the blocks that hold a GNU longname
             or longlink member.