For feebump, ignore abandoned descendant spends

To be eligible for fee-bumping, a transaction must not have any
of its outputs (eg - change) spent in other unconfirmed transactions
in the wallet. However, this check should not apply to abandoned
transactions.

A new test case is added to cover this case.

Author: john-moffett

src/wallet/wallet.cpp

@@ -648,8 +648,7 @@ bool CWallet::HasWalletSpend(const CTransactionRef& tx) const
     AssertLockHeld(cs_wallet);
     const uint256& txid = tx->GetHash();
     for (unsigned int i = 0; i < tx->vout.size(); ++i) {
-        auto iter = mapTxSpends.find(COutPoint(txid, i));
-        if (iter != mapTxSpends.end()) {
+        if (IsSpent(COutPoint(txid, i))) {
             return true;
         }
     }

test/functional/wallet_bumpfee.py

@@ -88,6 +88,7 @@ def run_test(self):
         test_nonrbf_bumpfee_fails(self, peer_node, dest_address)
         test_notmine_bumpfee(self, rbf_node, peer_node, dest_address)
         test_bumpfee_with_descendant_fails(self, rbf_node, rbf_node_address, dest_address)
+        test_bumpfee_with_abandoned_descendant_succeeds(self, rbf_node, rbf_node_address, dest_address)
         test_dust_to_fee(self, rbf_node, dest_address)
         test_watchonly_psbt(self, peer_node, rbf_node, dest_address)
         test_rebumping(self, rbf_node, dest_address)
@@ -286,6 +287,35 @@ def test_bumpfee_with_descendant_fails(self, rbf_node, rbf_node_address, dest_ad
     self.clear_mempool()
 
 
+def test_bumpfee_with_abandoned_descendant_succeeds(self, rbf_node, rbf_node_address, dest_address):
+    self.log.info('Test that fee can be bumped when it has abandoned descendant')
+    # parent is send-to-self, so we don't have to check which output is change when creating the child tx
+    parent_id = spend_one_input(rbf_node, rbf_node_address)
+    # Submit child transaction with low fee
+    child_id = rbf_node.send(outputs={dest_address: 0.00020000},
+                             options={"inputs": [{"txid": parent_id, "vout": 0}], "fee_rate": 2})["txid"]
+    assert child_id in rbf_node.getrawmempool()
+
+    # Restart the node with higher min relay fee so the descendant tx is no longer in mempool so that we can abandon it
+    self.restart_node(1, ['-minrelaytxfee=0.00005'] + self.extra_args[1])
+    rbf_node.walletpassphrase(WALLET_PASSPHRASE, WALLET_PASSPHRASE_TIMEOUT)
+    self.connect_nodes(1, 0)
+    assert parent_id in rbf_node.getrawmempool()
+    assert child_id not in rbf_node.getrawmempool()
+    # Should still raise an error even if not in mempool
+    assert_raises_rpc_error(-8, "Transaction has descendants in the wallet", rbf_node.bumpfee, parent_id)
+    # Now abandon the child transaction and bump the original
+    rbf_node.abandontransaction(child_id)
+    bumped_result = rbf_node.bumpfee(parent_id, {"fee_rate": HIGH})
+    assert bumped_result['txid'] in rbf_node.getrawmempool()
+    assert parent_id not in rbf_node.getrawmempool()
+    # Cleanup
+    self.restart_node(1, self.extra_args[1])
+    rbf_node.walletpassphrase(WALLET_PASSPHRASE, WALLET_PASSPHRASE_TIMEOUT)
+    self.connect_nodes(1, 0)
+    self.clear_mempool()
+
+
 def test_small_output_with_feerate_succeeds(self, rbf_node, dest_address):
     self.log.info('Testing small output with feerate bump succeeds')