Merge bitcoin/bitcoin#26448: test: fix intermittent failure in p2p_sendtxrcncl.py

74d975318a1443aebfbcee36e331df4e54ec1fbe test: fix intermittent failure in p2p_sendtxrcncl.py (Martin Zumsande)

Pull request description:

  `p2p_sendtxrcncl.py` currently fails intermittently in the CI, see e.g. https://cirrus-ci.com/task/5511952184115200?logs=ci#L4024

  I believe that this is related to the reuse of the parameter `p2p_idx=2` of `add_outbound_p2p_connection` in this test: When we call `peer_disconnect`, we don't wait until the node has completed the disconnection. So there is a race between setting up the next connection (next  `addconnection` RPC), and if the old one hasn't been removed and has an identical port like the new one (because we didn't increment `p2p_idx`), `CConnman::OpenNetworkConnection` just [returns](https://github.com/bitcoin/bitcoin/blob/5274f324375fd31cf8507531fbc612765d03092f/src/net.cpp#L1976) without establishing a connection, and the test fails.

  Fix this by using distinct `disconnect_p2ps` instead of `peer_disconnect`, which waits for the disconnect to complete. We can then use the same value for `p2p_idx` everywhere.

ACKs for top commit:
  MarcoFalke:
    review ACK 74d975318a1443aebfbcee36e331df4e54ec1fbe

Tree-SHA512: f99f2550b6b320c0a2416a475c1cf189c009fce3a5abf1d4462486e1bfe309e2c3fd4228a4009b0ca38cb77465ce85e3d22298719eb07302fa0a72fbab0e0668

2 files changed, 19 insertions, 15 deletions

diff --git a/test/functional/p2p_sendtxrcncl.py b/test/functional/p2p_sendtxrcncl.py
index 50a5127f25..fed9832a7d 100755
--- a/test/functional/p2p_sendtxrcncl.py
+++ b/test/functional/p2p_sendtxrcncl.py
@@ -74,7 +74,7 @@ class SendTxRcnclTest(BitcoinTestFramework):
         assert not peer.sendtxrcncl_msg_received.initiator
         assert peer.sendtxrcncl_msg_received.responder
         assert_equal(peer.sendtxrcncl_msg_received.version, 1)
-        peer.peer_disconnect()
+        self.nodes[0].disconnect_p2ps()
 
         self.log.info('SENDTXRCNCL should be sent before VERACK')
         peer = self.nodes[0].add_p2p_connection(PeerTrackMsgOrder(), send_version=True, wait_for_verack=True)
@@ -82,7 +82,7 @@ class SendTxRcnclTest(BitcoinTestFramework):
         verack_index = [i for i, msg in enumerate(peer.messages) if msg.msgtype == b'verack'][0]
         sendtxrcncl_index = [i for i, msg in enumerate(peer.messages) if msg.msgtype == b'sendtxrcncl'][0]
         assert(sendtxrcncl_index < verack_index)
-        peer.peer_disconnect()
+        self.nodes[0].disconnect_p2ps()
 
         self.log.info('SENDTXRCNCL on pre-WTXID version should not be sent')
         peer = self.nodes[0].add_p2p_connection(SendTxrcnclReceiver(), send_version=False, wait_for_verack=False)
@@ -94,7 +94,7 @@ class SendTxRcnclTest(BitcoinTestFramework):
         peer.send_message(pre_wtxid_version_msg)
         peer.wait_for_verack()
         assert not peer.sendtxrcncl_msg_received
-        peer.peer_disconnect()
+        self.nodes[0].disconnect_p2ps()
 
         self.log.info('SENDTXRCNCL for fRelay=false should not be sent')
         peer = self.nodes[0].add_p2p_connection(SendTxrcnclReceiver(), send_version=False, wait_for_verack=False)
@@ -106,7 +106,7 @@ class SendTxRcnclTest(BitcoinTestFramework):
         peer.send_message(no_txrelay_version_msg)
         peer.wait_for_verack()
         assert not peer.sendtxrcncl_msg_received
-        peer.peer_disconnect()
+        self.nodes[0].disconnect_p2ps()
 
         self.log.info('valid SENDTXRCNCL received')
         peer = self.nodes[0].add_p2p_connection(PeerNoVerack(), send_version=True, wait_for_verack=False)
@@ -152,31 +152,31 @@ class SendTxRcnclTest(BitcoinTestFramework):
         with self.nodes[0].assert_debug_log(['Forget txreconciliation state of peer']):
             peer.send_message(create_sendtxrcncl_msg())
             peer.send_message(msg_verack())
-        peer.peer_disconnect()
+        self.nodes[0].disconnect_p2ps()
 
         self.log.info('SENDTXRCNCL sent to an outbound')
         peer = self.nodes[0].add_outbound_p2p_connection(
-            SendTxrcnclReceiver(), wait_for_verack=True, p2p_idx=1, connection_type="outbound-full-relay")
+            SendTxrcnclReceiver(), wait_for_verack=True, p2p_idx=0, connection_type="outbound-full-relay")
         assert peer.sendtxrcncl_msg_received
         assert peer.sendtxrcncl_msg_received.initiator
         assert not peer.sendtxrcncl_msg_received.responder
         assert_equal(peer.sendtxrcncl_msg_received.version, 1)
-        peer.peer_disconnect()
+        self.nodes[0].disconnect_p2ps()
 
         self.log.info('SENDTXRCNCL should not be sent if block-relay-only')
         peer = self.nodes[0].add_outbound_p2p_connection(
-            SendTxrcnclReceiver(), wait_for_verack=True, p2p_idx=2, connection_type="block-relay-only")
+            SendTxrcnclReceiver(), wait_for_verack=True, p2p_idx=0, connection_type="block-relay-only")
         assert not peer.sendtxrcncl_msg_received
-        peer.peer_disconnect()
+        self.nodes[0].disconnect_p2ps()
 
         self.log.info("SENDTXRCNCL should not be sent if feeler")
-        peer = self.nodes[0].add_outbound_p2p_connection(P2PFeelerReceiver(), p2p_idx=2, connection_type="feeler")
+        peer = self.nodes[0].add_outbound_p2p_connection(P2PFeelerReceiver(), p2p_idx=0, connection_type="feeler")
         assert not peer.sendtxrcncl_msg_received
-        peer.peer_disconnect()
+        self.nodes[0].disconnect_p2ps()
 
         self.log.info('SENDTXRCNCL if block-relay-only triggers a disconnect')
         peer = self.nodes[0].add_outbound_p2p_connection(
-            PeerNoVerack(), wait_for_verack=False, p2p_idx=3, connection_type="block-relay-only")
+            PeerNoVerack(), wait_for_verack=False, p2p_idx=0, connection_type="block-relay-only")
         with self.nodes[0].assert_debug_log(["we indicated no tx relay; disconnecting"]):
             peer.send_message(create_sendtxrcncl_msg(initiator=False))
             peer.wait_for_disconnect()
@@ -184,7 +184,7 @@ class SendTxRcnclTest(BitcoinTestFramework):
         self.log.info('SENDTXRCNCL with initiator=1 and responder=0 from outbound triggers a disconnect')
         sendtxrcncl_wrong_role = create_sendtxrcncl_msg(initiator=True)
         peer = self.nodes[0].add_outbound_p2p_connection(
-            PeerNoVerack(), wait_for_verack=False, p2p_idx=4, connection_type="outbound-full-relay")
+            PeerNoVerack(), wait_for_verack=False, p2p_idx=0, connection_type="outbound-full-relay")
         with self.nodes[0].assert_debug_log(["txreconciliation protocol violation"]):
             peer.send_message(sendtxrcncl_wrong_role)
             peer.wait_for_disconnect()
@@ -193,13 +193,13 @@ class SendTxRcnclTest(BitcoinTestFramework):
         self.restart_node(0, [])
         peer = self.nodes[0].add_p2p_connection(SendTxrcnclReceiver(), send_version=True, wait_for_verack=True)
         assert not peer.sendtxrcncl_msg_received
-        peer.peer_disconnect()
+        self.nodes[0].disconnect_p2ps()
 
         self.log.info('SENDTXRCNCL not sent if blocksonly is set')
         self.restart_node(0, ["-txreconciliation", "-blocksonly"])
         peer = self.nodes[0].add_p2p_connection(SendTxrcnclReceiver(), send_version=True, wait_for_verack=True)
         assert not peer.sendtxrcncl_msg_received
-        peer.peer_disconnect()
+        self.nodes[0].disconnect_p2ps()
 
 
 if __name__ == '__main__':
diff --git a/test/functional/test_framework/test_node.py b/test/functional/test_framework/test_node.py
index 83f9f253fd..0075fa0996 100755
--- a/test/functional/test_framework/test_node.py
+++ b/test/functional/test_framework/test_node.py
@@ -625,6 +625,10 @@ class TestNode():
 
         This method adds the p2p connection to the self.p2ps list and returns
         the connection to the caller.
+
+        p2p_idx must be different for simultaneously connected peers. When reusing it for the next peer
+        after disconnecting the previous one, it is necessary to wait for the disconnect to finish to avoid
+        a race condition.
         """
 
         def addconnection_callback(address, port):