From a7fe85a2d89b3bea3ee67f12c24e1496e363faee Mon Sep 17 00:00:00 2001
From: Anna Shaleva <shaleva.ann@nspcc.ru>
Date: Tue, 5 Apr 2022 15:12:40 +0300
Subject: [PATCH] services: fix changing of main tx size of Notary request

---
 pkg/services/notary/notary.go | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/pkg/services/notary/notary.go b/pkg/services/notary/notary.go
index 5f6a8e747..f6537ac5b 100644
--- a/pkg/services/notary/notary.go
+++ b/pkg/services/notary/notary.go
@@ -218,8 +218,15 @@ func (n *Notary) OnNewRequest(payload *payload.P2PNotaryRequest) {
 			r.minNotValidBefore = nvbFallback
 		}
 	} else {
+		// Avoid changes in main transaction witnesses got from notary request pool to
+		// keep the pooled tx valid. We will update its copy => the copy's size will be changed.
+		cp := *payload.MainTransaction
+		cp.Scripts = make([]transaction.Witness, len(payload.MainTransaction.Scripts))
+		for i, w := range payload.MainTransaction.Scripts {
+			cp.Scripts[i] = w
+		}
 		r = &request{
-			main:              payload.MainTransaction,
+			main:              &cp,
 			minNotValidBefore: nvbFallback,
 		}
 		n.requests[payload.MainTransaction.Hash()] = r
@@ -227,6 +234,8 @@ func (n *Notary) OnNewRequest(payload *payload.P2PNotaryRequest) {
 	if r.witnessInfo == nil && validationErr == nil {
 		r.witnessInfo = newInfo
 	}
+	// Allow modification of fallback transaction got from notary request pool.
+	// It has dummy Notary witness attached => its size won't be changed.
 	r.fallbacks = append(r.fallbacks, payload.FallbackTransaction)
 	if exists && r.isMainCompleted() || validationErr != nil {
 		return