From 9e9d59b49a5107626ee6e5a2c02be3364f3f293e Mon Sep 17 00:00:00 2001
From: Evgenii Stratonikov <evgeniy@nspcc.ru>
Date: Fri, 28 Feb 2020 11:49:14 +0300
Subject: [PATCH] core: set NetworkFee to 0 for Claim and Miner transactions

Claim tx have no GAS inputs and a positive output which
can lead to negative network fee.
---
 pkg/core/blockchain.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/pkg/core/blockchain.go b/pkg/core/blockchain.go
index a7d8c0f5b..b8a53c393 100644
--- a/pkg/core/blockchain.go
+++ b/pkg/core/blockchain.go
@@ -1168,6 +1168,11 @@ func (bc *Blockchain) FeePerByte(t *transaction.Transaction) util.Fixed8 {
 
 // NetworkFee returns network fee.
 func (bc *Blockchain) NetworkFee(t *transaction.Transaction) util.Fixed8 {
+	// https://github.com/neo-project/neo/blob/master-2.x/neo/Network/P2P/Payloads/ClaimTransaction.cs#L16
+	if t.Type == transaction.ClaimType || t.Type == transaction.MinerType {
+		return 0
+	}
+
 	inputAmount := util.Fixed8FromInt64(0)
 	refs, err := bc.References(t)
 	if err != nil {