From 0fabe06667d8b41910aafe515054d45c78fff065 Mon Sep 17 00:00:00 2001
From: Paul Miller <paul@paulmillr.com>
Date: Sat, 23 Nov 2024 08:42:23 +0000
Subject: [PATCH] Improve p2wpkh behavior when inputSighash is undefined

---
 src/transaction.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/transaction.ts b/src/transaction.ts
index 952c680..4732551 100644
--- a/src/transaction.ts
+++ b/src/transaction.ts
@@ -381,7 +381,8 @@ export class Transaction {
   // We will lose some vectors -> smaller test coverage of preimages (very important!)
   private inputSighash(idx: number) {
     this.checkInputIdx(idx);
-    const sighash = getInputType(this.inputs[idx], this.opts.allowLegacyWitnessUtxo).sighash;
+    const inputSighash = this.inputs[idx].sighashType;
+    const sighash = inputSighash === undefined ? SignatureHash.DEFAULT : inputSighash;
     // ALL or DEFAULT -- everything signed
     // NONE           -- all inputs + no outputs
     // SINGLE         -- all inputs + output with same index