From bb530efa1872ec963417f61da9a95185c7a7a7d6 Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter.wuille@gmail.com>
Date: Thu, 23 Aug 2018 17:01:14 -0700
Subject: [PATCH] Disallow extended encoding for non-witness transactions

---
 src/primitives/transaction.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/primitives/transaction.h b/src/primitives/transaction.h
index fb9db508d25ee..c1568f9b2ac1b 100644
--- a/src/primitives/transaction.h
+++ b/src/primitives/transaction.h
@@ -220,6 +220,10 @@ inline void UnserializeTransaction(TxType& tx, Stream& s) {
         for (size_t i = 0; i < tx.vin.size(); i++) {
             s >> tx.vin[i].scriptWitness.stack;
         }
+        if (!tx.HasWitness()) {
+            /* It's illegal to encode witnesses when all witness stacks are empty. */
+            throw std::ios_base::failure("Superfluous witness record");
+        }
     }
     if (flags) {
         /* Unknown flag in the serialization */