From 66ca654b0704c7d3bd5b1932cb6bf73f8a3fb1f8 Mon Sep 17 00:00:00 2001
From: Anna Shaleva <shaleva.ann@nspcc.ru>
Date: Tue, 29 Sep 2020 12:21:51 +0300
Subject: [PATCH] vm: refactor ISNULL opcode handling

---
 pkg/vm/vm.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pkg/vm/vm.go b/pkg/vm/vm.go
index 0aa99207b..ffc9332e6 100644
--- a/pkg/vm/vm.go
+++ b/pkg/vm/vm.go
@@ -531,8 +531,8 @@ func (v *VM) execute(ctx *Context, op opcode.Opcode, parameter []byte) (err erro
 		v.estack.PushVal(stackitem.Null{})
 
 	case opcode.ISNULL:
-		res := v.estack.Pop().value.Equals(stackitem.Null{})
-		v.estack.PushVal(res)
+		_, ok := v.estack.Pop().value.(stackitem.Null)
+		v.estack.PushVal(ok)
 
 	case opcode.ISTYPE:
 		res := v.estack.Pop().Item()