message: Add protection to check if cocktail header exists
diff: @@ -719,6 +719,8 @@ void AliCFTaskVertexingHF::UserExec(Option_t *)
  Bool_t isHijing = kFALSE;
  // check if Hijing is among the generators used in the MC simulation
  TList *lgen = mcHeader->GetCocktailHeaders();
  + if(lgen)
  + {
  for(Int_t i=0;i<lgen->GetEntries();i++){
  AliGenEventHeader* gh=(AliGenEventHeader*)lgen->At(i);
  TString genname=gh->GetName();
  @@ -728,6 +730,7 @@ void AliCFTaskVertexingHF::UserExec(Option_t *)
  break;
  }
  }
  + }
  if(isHijing) {
  Bool_t isPileUp = AliAnalysisUtils::IsPileupInGeneratedEvent(mcHeader, "Hijing");
  