From bea6add0d7a5c6ba8c774d431a3a78fb90d6730e Mon Sep 17 00:00:00 2001
From: exo-mv <exo-mv@users.noreply.github.com>
Date: Thu, 4 Jun 2026 13:44:14 +0000
Subject: [PATCH] fix(transaction): use arg.toObject() in fromObject for
 Transaction instances

fromObject called transaction.toObject() while the transaction variable was still undefined, so passing a Transaction instance threw "TypeError: Cannot read properties of undefined (reading 'toObject')". Read from the arg parameter, which holds the Transaction instance. Add a regression test for this previously uncovered path.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Co-authored-by: Claude Code (claude-opus-4-8[1m]) <noreply@anthropic.com>
---
 lib/transaction/transaction.js |  2 +-
 test/transaction/fromObject.js | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)
 create mode 100644 test/transaction/fromObject.js

diff --git a/lib/transaction/transaction.js b/lib/transaction/transaction.js
index f15043c..ee8499b 100644
--- a/lib/transaction/transaction.js
+++ b/lib/transaction/transaction.js
@@ -472,7 +472,7 @@ Transaction.prototype.fromObject = function fromObject(arg) {
   var self = this;
   var transaction;
   if (arg instanceof Transaction) {
-    transaction = transaction.toObject();
+    transaction = arg.toObject();
   } else {
     transaction = arg;
   }
diff --git a/test/transaction/fromObject.js b/test/transaction/fromObject.js
new file mode 100644
index 0000000..61c488e
--- /dev/null
+++ b/test/transaction/fromObject.js
@@ -0,0 +1,23 @@
+'use strict';
+
+require('chai').should();
+
+var bitcore = require('../../index-test');
+var Transaction = bitcore.Transaction;
+
+describe('Transaction', function() {
+
+  describe('#fromObject', function() {
+
+    it('builds from a Transaction instance and preserves its data', function() {
+      var source = new Transaction().lockUntilBlockHeight(123);
+
+      var target = new Transaction().fromObject(source);
+
+      target.nLockTime.should.equal(123);
+      target.toObject().should.deep.equal(source.toObject());
+    });
+
+  });
+
+});