From 542e645bedec7702a973dc5cdaae87175e353009 Mon Sep 17 00:00:00 2001
From: Zahary Karadjov <zahary@gmail.com>
Date: Mon, 7 Mar 2022 17:24:21 +0200
Subject: [PATCH] Fix off-by-one error in determining the sync committee when
 POSTing sync committee messages through the REST API

---
 beacon_chain/validators/validator_duties.nim | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/beacon_chain/validators/validator_duties.nim b/beacon_chain/validators/validator_duties.nim
index 0ee548267..1073fff9d 100644
--- a/beacon_chain/validators/validator_duties.nim
+++ b/beacon_chain/validators/validator_duties.nim
@@ -268,7 +268,7 @@ proc sendSyncCommitteeMessages*(node: BeaconNode,
 
           for index, msg in msgs.pairs():
             if msg.validator_index < lenu64(state.data.validators):
-              let msgPeriod = sync_committee_period(msg.slot)
+              let msgPeriod = sync_committee_period(msg.slot + 1)
               if msgPeriod == curPeriod:
                 resCur[msg.validator_index] = index
               elif msgPeriod == nextPeriod: