Don't attempt to access the LHCbIDs of neutrals when TOS matching in HltEfficiencyChecker

Phys/DecayTreeTuple/src/MCTupleToolTOSHLT2.cpp

@@ -70,7 +70,14 @@ void MCTupleToolTOSHLT2::fetchLHCbIDsFromRecoParticle( const LHCb::Particle& par
 
   if ( part.isBasicParticle() ) {
     // We can just get the protoparticle and its IDs
+    if ( part.charge() == 0 ) {
+      warning() << "Particle with ID " << part.particleID()
+                << " is neutral, so has no track. Adding empty container of LHCbIDs to this candidate for this track."
+                << endmsg;
+      bucket_of_ids.emplace_back();
+    } else {
       bucket_of_ids.emplace_back( part.proto()->track()->lhcbIDs() );
+    }
   } else {
     const auto& children = part.daughters();
     for ( const auto& child : children ) { fetchLHCbIDsFromRecoParticle( *child, bucket_of_ids ); }