test: test reorged v3 tx descendants sibling eviction

test/functional/mempool_accept_v3.py

@@ -2,6 +2,7 @@
 # Copyright (c) 2024 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
+from decimal import Decimal
 
 from test_framework.messages import (
     MAX_BIP125_RBF_SEQUENCE,
@@ -187,6 +188,35 @@ def test_v3_reorg(self):
         # This is needed because generate() will create the exact same block again.
         node.reconsiderblock(block[0])
 
+    @cleanup(extra_args=["-acceptnonstdtxn=1"])
+    def test_reorged_v3_tx_descendants_sibling_eviction(self):
+        node = self.nodes[0]
+        self.log.info("Test v3 transaction whose ancestor was reorged can have more than 1 sibling.")
+
+        ancestor_tx = self.wallet.send_self_transfer_multi(from_node=node, num_outputs=3, version=3)
+        self.check_mempool([ancestor_tx["txid"]])
+
+        block = self.generate(node, 1)
+        self.check_mempool([])
+
+        child_1 = self.wallet.send_self_transfer(from_node=node, version=3, utxo_to_spend=ancestor_tx["new_utxos"][0])
+        child_2 = self.wallet.send_self_transfer(from_node=node, version=3, utxo_to_spend=ancestor_tx["new_utxos"][1])
+        self.check_mempool([child_1["txid"], child_2["txid"]])
+
+        self.generate(node, 1)
+        self.check_mempool([])
+
+        node.invalidateblock(block[0])
+        self.check_mempool([ancestor_tx["txid"], child_1["txid"], child_2["txid"]])
+
+        # Increase the fee to create a conflicting transaction for child_1
+        child_1_conflict = self.wallet.send_self_transfer(from_node=node, version=3, utxo_to_spend=ancestor_tx["new_utxos"][0], fee_rate=Decimal("0.01"))
+
+        # Ensure child_1 and child_1_conflict are different transactions
+        assert (child_1_conflict["txid"] != child_1["txid"])
+        self.check_mempool([ancestor_tx["txid"], child_1_conflict["txid"], child_2["txid"]])
+        self.generate(node, 1)
+        self.check_mempool([])
 
     @cleanup(extra_args=["-limitdescendantsize=10", "-datacarriersize=40000", "-acceptnonstdtxn=1"])
     def test_nondefault_package_limits(self):
@@ -412,6 +442,7 @@ def run_test(self):
         self.test_mempool_sibling()
         self.test_v3_package_inheritance()
         self.test_v3_in_testmempoolaccept()
+        self.test_reorged_v3_tx_descendants_sibling_eviction()
 
 
 if __name__ == "__main__":