PVS-Studio warning V522 for NetXMS

void ClientSession::findIpAddress(CSCPMessage *request)
{
  ....
  if (subnet != NULL)
  {
    debugPrintf(5, _T("findIpAddress(%s): found subnet %s"),
                ipAddrText,
                subnet->Name());
    found = subnet->findMacAddress(ipAddr, macAddr);
  }
  else
  {
    debugPrintf(5, _T("findIpAddress(%s): subnet not found"),
                ipAddrText,
                subnet->Name());
  }
  ....
}

This suspicious code was found in NetXMS project by PVS-Studio static code analyzer.
Warning message is:
V522 Dereferencing of the null pointer 'subnet' might take place. session.cpp 10823

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/