Repository: bitcoin/bitcoin
File: test/functional/wallet_reorgsrestore.py (Python)

Code before:
        self.disconnect_nodes(1, 2)
        self.connect_nodes(0, 2)

        # Send a tx to be unconfirmed later
        txid = self.nodes[0].sendtoaddress(self.nodes[0].getnewaddress(), Decimal("10"))
        tx = self.nodes[0].gettransaction(txid)
        self.generate(self.nodes[0], 4, sync_fun=self.no_op)
        self.sync_blocks([self.nodes[0], self.nodes[2]])
        tx_before_reorg = self.nodes[0].gettransaction(txid)
        assert_equal(tx_before_reorg["confirmations"], 4)

        # Disconnect node0 from node2 to broadcast a conflict on their respective chains
        self.disconnect_nodes(0, 2)
        nA = next(tx_out["vout"] for tx_out in self.nodes[0].gettransaction(txid_conflict_from)["details"] if tx_out["amount"] == Decimal("10"))
        inputs = []
        inputs.append({"txid": txid_conflict_from, "vout": nA})
        outputs_1 = {}
        outputs_2 = {}

        # Create a conflicted tx broadcast on node0 chain and conflicting tx broadcast on node1 chain. Both spend from txid_conflict_from
        outputs_1[self.nodes[0].getnewaddress()] = Decimal("9.99998")
        outputs_2[self.nodes[0].getnewaddress()] = Decimal("9.99998")
        conflicted = self.nodes[0].signrawtransactionwithwallet(self.nodes[0].createrawtransaction(inputs, outputs_1))
        conflicting = self.nodes[0].signrawtransactionwithwallet(self.nodes[0].createrawtransaction(inputs, outputs_2))

        conflicted_txid = self.nodes[0].sendrawtransaction(conflicted["hex"])
        self.generate(self.nodes[0], 1, sync_fun=self.no_op)
        conflicting_txid = self.nodes[2].sendrawtransaction(conflicting["hex"])
        self.generate(self.nodes[2], 9, sync_fun=self.no_op)

        # Reconnect node0 and node2 and check that conflicted_txid is effectively conflicted
        self.connect_nodes(0, 2)
        self.sync_blocks([self.nodes[0], self.nodes[2]])
        conflicted = self.nodes[0].gettransaction(conflicted_txid)
        conflicting = self.nodes[0].gettransaction(conflicting_txid)
        assert_equal(conflicted["confirmations"], -9)
        assert_equal(conflicted["walletconflicts"][0], conflicting["txid"])

        # Node0 wallet is shutdown
        self.restart_node(0)

        # The block chain re-orgs and the tx is included in a different block
        self.generate(self.nodes[1], 9, sync_fun=self.no_op)
        self.nodes[1].sendrawtransaction(tx["hex"])
        self.generate(self.nodes[1], 1, sync_fun=self.no_op)
        self.nodes[1].sendrawtransaction(conflicted["hex"])
        self.generate(self.nodes[1], 1, sync_fun=self.no_op)

        # Node0 wallet file is loaded on longest sync'ed node1
        self.stop_node(1)
        self.nodes[0].backupwallet(self.nodes[0].datadir_path / 'wallet.bak')

Review comment (bug):
>  This issue blocks any future spending and results in an incorrect balance display.

Technically correct but since the block was supposed to be invalidated and with the assumption that the likelihood for it to be invalidated again (successfully this time) is high, this immature unspent will not be blocked for long.

Not suggesting any changes, just noteworthy. Please do LMK if my assumption is incorrect.

Code after:

        # Restart to ensure node and wallet are flushed
        self.restart_node(0)
        wallet = node.get_wallet_rpc("reorg_crash")
        assert_greater_than(wallet.getwalletinfo()['immature_balance'], 0)

        # Disconnect tip and sync wallet state
        tip = wallet.getbestblockhash()
        wallet.invalidateblock(tip)
        wallet.syncwithvalidationinterfacequeue()

        # Tip was disconnected, ensure coinbase has been abandoned
        assert_equal(wallet.getwalletinfo()['immature_balance'], 0)
        coinbase_tx_id = wallet.getblock(tip, verbose=1)["tx"][0]
        assert_equal(wallet.gettransaction(coinbase_tx_id)['details'][0]['abandoned'], True)

        # Abort process abruptly to mimic an unclean shutdown (no chain state flush to disk)
        node.process.kill()

        # Restart the node and confirm that it has not persisted the last chain state changes to disk
        self.start_node(0)
        assert_equal(node.getbestblockhash(), tip)

        # Due to an existing bug, the wallet incorrectly keeps the transaction in an abandoned state, even though that's
        # no longer the case (after the unclean shutdown, the node's chain returned to the pre-invalidation tip).
        # This issue blocks any future spending and results in an incorrect balance display.
        wallet = node.get_wallet_rpc("reorg_crash")
        assert_equal(wallet.getwalletinfo()['immature_balance'], 0) # FIXME: #31824.

        # Previously, a bug caused the node to crash if two block disconnection events occurred consecutively.
        # Ensure this is no longer the case by simulating a new reorg.
        node.invalidateblock(tip)
        assert(node.getbestblockhash() != tip)
        # Ensure wallet state is consistent now
        assert_equal(wallet.gettransaction(coinbase_tx_id)['details'][0]['abandoned'], True)
        assert_equal(wallet.getwalletinfo()['immature_balance'], 0)

        # And finally, verify the state if the block ends up being into the best chain again
        node.reconsiderblock(tip)
        assert_equal(wallet.gettransaction(coinbase_tx_id)['details'][0]['abandoned'], False)
        assert_greater_than(wallet.getwalletinfo()['immature_balance'], 0)

    def run_test(self):
        # Send a tx from which to conflict outputs later
        txid_conflict_from = self.nodes[0].sendtoaddress(self.nodes[0].getnewaddress(), Decimal("10"))
        self.generate(self.nodes[0], 1)

        # Disconnect node1 from others to reorg its chain later
        self.disconnect_nodes(0, 1)
        self.disconnect_nodes(1, 2)
        self.connect_nodes(0, 2)