message: Do not rebuild GNU Hash table when it is empty
diff: @@ -794,6 +794,17 @@ void Builder::build_symbol_gnuhash(void) {
  const uint32_t maskwords = gnu_hash.maskwords();
  const uint32_t shift2 = gnu_hash.shift2();
  + const std::vector<uint64_t>& filters = gnu_hash.bloom_filters();
  + if (filters.size() > 0 and filters[0] == 0) {
  + VLOG(VDEBUG) << "Bloom filter is null: nothing to do!";
  + return;
  + }
  +
  + if (shift2 == 0) {
  + VLOG(VDEBUG) << "Shift2 is null: nothing to do!";
  + return;
  + }
  +
  VLOG(VDEBUG) << "Number of buckets " << std::dec << nb_buckets;
  VLOG(VDEBUG) << "First symbol idx " << std::dec << symndx;
  VLOG(VDEBUG) << "Number of bloom filters " << std::dec << maskwords;
  