From 74ffde83674f6a1af196ce7376816030c75bd0c5 Mon Sep 17 00:00:00 2001
From: Anna Shaleva <shaleva.ann@nspcc.ru>
Date: Wed, 15 Jul 2020 13:05:29 +0300
Subject: [PATCH] core: adjust System.Blockchain.GetTransactionFromBlock
 interop

To match C# implementation, we should pick all arguments from stack first.
---
 pkg/core/interop_system.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkg/core/interop_system.go b/pkg/core/interop_system.go
index 003c6acda..3d84b7d24 100644
--- a/pkg/core/interop_system.go
+++ b/pkg/core/interop_system.go
@@ -155,12 +155,12 @@ func bcGetTransactionFromBlock(ic *interop.Context, v *vm.VM) error {
 	if err != nil {
 		return err
 	}
+	index := v.Estack().Pop().BigInt().Int64()
 	block, err := ic.DAO.GetBlock(hash)
 	if err != nil || !isTraceableBlock(ic, block.Index) {
 		v.Estack().PushVal(stackitem.Null{})
 		return nil
 	}
-	index := v.Estack().Pop().BigInt().Int64()
 	if index < 0 || index >= int64(len(block.Transactions)) {
 		return errors.New("wrong transaction index")
 	}