PVS-Studio warning V501 for Firebird

bool CMP_node_match( const qli_nod* node1, const qli_nod* node2)
{
  ....
  if (node1->nod_desc.dsc_dtype != node2->nod_desc.dsc_dtype ||
      node2->nod_desc.dsc_scale != node2->nod_desc.dsc_scale ||
      node2->nod_desc.dsc_length != node2->nod_desc.dsc_length)
  ....
}

This suspicious code was found in Firebird project by PVS-Studio static code analyzer.
Warning message is:
V501 There are identical sub-expressions 'node2->nod_desc.dsc_scale' to the left and to the right of the '!=' operator. compile.cpp 156

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/