[test] add v0.17.1 wallet upgrade test

Author: Sjors

test/functional/feature_backwards_compatibility.py

@@ -19,6 +19,7 @@
 import shutil
 
 from test_framework.test_framework import BitcoinTestFramework, SkipTest
+from test_framework.descriptors import descsum_create
 
 from test_framework.util import (
     assert_equal,
@@ -240,6 +241,28 @@ def run_test(self):
         self.stop_node(self.num_nodes - 1)
         node_v17.assert_start_raises_init_error(["-wallet=w3_v18"], "Error: Error loading w3_v18: Wallet requires newer version of Bitcoin Core")
         node_v17.assert_start_raises_init_error(["-wallet=w3"], "Error: Error loading w3: Wallet requires newer version of Bitcoin Core")
+        self.start_node(self.num_nodes - 1)
+
+        self.log.info("Test wallet upgrade path...")
+        # u1: regular wallet, created with v0.17
+        node_v17.createwallet(wallet_name="u1_v17")
+        wallet = node_v17.get_wallet_rpc("u1_v17")
+        address = wallet.getnewaddress("bech32")
+        info = wallet.getaddressinfo(address)
+        hdkeypath = info["hdkeypath"]
+        pubkey = info["pubkey"]
+
+        # Copy the wallet to the last Bitcoin Core version and open it:
+        node_v17.unloadwallet("u1_v17")
+        shutil.copytree(
+            os.path.join(node_v17_wallets_dir, "u1_v17"),
+            os.path.join(node_master_wallets_dir, "u1_v17")
+        )
+        node_master.loadwallet("u1_v17")
+        wallet = node_master.get_wallet_rpc("u1_v17")
+        info = wallet.getaddressinfo(address)
+        descriptor = "wpkh([" + info["hdmasterfingerprint"] + hdkeypath[1:] + "]" + pubkey + ")"
+        assert_equal(info["desc"], descsum_create(descriptor))
 
 if __name__ == '__main__':
     BackwardsCompatibilityTest().main()