Incorrect vector construction in pgsql selection of historic nodes/ways/relations

[Woazboat]

When selecting historic nodes/ways/relations from the pgsql database, the id and version vectors are created via

  std::vector<osm_nwr_id_t> ids(eds.size());
  std::vector<osm_version_t> vers(eds.size());

  for (const auto &ed : eds) {
    ids.emplace_back(ed.first);
    vers.emplace_back(ed.second);
  }

https://github.com/zerebubuth/openstreetmap-cgimap/blob/master/src/backend/apidb/readonly_pgsql_selection.cpp#L577-L578

Presumably the vector is intended to be constructed with an appropriated pre-allocated/reserved size, but unfortunately the used vector( size_type count ); constructor actually fills the vector with count default inserted elements. That means the ids/vers vectors are created with eds.size() elements with value 0 and then the real id/version elements are inserted in addition.
reserve(eds.size()) should be used instead (which is actually how it used to be previously)

https://en.cppreference.com/w/cpp/container/vector/vector (4)

[mmd-osm]

Thanks, good catch, this should have been reserve instead, similar issues further down the in the same file. As we don’t have object / version 0 in the database, it won’t change the result.