message: If generator is cocktail don't add spectators
diff: @@ -311,6 +311,7 @@ void AliZDCDigitizer::Digitize(Option_t* /*option*/)
  AliGenEventHeader* genHeader = header->GenEventHeader();
  if(!genHeader) continue;
  AliGenHijingEventHeader *hijingHeader = 0;
  + Bool_t isCocktail=kFALSE;
  if(genHeader->InheritsFrom(AliGenHijingEventHeader::Class())) hijingHeader = dynamic_cast <AliGenHijingEventHeader*> (genHeader);
  else if(genHeader->InheritsFrom(AliGenCocktailEventHeader::Class())){
  TList* listOfHeaders = ((AliGenCocktailEventHeader*) genHeader)->GetHeaders();
  @@ -319,6 +320,7 @@ void AliZDCDigitizer::Digitize(Option_t* /*option*/)
  AliGenEventHeader *currHeader = dynamic_cast <AliGenEventHeader *> (listOfHeaders->At(iH));
  if (currHeader && currHeader->InheritsFrom(AliGenHijingEventHeader::Class())) {
  hijingHeader = dynamic_cast <AliGenHijingEventHeader*> (currHeader);
  + isCocktail = kTRUE;
  break;
  }
  }
  @@ -331,7 +333,7 @@ void AliZDCDigitizer::Digitize(Option_t* /*option*/)
  printf(" No HIJING header found in list of headers from generator\n");
  }
  - if(hijingHeader && (!hijingHeader->GetSpectatorsInTheStack())){
  + if(hijingHeader && (!hijingHeader->GetSpectatorsInTheStack()) && !isCocktail){
  impPar = hijingHeader->ImpactParameter();
  Int_t freeSpecNProj=0, freeSpecPProj=0;
  Int_t freeSpecNTarg=0, freeSpecPTarg=0;
  