Merge #13003: qa: Add test for orphan handling

fa02c5b qa: Clarify documentation for send_txs_and_test (MarcoFalke)
fadfbd3 qa: Add test for orphan handling (MarcoFalke)

Pull request description:

Tree-SHA512: e0932d6bd03c73e3113f5457a3ffa3bbfc7b6075dfca8de95224d9df875e60ca6eb15cd8baa226f13de965483006559556191630a83c3bb431e79c53a85ef73f

3 files changed, 116 insertions, 26 deletions

diff --git a/test/functional/feature_block.py b/test/functional/feature_block.py
index 38b76239e5..17d3ddae4a 100755
--- a/test/functional/feature_block.py
+++ b/test/functional/feature_block.py
@@ -82,10 +82,7 @@ class FullBlockTest(BitcoinTestFramework):
     def run_test(self):
         node = self.nodes[0]  # convenience reference to the node
 
-        # reconnect_p2p() expects the network thread to be running
-        network_thread_start()
-
-        self.reconnect_p2p()
+        self.bootstrap_p2p()  # Add one p2p connection to the node
 
         self.block_heights = {}
         self.coinbase_key = CECKey()
@@ -1296,14 +1293,10 @@ class FullBlockTest(BitcoinTestFramework):
         self.blocks[block_number] = block
         return block
 
-    def reconnect_p2p(self):
+    def bootstrap_p2p(self):
         """Add a P2P connection to the node.
 
-        The node gets disconnected several times in this test. This helper
-        method reconnects the p2p and restarts the network thread."""
-
-        network_thread_join()
-        self.nodes[0].disconnect_p2ps()
+        Helper to connect and wait for version handshake."""
         self.nodes[0].add_p2p_connection(P2PDataStore())
         network_thread_start()
         # We need to wait for the initial getheaders from the peer before we
@@ -1314,6 +1307,15 @@ class FullBlockTest(BitcoinTestFramework):
         # unexpectedly disconnected if the DoS score for that error is 50.
         self.nodes[0].p2p.wait_for_getheaders(timeout=5)
 
+    def reconnect_p2p(self):
+        """Tear down and bootstrap the P2P connection to the node.
+
+        The node gets disconnected several times in this test. This helper
+        method reconnects the p2p and restarts the network thread."""
+        self.nodes[0].disconnect_p2ps()
+        network_thread_join()
+        self.bootstrap_p2p()
+
     def sync_blocks(self, blocks, success=True, reject_code=None, reject_reason=None, request_block=True, reconnect=False, timeout=60):
         """Sends blocks to test node. Syncs and verifies that tip has advanced to most recent block.
 
diff --git a/test/functional/p2p_invalid_tx.py b/test/functional/p2p_invalid_tx.py
index 69ce529ad6..8a0961be1f 100755
--- a/test/functional/p2p_invalid_tx.py
+++ b/test/functional/p2p_invalid_tx.py
@@ -6,24 +6,48 @@
 
 In this test we connect to one node over p2p, and test tx requests."""
 from test_framework.blocktools import create_block, create_coinbase, create_transaction
-from test_framework.messages import COIN
-from test_framework.mininode import network_thread_start, P2PDataStore
+from test_framework.messages import (
+    COIN,
+    COutPoint,
+    CTransaction,
+    CTxIn,
+    CTxOut,
+)
+from test_framework.mininode import network_thread_start, P2PDataStore, network_thread_join
 from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import (
+    assert_equal,
+    wait_until,
+)
 
-class InvalidTxRequestTest(BitcoinTestFramework):
 
+class InvalidTxRequestTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 1
         self.setup_clean_chain = True
-        self.extra_args = [["-whitelist=127.0.0.1"]]
+
+    def bootstrap_p2p(self, *, num_connections=1):
+        """Add a P2P connection to the node.
+
+        Helper to connect and wait for version handshake."""
+        for _ in range(num_connections):
+            self.nodes[0].add_p2p_connection(P2PDataStore())
+        network_thread_start()
+        self.nodes[0].p2p.wait_for_verack()
+
+    def reconnect_p2p(self, **kwargs):
+        """Tear down and bootstrap the P2P connection to the node.
+
+        The node gets disconnected several times in this test. This helper
+        method reconnects the p2p and restarts the network thread."""
+        self.nodes[0].disconnect_p2ps()
+        network_thread_join()
+        self.bootstrap_p2p(**kwargs)
 
     def run_test(self):
-        # Add p2p connection to node0
         node = self.nodes[0]  # convenience reference to the node
-        node.add_p2p_connection(P2PDataStore())
 
-        network_thread_start()
-        node.p2p.wait_for_verack()
+        self.bootstrap_p2p()  # Add one p2p connection to the node
 
         best_block = self.nodes[0].getbestblockhash()
         tip = int(best_block, 16)
@@ -44,12 +68,73 @@ class InvalidTxRequestTest(BitcoinTestFramework):
 
         # b'\x64' is OP_NOTIF
         # Transaction will be rejected with code 16 (REJECT_INVALID)
+        # and we get disconnected immediately
+        self.log.info('Test a transaction that is rejected')
         tx1 = create_transaction(block1.vtx[0], 0, b'\x64', 50 * COIN - 12000)
-        node.p2p.send_txs_and_test([tx1], node, success=False, reject_code=16, reject_reason=b'mandatory-script-verify-flag-failed (Invalid OP_IF construction)')
+        node.p2p.send_txs_and_test([tx1], node, success=False, expect_disconnect=True)
+
+        # Make two p2p connections to provide the node with orphans
+        # * p2ps[0] will send valid orphan txs (one with low fee)
+        # * p2ps[1] will send an invalid orphan tx (and is later disconnected for that)
+        self.reconnect_p2p(num_connections=2)
+
+        self.log.info('Test orphan transaction handling ... ')
+        # Create a root transaction that we withold until all dependend transactions
+        # are sent out and in the orphan cache
+        tx_withhold = CTransaction()
+        tx_withhold.vin.append(CTxIn(outpoint=COutPoint(block1.vtx[0].sha256, 0)))
+        tx_withhold.vout.append(CTxOut(nValue=50 * COIN - 12000, scriptPubKey=b'\x51'))
+        tx_withhold.calc_sha256()
+
+        # Our first orphan tx with some outputs to create further orphan txs
+        tx_orphan_1 = CTransaction()
+        tx_orphan_1.vin.append(CTxIn(outpoint=COutPoint(tx_withhold.sha256, 0)))
+        tx_orphan_1.vout = [CTxOut(nValue=10 * COIN, scriptPubKey=b'\x51')] * 3
+        tx_orphan_1.calc_sha256()
+
+        # A valid transaction with low fee
+        tx_orphan_2_no_fee = CTransaction()
+        tx_orphan_2_no_fee.vin.append(CTxIn(outpoint=COutPoint(tx_orphan_1.sha256, 0)))
+        tx_orphan_2_no_fee.vout.append(CTxOut(nValue=10 * COIN, scriptPubKey=b'\x51'))
+
+        # A valid transaction with sufficient fee
+        tx_orphan_2_valid = CTransaction()
+        tx_orphan_2_valid.vin.append(CTxIn(outpoint=COutPoint(tx_orphan_1.sha256, 1)))
+        tx_orphan_2_valid.vout.append(CTxOut(nValue=10 * COIN - 12000, scriptPubKey=b'\x51'))
+        tx_orphan_2_valid.calc_sha256()
+
+        # An invalid transaction with negative fee
+        tx_orphan_2_invalid = CTransaction()
+        tx_orphan_2_invalid.vin.append(CTxIn(outpoint=COutPoint(tx_orphan_1.sha256, 2)))
+        tx_orphan_2_invalid.vout.append(CTxOut(nValue=11 * COIN, scriptPubKey=b'\x51'))
+
+        self.log.info('Send the orphans ... ')
+        # Send valid orphan txs from p2ps[0]
+        node.p2p.send_txs_and_test([tx_orphan_1, tx_orphan_2_no_fee, tx_orphan_2_valid], node, success=False)
+        # Send invalid tx from p2ps[1]
+        node.p2ps[1].send_txs_and_test([tx_orphan_2_invalid], node, success=False)
+
+        assert_equal(0, node.getmempoolinfo()['size'])  # Mempool should be empty
+        assert_equal(2, len(node.getpeerinfo()))  # p2ps[1] is still connected
+
+        self.log.info('Send the withhold tx ... ')
+        node.p2p.send_txs_and_test([tx_withhold], node, success=True)
+
+        # Transactions that should end up in the mempool
+        expected_mempool = {
+            t.hash
+            for t in [
+                tx_withhold,  # The transaction that is the root for all orphans
+                tx_orphan_1,  # The orphan transaction that splits the coins
+                tx_orphan_2_valid,  # The valid transaction (with sufficient fee)
+            ]
+        }
+        # Transactions that do not end up in the mempool
+        # tx_orphan_no_fee, because it has too low fee (p2ps[0] is not disconnected for relaying that tx)
+        # tx_orphan_invaid, because it has negative fee (p2ps[1] is disconnected for relaying that tx)
 
-        # Verify valid transaction
-        tx1 = create_transaction(block1.vtx[0], 0, b'', 50 * COIN - 12000)
-        node.p2p.send_txs_and_test([tx1], node, success=True)
+        wait_until(lambda: 1 == len(node.getpeerinfo()), timeout=12)  # p2ps[1] is no longer connected
+        assert_equal(expected_mempool, set(node.getrawmempool()))
 
 
 if __name__ == '__main__':
diff --git a/test/functional/test_framework/mininode.py b/test/functional/test_framework/mininode.py
index aba2841682..7c2125a177 100755
--- a/test/functional/test_framework/mininode.py
+++ b/test/functional/test_framework/mininode.py
@@ -554,13 +554,13 @@ class P2PDataStore(P2PInterface):
         if reject_reason is not None:
             wait_until(lambda: self.reject_reason_received == reject_reason, lock=mininode_lock)
 
-    def send_txs_and_test(self, txs, rpc, success=True, reject_code=None, reject_reason=None):
+    def send_txs_and_test(self, txs, rpc, success=True, expect_disconnect=False, reject_code=None, reject_reason=None):
         """Send txs to test node and test whether they're accepted to the mempool.
 
          - add all txs to our tx_store
          - send tx messages for all txs
-         - if success is True: assert that the tx is accepted to the mempool
-         - if success is False: assert that the tx is not accepted to the mempool
+         - if success is True/False: assert that the txs are/are not accepted to the mempool
+         - if expect_disconnect is True: Skip the sync with ping
          - if reject_code and reject_reason are set: assert that the correct reject message is received."""
 
         with mininode_lock:
@@ -573,7 +573,10 @@ class P2PDataStore(P2PInterface):
         for tx in txs:
             self.send_message(msg_tx(tx))
 
-        self.sync_with_ping()
+        if expect_disconnect:
+            self.wait_for_disconnect()
+        else:
+            self.sync_with_ping()
 
         raw_mempool = rpc.getrawmempool()
         if success: