From 89f8a4350921822305a3da3c6ceac8e4adf1cef8 Mon Sep 17 00:00:00 2001
From: "alex.sharov" <AskAlexSharov@gmail.com>
Date: Tue, 10 Jan 2023 09:57:52 +0700
Subject: [PATCH] parallel warmup to exit early if nil

---
 eth/stagedsync/stage_hashstate.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/eth/stagedsync/stage_hashstate.go b/eth/stagedsync/stage_hashstate.go
index 44cace509..52b01b358 100644
--- a/eth/stagedsync/stage_hashstate.go
+++ b/eth/stagedsync/stage_hashstate.go
@@ -307,6 +307,9 @@ func parallelTransform(ctx context.Context, in chan pair, out chan pair, transfo
 }
 
 func parallelWarmup(ctx context.Context, db kv.RoDB, bucket string, workers int) error {
+	if db == nil || ctx == nil || workers == 0 {
+		return nil
+	}
 	g, ctx := errgroup.WithContext(ctx)
 	g.SetLimit(workers)
 	for i := 0; i < 256; i++ {