Adding protection against a rare crash

diff --git a/PWGLF/totEt/AliAnalysisHadEtMonteCarlo.cxx b/PWGLF/totEt/AliAnalysisHadEtMonteCarlo.cxx
index a9cc54cafdfdfa68884bd020430104083cb99709..8f606ae7a66fcb39ed6d693a0bc342e75d4109f6 100644 (file)
--- a/PWGLF/totEt/AliAnalysisHadEtMonteCarlo.cxx
+++ b/PWGLF/totEt/AliAnalysisHadEtMonteCarlo.cxx
@@ -203,7 +203,7 @@ Int_t AliAnalysisHadEtMonteCarlo::AnalyseEvent(AliVEvent* ev,AliVEvent* ev2)
          FillHisto2D(Form("dEdxAll%s",cutName->Data()),track->P(),dEdx,1.0);
 
          UInt_t label = (UInt_t)TMath::Abs(track->GetLabel());
-         TParticle  *simPart  = stack->Particle(label);
+           TParticle  *simPart  = stack->Particle(label);
          if(!simPart) {
            Printf("no MC particle\n");                 
            continue;           
@@ -706,7 +706,8 @@ Int_t AliAnalysisHadEtMonteCarlo::AnalyseEvent(AliVEvent* ev,AliVEvent* ev2)
              if(isProton) myrecoEt = Et(track->P(),track->Theta(),fgProtonCode,track->Charge());
              if(isKaon) myrecoEt = Et(track->P(),track->Theta(),fgKPlusCode,track->Charge());
              if (TMath::Abs(simPart->Eta()) < fHadEtReco->GetCorrections()->GetEtaCut()){
-               TParticle *mom = stack->Particle(simPart->GetFirstMother());
+               TParticle *mom = NULL;
+               if(simPart->GetFirstMother()>=0) mom= stack->Particle(simPart->GetFirstMother());
                if(mom){
                  TParticlePDG *pc = mom->GetPDG(0);
                  if(pc){
@@ -832,7 +833,8 @@ Int_t AliAnalysisHadEtMonteCarlo::AnalyseEvent(AliVEvent* ev,AliVEvent* ev2)
                    }
 
                    if(mom->GetFirstMother()>0){
-                     TParticle *grandma = stack->Particle(mom->GetFirstMother());
+                     TParticle *grandma = NULL;
+                     if(mom->GetFirstMother()>=0) stack->Particle(mom->GetFirstMother());
                      if(grandma){
                        Int_t pdgCodeMom =  mom->GetPDG(0)->PdgCode();
                        if(pdgCodeMom==fgPiPlusCode || pdgCodeMom==fgPiMinusCode || pdgCodeMom==fgProtonCode ||pdgCodeMom==fgAntiProtonCode || pdgCodeMom==fgKPlusCode || pdgCode==fgKMinusCode){
@@ -1591,7 +1593,7 @@ Int_t AliAnalysisHadEtMonteCarlo::AnalyseEvent(AliVEvent* ev)
              Int_t pdgCodeMom = -99999999;
              float momEta = -30;
              float mompT = -5;
-             if(part->GetFirstMother()){
+             if(part->GetFirstMother()>=0){
                mom = stack->Particle(part->GetFirstMother());
                pdgCodeMom =  mom->GetPDG(0)->PdgCode();
                momEta = mom->Eta();