ensure sensible output in CellID for old files

Event/EventPacker/src/lib/PackedProtoParticle.cpp

@@ -164,6 +164,13 @@ StatusCode ProtoParticlePacker::unpack( const PackedData& pproto, Data& proto, c
     }
   }
 
+  auto CellIDFromAdditionalInfo = []( auto v ) {
+    double ai = StandardPacker::fltPacked( v );
+    auto   id = LHCb::Detector::Calo::CellID( ai >= 0. ? (unsigned)ai : 0u );
+    if ( !isValid( id ) ) id = LHCb::Detector::Calo::CellID{};
+    return id;
+  };
+
   // if the proto is charged-like, unpack CaloChargedPID and BremInfo. If we are in old version without CaloChargedPID
   // and BremInfo objects, create them from AdditionalInfo
   if ( -1 != pproto.track ) {
@@ -178,7 +185,7 @@ StatusCode ProtoParticlePacker::unpack( const PackedData& pproto, Data& proto, c
           pid->setInEcal( StandardPacker::fltPacked( v ) );
           break;
         case LHCb::ProtoParticle::CaloChargedID:
-          pid->setClusterID( Detector::Calo::CellID( StandardPacker::fltPacked( v ) ) );
+          pid->setClusterID( CellIDFromAdditionalInfo( v ) );
           break;
         case LHCb::ProtoParticle::CaloTrMatch:
           pid->setClusterMatch( StandardPacker::fltPacked( v ) );
@@ -219,7 +226,7 @@ StatusCode ProtoParticlePacker::unpack( const PackedData& pproto, Data& proto, c
           binfo->setInBrem( StandardPacker::fltPacked( v ) );
           break;
         case LHCb::ProtoParticle::CaloBremHypoID:
-          binfo->setBremHypoID( Detector::Calo::CellID( StandardPacker::fltPacked( v ) ) );
+          binfo->setBremHypoID( CellIDFromAdditionalInfo( v ) );
           break;
         case LHCb::ProtoParticle::CaloBremMatch:
           binfo->setBremHypoMatch( StandardPacker::fltPacked( v ) );
@@ -301,7 +308,7 @@ StatusCode ProtoParticlePacker::unpack( const PackedData& pproto, Data& proto, c
         pid->setCaloNeutralE49( StandardPacker::fltPacked( v ) );
         break;
       case LHCb::ProtoParticle::CaloNeutralID:
-        pid->setCaloNeutralID( LHCb::Detector::Calo::CellID( StandardPacker::fltPacked( v ) ) );
+        pid->setCaloNeutralID( CellIDFromAdditionalInfo( v ) );
         break;
       case LHCb::ProtoParticle::CaloNeutralE19:
         pid->setCaloNeutralE19( StandardPacker::fltPacked( v ) );