message: EMCal Embed: Fix TRefArray errors in matching
  See comments in the code for further details, but it was caused
  by adding tracks from different collections which had different
  TProcessIDs
diff: @@ -290,6 +290,7 @@ void AliEmcalCorrectionClusterTrackMatcher::GenerateEmcalParticles()
  // use pion mass, and fUseDCA to determine starting point of propagation
  mass = 0.1396;
  }
  +
  AliParticleContainer * partCont = 0;
  TIter nextPartCont(&fParticleCollArray);
  while ((partCont = static_cast<AliParticleContainer*>(nextPartCont()))) {
  @@ -336,13 +337,24 @@ void AliEmcalCorrectionClusterTrackMatcher::GenerateEmcalParticles()
  AliEMCALRecoUtils::ExtrapolateTrackToEMCalSurface(track, fPropDist, mass, 20, 0.35, kFALSE, fUseDCA);
  }
  + // Reset properties of the track to fix TRefArray errors which occur when AddTrackMatched(obj) is called.
  + // This particular combination is from AODTrackFilterTask
  + // Resetting just the TProcessID of the track is not sufficient!
  + // It is included here because multiple track collections can come from different files with different
  + // Process IDs (for example, when embedding). As long as the updated tracks are not stored in a file,
  + // (normally they are not) then resetting these values won't adversely change the behavior of the code
  + // (except for fixing the TRefArray errors).
  + track->SetUniqueID(0);
  + track->ResetBit(TObject::kHasUUID);
  + track->ResetBit(TObject::kIsReferenced);
  +
  // Create AliEmcalParticle objects to handle the matching
  AliEmcalParticle* emcalTrack = new ((*fEmcalTracks)[fNEmcalTracks]) AliEmcalParticle(track, fParticleContainerIndexMap.GlobalIndexFromLocalIndex(partCont, partIterator.current_index()));
  emcalTrack->SetMatchedPtr(fEmcalClusters);
  - AliDebug(2, Form("Now adding track (pT = %.3f, eta = %.3f, phi = %.3f)"
  + AliDebug(2, Form("Now adding track %i (pT = %.3f, eta = %.3f, phi = %.3f)"
  "Phi, Eta on EMCal = %.3f, %.3f",
  - emcalTrack->Pt(), emcalTrack->Eta(), emcalTrack->Phi(),
  + emcalTrack->IdInCollection(), emcalTrack->Pt(), emcalTrack->Eta(), emcalTrack->Phi(),
  track->GetTrackEtaOnEMCal(), track->GetTrackPhiOnEMCal()));
  fNEmcalTracks++;
  