Adding functional test for MWEB functionality after upgrading non-HD wallet

src/wallet/reserve.cpp

@@ -13,9 +13,11 @@ bool ReserveDestination::GetReservedDestination(CTxDestination& dest, bool inter
         m_spk_man->TopUp();
 
         CKeyPool keypool;
-        if (!m_spk_man->GetReservedDestination(type, internal, address, nIndex, keypool)) {
+        int64_t reserved_index;
+        if (!m_spk_man->GetReservedDestination(type, internal, address, reserved_index, keypool)) {
             return false;
         }
+        nIndex = reserved_index;
         fInternal = keypool.fInternal;
     }
     dest = address;

src/wallet/scriptpubkeyman.cpp

@@ -1441,6 +1441,7 @@ bool LegacyScriptPubKeyMan::ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& key
         bool fReturningInternal = (purpose == KeyPurpose::INTERNAL);
         fReturningInternal &= (IsHDEnabled() && m_storage.CanSupportFeature(FEATURE_HD_SPLIT)) || m_storage.IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS);
         bool fMWEB = (purpose == KeyPurpose::MWEB) && IsHDEnabled() && m_storage.CanSupportFeature(FEATURE_HD_SPLIT);
+        bool use_pre_split = !fMWEB && !set_pre_split_keypool.empty();
 
         auto fn_get_keypool = [this](const bool internal, const bool mweb) -> std::set<int64_t>& {
              if (mweb) {
@@ -1477,7 +1478,7 @@ bool LegacyScriptPubKeyMan::ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& key
             throw std::runtime_error(std::string(__func__) + ": keypool entry misclassified");
         }
         // If the key was pre-split keypool, we don't care about what type it is
-        if (set_pre_split_keypool.empty() && keypool.fInternal != fReturningInternal) {
+        if (!use_pre_split && keypool.fInternal != fReturningInternal) {
             throw std::runtime_error(std::string(__func__) + ": keypool entry misclassified");
         }
         if (!keypool.vchPubKey.IsValid()) {

test/functional/mweb_wallet_upgrade.py

@@ -0,0 +1,97 @@
+#!/usr/bin/env python3
+# Copyright (c) 2021 The Litecoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Tests that non-HD wallets that are upgraded are able to receive via MWEB"""
+
+import os
+import shutil
+
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.ltc_util import create_non_hd_wallet, setup_mweb_chain
+from test_framework.util import assert_equal
+
+class MWEBWalletUpgradeTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.setup_clean_chain = True
+        self.num_nodes = 2
+        self.extra_args = [['-whitelist=noban@127.0.0.1'],[]]  # immediate tx relay
+
+    def skip_test_if_missing_module(self):
+        self.skip_if_no_previous_releases()
+        self.skip_if_no_wallet()
+
+    def run_test(self):
+        node0 = self.nodes[0]
+        node1 = self.nodes[1]
+
+        #
+        # Mine until MWEB is activated
+        #
+        self.log.info("Setting up MWEB chain")
+        setup_mweb_chain(node0)
+        self.sync_all()
+        
+        #
+        # Create a non-HD wallet using an older litecoin core version
+        #
+        self.log.info("Creating non-hd wallet")
+        nonhd_wallet_dat = create_non_hd_wallet(self.chain, self.options)
+
+        #
+        # Replace node1's wallet with the non-HD wallet.dat
+        #
+        #self.log.info("Replacing wallet with non-hd wallet.dat")
+        node1.get_wallet_rpc(self.default_wallet_name).unloadwallet()
+        upgrade_wallet_dir = os.path.join(node1.datadir, "regtest", "wallets", self.default_wallet_name)
+        shutil.rmtree(upgrade_wallet_dir)
+        os.mkdir(upgrade_wallet_dir)
+        shutil.copy(nonhd_wallet_dat, upgrade_wallet_dir)
+        node1.loadwallet(self.default_wallet_name)
+
+        #
+        # Upgrade node1's non-HD wallet to the latest version
+        #
+        self.log.info("Upgrading wallet")
+        node1.upgradewallet()
+        
+        #
+        # Send to MWEB address of upgraded wallet (node1)
+        #
+        self.log.info("Send to upgraded wallet's mweb address")
+        mweb_addr = node1.getnewaddress(address_type='mweb')
+        tx1_id = node0.sendtoaddress(mweb_addr, 25)
+        self.sync_mempools()
+
+        #
+        # Verify transaction is received by upgraded wallet (node1)
+        #
+        self.log.info("Verify upgraded wallet lists the transaction")
+        tx1 = node1.gettransaction(txid=tx1_id)
+        assert_equal(tx1['confirmations'], 0)
+        assert_equal(tx1['amount'], 25)
+        assert_equal(tx1['details'][0]['address'], mweb_addr)
+
+        node0.generate(1)
+        self.sync_all()
+
+        #
+        # Verify that MWEB coins can be spent by upgraded wallet (node1)
+        #
+        self.log.info("Spending MWEB coins")
+        mining_mweb_addr = node0.getnewaddress(address_type='mweb')
+        tx2_id = node1.sendtoaddress(mining_mweb_addr, 10)
+        self.sync_mempools()
+
+        #
+        # Mine 1 block and verify transaction confirms
+        #
+        self.log.info("Mining block to verify it confirms")
+        node0.generate(1)
+        tx2 = node0.gettransaction(txid=tx2_id)
+        assert_equal(tx2['confirmations'], 1)
+        assert_equal(tx2['amount'], 10)
+        assert_equal(tx2['details'][0]['address'], mining_mweb_addr)
+
+if __name__ == '__main__':
+    MWEBWalletUpgradeTest().main()

test/functional/test_framework/ltc_util.py

@@ -4,9 +4,12 @@
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Random assortment of utility functions"""
 
+import os
+
 from test_framework.messages import COIN, COutPoint, CTransaction, CTxIn, CTxOut, MWEBHeader
-from test_framework.util import satoshi_round
+from test_framework.util import get_datadir_path, initialize_datadir, satoshi_round
 from test_framework.script_util import DUMMY_P2WPKH_SCRIPT, hogaddr_script
+from test_framework.test_node import TestNode
 
 """Create a txout with a given amount and scriptPubKey
 
@@ -91,5 +94,43 @@ def create_hogex(node, mweb_hash):
     tx.vout = [CTxOut(int(hog_addr['value'] * COIN), hogaddr_script(mweb_hash))]
     tx.hogex = True
     tx.rehash()
+    return tx
 
-    return tx
+""" Create a non-HD wallet from a temporary v15.1.0 node.
+
+Returns the path of the wallet.dat.
+"""
+def create_non_hd_wallet(chain, options):    
+    version = 150100
+    bin_dir = os.path.join(options.previous_releases_path, 'v0.15.1', 'bin')
+    initialize_datadir(options.tmpdir, 10, chain)
+    data_dir = get_datadir_path(options.tmpdir, 10)
+
+    # adjust conf for pre 17
+    conf_file = os.path.join(data_dir, 'litecoin.conf')
+    with open(conf_file, 'r', encoding='utf8') as conf:
+        conf_data = conf.read()
+    with open(conf_file, 'w', encoding='utf8') as conf:
+        conf.write(conf_data.replace('[regtest]', ''))
+
+    v15_node = TestNode(
+        i=10,
+        datadir=data_dir,
+        chain=chain,
+        rpchost=None,
+        timewait=60,
+        timeout_factor=1.0,
+        bitcoind=os.path.join(bin_dir, 'litecoind'),
+        bitcoin_cli=os.path.join(bin_dir, 'litecoin-cli'),
+        version=version,
+        coverage_dir=None,
+        cwd=options.tmpdir,
+        extra_args=["-usehd=0"],
+    )
+    v15_node.start()
+    v15_node.wait_for_cookie_credentials()  # ensure cookie file is available to avoid race condition
+    v15_node.wait_for_rpc_connection()
+    v15_node.stop_node(wait=0)
+    v15_node.wait_until_stopped()
+    
+    return os.path.join(v15_node.datadir, chain, "wallet.dat")

test/functional/test_runner.py

@@ -252,6 +252,7 @@ BASE_SCRIPTS = [
     'mweb_node_compatibility.py',
     'mweb_wallet_address.py',
     'mweb_wallet_basic.py',
+    'mweb_wallet_upgrade.py',
     'wallet_listwallettransactions.py',
     'rpc_uptime.py',
     'wallet_resendwallettransactions.py',