OpenSystemsDevelopment / qpdf

Commit e28625144d8eb77b98d3e64107aa0f353863def4

Authored by m-holger
Committed by Jay Berkenbilt
1 parent adb866ef

Tweak QPDF::getCompressibleObjGens

Inline Side-by-side
Showing 1 changed file with 12 additions and 7 deletions
libqpdf/QPDF.cc
  View file @e286251
... ... @@ -2398,7 +2398,6 @@ QPDF::getCompressibleObjGens()
2398 2398  
2399 2399 const size_t max_obj = getObjectCount();
2400 2400 std::vector<bool> visited(max_obj, false);
2401   - QPDFObjGen::set visited_gen; // for objects with generation > 0
2402 2401 std::vector<QPDFObjectHandle> queue;
2403 2402 queue.reserve(512);
2404 2403 queue.push_back(m->trailer);
... ... @@ -2409,19 +2408,25 @@ QPDF::getCompressibleObjGens()
2409 2408 if (obj.isIndirect()) {
2410 2409 QPDFObjGen og = obj.getObjGen();
2411 2410 const size_t id = toS(og.getObj() - 1);
2412   - const int gen = og.getGen();
2413 2411 if (id >= max_obj)
2414 2412 throw std::logic_error(
2415 2413 "unexpected object id encountered in getCompressibleObjGens");
2416   - if ((gen == 0 && visited[id]) || visited_gen.count(og)) {
  2414 + if (visited[id]) {
2417 2415 QTC::TC("qpdf", "QPDF loop detected traversing objects");
2418 2416 continue;
2419 2417 }
2420   - if (gen == 0) {
2421   - visited[id] = true;
2422   - } else {
2423   - visited_gen.insert(og);
  2418 +
  2419 + // Check whether this is the current object. If not, remove it (which changes it into a
  2420 + // direct null and therefore stops us from revisiting it) and move on to the next object
  2421 + // in the queue.
  2422 + auto upper = m->obj_cache.upper_bound(og);
  2423 + if (upper != m->obj_cache.end() && upper->first.getObj() == og.getObj()) {
  2424 + removeObject(og);
  2425 + continue;
2424 2426 }
  2427 +
  2428 + visited[id] = true;
  2429 +
2425 2430 if (og == encryption_dict_og) {
2426 2431 QTC::TC("qpdf", "QPDF exclude encryption dictionary");
2427 2432 } else if (!(obj.isStream() ||
... ...