From 5d52968dd4da4b544a94f54a15710cb9c1bef2a3 Mon Sep 17 00:00:00 2001
From: mandrenguyen <Matthew.Nguyen@cer.ch>
Date: Wed, 29 Sep 2021 13:10:09 +0200
Subject: [PATCH] Set collisionId in prunedGenParticles

---
 PhysicsTools/HepMCCandAlgos/plugins/GenParticlePruner.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/PhysicsTools/HepMCCandAlgos/plugins/GenParticlePruner.cc b/PhysicsTools/HepMCCandAlgos/plugins/GenParticlePruner.cc
index 5bbb30b05092d..31e0eb57a65c3 100644
--- a/PhysicsTools/HepMCCandAlgos/plugins/GenParticlePruner.cc
+++ b/PhysicsTools/HepMCCandAlgos/plugins/GenParticlePruner.cc
@@ -255,6 +255,7 @@ void GenParticlePruner::produce(Event &evt, const EventSetup &es) {
     GenParticle &newGen = out->back();
     //fill status flags
     newGen.statusFlags() = gen.statusFlags();
+    newGen.setCollisionId(gen.collisionId());
     // The "daIndxs" and "moIndxs" keep a list of the keys for the mother/daughter
     // parentage/descendency. In some cases, a circular referencing is encountered,
     // which would result in an infinite loop. The list is checked to