test: add coverage for unnamed wallet migration failure

furszy · achow101 · commit c95b1121809e · 2026-01-09T10:39:45.000-08:00
Verifies that a failed migration of the unnamed (default) wallet does not erase the main /wallets/ directory, and also that the backup file exists. Github-Pull: #34156 Rebased-From: 36093bd
diff --git a/test/functional/wallet_migration.py b/test/functional/wallet_migration.py
@@ -4,6 +4,7 @@
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Test Migrating a wallet from legacy to descriptor."""
 
+import os
 import random
 import shutil
 import struct
@@ -548,6 +549,39 @@ def test_default_wallet(self):
 
         self.master_node.setmocktime(0)
 
+    def test_default_wallet_failure(self):
+        self.log.info("Test failure during unnamed (default) wallet migration")
+        master_wallet = self.master_node.get_wallet_rpc(self.default_wallet_name)
+        wallet = self.create_legacy_wallet("", blank=True)
+        wallet.importaddress(master_wallet.getnewaddress(address_type="legacy"))
+
+        # Create wallet directory with the watch-only name and a wallet file.
+        # Because the wallet dir exists, this will cause migration to fail.
+        watch_only_dir = self.master_node.wallets_path / "_watchonly"
+        os.mkdir(watch_only_dir)
+        shutil.copyfile(self.old_node.wallets_path / "wallet.dat", watch_only_dir / "wallet.dat")
+
+        mocked_time = int(time.time())
+        self.master_node.setmocktime(mocked_time)
+        assert_raises_rpc_error(-1, "filesystem error: cannot copy file: File exists", self.migrate_and_get_rpc, "")
+        self.master_node.setmocktime(0)
+
+        # Verify the /wallets/ path exists
+        assert self.master_node.wallets_path.exists()
+        # Check backup file exists. Because the wallet has no name, the backup is prefixed with 'default_wallet'
+        backup_path = self.master_node.wallets_path / f"default_wallet_{mocked_time}.legacy.bak"
+        assert backup_path.exists()
+        # Migration will fail to restore the original unnamed wallet
+        # Verify that there is a wallet file
+        assert (self.master_node.wallets_path / "wallet.dat").exists()
+        # And verify it is now a SQLite wallet
+        with open(self.master_node.wallets_path / "wallet.dat", 'rb') as f:
+            file_magic = f.read(16)
+            assert_equal(file_magic, b'SQLite format 3\x00')
+
+        # Test cleanup: clear default wallet for next test
+        os.remove(self.old_node.wallets_path / "wallet.dat")
+
     def test_direct_file(self):
         self.log.info("Test migration of a wallet that is not in a wallet directory")
         wallet = self.create_legacy_wallet("plainfile")
@@ -1372,6 +1406,7 @@ def run_test(self):
         self.test_encrypted()
         self.test_nonexistent()
         self.test_unloaded_by_path()
+        self.test_default_wallet_failure()
         self.test_default_wallet()
         self.test_direct_file()
         self.test_addressbook()
