From 9dfc61d95f0082672a9b90528386e6bcd7014a78 Mon Sep 17 00:00:00 2001
From: Sjors Provoost <sjors@sprovoost.nl>
Date: Fri, 13 Jun 2025 09:40:23 +0200
Subject: [PATCH] test: detect no external signer connected

---
 test/functional/mocks/no_signer.py | 29 +++++++++++++++++++++++++++++
 test/functional/wallet_signer.py   | 27 +++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)
 create mode 100755 test/functional/mocks/no_signer.py

diff --git a/test/functional/mocks/no_signer.py b/test/functional/mocks/no_signer.py
new file mode 100755
index 00000000000..04318dac793
--- /dev/null
+++ b/test/functional/mocks/no_signer.py
@@ -0,0 +1,29 @@
+#!/usr/bin/env python3
+# Copyright (c) 2025-present The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+import argparse
+import json
+import sys
+
+def enumerate(args):
+    sys.stdout.write(json.dumps([]))
+
+parser = argparse.ArgumentParser(prog='./no_signer.py', description='No external signer connected mock')
+
+subparsers = parser.add_subparsers(description='Commands', dest='command')
+subparsers.required = True
+
+parser_enumerate = subparsers.add_parser('enumerate', help='list available signers')
+parser_enumerate.set_defaults(func=enumerate)
+
+
+if not sys.stdin.isatty():
+    buffer = sys.stdin.read()
+    if buffer and buffer.rstrip() != "":
+        sys.argv.extend(buffer.rstrip().split(" "))
+
+args = parser.parse_args()
+
+args.func(args)
diff --git a/test/functional/wallet_signer.py b/test/functional/wallet_signer.py
index c9ac876eb71..208e4c07752 100755
--- a/test/functional/wallet_signer.py
+++ b/test/functional/wallet_signer.py
@@ -23,6 +23,10 @@ class WalletSignerTest(BitcoinTestFramework):
         path = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'mocks', 'signer.py')
         return sys.executable + " " + path
 
+    def mock_no_connected_signer_path(self):
+        path = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'mocks', 'no_signer.py')
+        return sys.executable + " " + path
+
     def mock_invalid_signer_path(self):
         path = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'mocks', 'invalid_signer.py')
         return sys.executable + " " + path
@@ -52,6 +56,7 @@ class WalletSignerTest(BitcoinTestFramework):
 
     def run_test(self):
         self.test_valid_signer()
+        self.test_disconnected_signer()
         self.restart_node(1, [f"-signer={self.mock_invalid_signer_path()}", "-keypool=10"])
         self.test_invalid_signer()
         self.restart_node(1, [f"-signer={self.mock_multi_signers_path()}", "-keypool=10"])
@@ -234,6 +239,28 @@ class WalletSignerTest(BitcoinTestFramework):
         # )
         # self.clear_mock_result(self.nodes[4])
 
+    def test_disconnected_signer(self):
+        self.log.info('Test disconnected external signer')
+
+        # First create a wallet with the signer connected
+        self.nodes[1].createwallet(wallet_name='hww_disconnect', disable_private_keys=True, external_signer=True)
+        hww = self.nodes[1].get_wallet_rpc('hww_disconnect')
+        assert_equal(hww.getwalletinfo()["external_signer"], True)
+
+        # Fund wallet
+        self.nodes[0].sendtoaddress(hww.getnewaddress(address_type="bech32m"), 1)
+        self.generate(self.nodes[0], 1)
+
+        # Restart node with no signer connected
+        self.log.debug(f"-signer={self.mock_no_connected_signer_path()}")
+        self.restart_node(1, [f"-signer={self.mock_no_connected_signer_path()}", "-keypool=10"])
+        self.nodes[1].loadwallet('hww_disconnect')
+        hww = self.nodes[1].get_wallet_rpc('hww_disconnect')
+
+        # Try to spend
+        dest = hww.getrawchangeaddress()
+        assert_raises_rpc_error(-25, "External signer not found", hww.send, outputs=[{dest:0.5}])
+
     def test_invalid_signer(self):
         self.log.debug(f"-signer={self.mock_invalid_signer_path()}")
         self.log.info('Test invalid external signer')