From 36c6c6690b19f2b75a4a4e1ed522ee2adb3e05f0 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Sun, 26 Apr 2020 12:51:17 +0300
Subject: [PATCH] native: distribute GAS even for empty transfers

As it's one of the use cases.
---
 pkg/core/native/native_neo.go | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/pkg/core/native/native_neo.go b/pkg/core/native/native_neo.go
index 9e480e0ff..c77e679fe 100644
--- a/pkg/core/native/native_neo.go
+++ b/pkg/core/native/native_neo.go
@@ -158,14 +158,15 @@ func (n *NEO) increaseBalance(ic *interop.Context, h util.Uint160, si *state.Sto
 	if err != nil {
 		return err
 	}
-	if sign := amount.Sign(); sign == 0 {
-		return nil
-	} else if sign == -1 && acc.Balance.Cmp(new(big.Int).Neg(amount)) == -1 {
+	if amount.Sign() == -1 && acc.Balance.Cmp(new(big.Int).Neg(amount)) == -1 {
 		return errors.New("insufficient funds")
 	}
 	if err := n.distributeGas(ic, h, acc); err != nil {
 		return err
 	}
+	if amount.Sign() == 0 {
+		return nil
+	}
 	acc.Balance.Add(&acc.Balance, amount)
 	si.Value = acc.Bytes()
 	return nil