From add868ce977e7a689eae8ef26cca8549cefaaf0b Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Mon, 14 Oct 2019 09:54:47 +0200
Subject: [PATCH] params: add nil-check before compare

---
 params/config.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/params/config.go b/params/config.go
index be8bb03bf6..0d1fe74901 100644
--- a/params/config.go
+++ b/params/config.go
@@ -483,6 +483,9 @@ func (c *ChainConfig) IsForkBlock(n uint64) bool {
 		c.PetersburgBlock,
 		c.IstanbulBlock,
 	} {
+		if forkNum == nil {
+			return false
+		}
 		h := number.Cmp(forkNum)
 		if h < 0 {
 			return false