GeneratorFilters: fix logic of the (xAOD)XtoVVDecayFilterExtended.cxx

GeneratorFilters: fix logic of the (xAOD)XtoVVDecayFilterExtended.cxx

Generators/GeneratorFilters/src/XtoVVDecayFilterExtended.cxx

 /*
-  Copyright (C) 2002-2023 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
 */
 
 #include "GeneratorFilters/XtoVVDecayFilterExtended.h"
@@ -103,7 +103,8 @@ bool XtoVVDecayFilterExtended::RunHistory(const HepMC::ConstGenParticlePtr& inpu
   if(std::abs(pitr->pdg_id()) != m_PDGGrandParent && std::abs(pitr->pdg_id()) != m_PDGParent) return false;
   if (result == m_PDGGrandParent) return true;
 
-  auto pitr_current = pitr->production_vertex()->particles_in().at(0);
+  // set pitr_current to grand parent pointer
+  auto pitr_current = pitr;
   while ( result >= 0 ) {
     pitr_current = CheckGrandparent(pitr_current, result);
     ATH_MSG_DEBUG("Pointer PDG ID: " << pitr->pdg_id());

Generators/GeneratorFilters/src/xAODXtoVVDecayFilterExtended.cxx

 /*
-  Copyright (C) 2002-2022 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
 */
 
 #include "GeneratorFilters/xAODXtoVVDecayFilterExtended.h"
@@ -122,7 +122,8 @@ bool xAODXtoVVDecayFilterExtended::RunHistory(const xAOD::TruthParticle *pitr)
     if (result == m_PDGGrandParent)
         return true;
 
-    auto pitr_current = pitr->prodVtx()->incomingParticle(0);
+    //set pitr_current to pitr of grand parent 
+    auto pitr_current = pitr;
     while (result >= 0)
     {
         pitr_current = CheckGrandparent(pitr_current, result);