test: let connections happen in any order in p2p_private_broadcast.py

diff --git a/test/functional/p2p_private_broadcast.py b/test/functional/p2p_private_broadcast.py
index 803444cc..07c6dc97 100755
--- a/test/functional/p2p_private_broadcast.py
+++ b/test/functional/p2p_private_broadcast.py
@@ -6,6 +6,7 @@
 Test how locally submitted transactions are sent to the network when private broadcast is used.
 """
 
+import re
 import time
 import threading
 
@@ -46,9 +47,6 @@ from test_framework.wallet import (
     MiniWallet,
 )
 
-MAX_OUTBOUND_FULL_RELAY_CONNECTIONS = 8
-MAX_BLOCK_RELAY_ONLY_CONNECTIONS = 2
-NUM_INITIAL_CONNECTIONS = MAX_OUTBOUND_FULL_RELAY_CONNECTIONS + MAX_BLOCK_RELAY_ONLY_CONNECTIONS
 NUM_PRIVATE_BROADCAST_PER_TX = 3
 
 # Fill addrman with these addresses. Must have enough Tor addresses, so that even
@@ -184,24 +182,56 @@ class P2PPrivateBroadcast(BitcoinTestFramework):
 
         self.destinations_lock = threading.Lock()
 
+        def find_connection_type_in_debug_log(to_addr, to_port):
+            """
+            Scan the debug log of tx_originator for a connection attempt to to_addr:to_port.
+            Return the connection type (outbound-full-relay, private-broadcast, etc) or
+            None if there is no connection attempt to to_addr:to_port.
+            """
+            with open(self.tx_originator_debug_log_path, mode="r", encoding="utf-8") as debug_log:
+                for line in debug_log.readlines():
+                    match = re.match(f".*trying v. connection \\((.+)\\) to \\[?{to_addr}]?:{to_port},.*", line)
+                    if match:
+                        return match.group(1)
+            return None
+
         def destinations_factory(requested_to_addr, requested_to_port):
+            """
+            Instruct the SOCKS5 proxy to redirect connections:
+            * The first automatic outbound connection -> P2PDataStore
+            * The first private broadcast connection -> nodes[1]
+            * Anything else -> P2PInterface
+            """
+            conn_type = None
+            def found_connection_in_debug_log():
+                nonlocal conn_type
+                conn_type = find_connection_type_in_debug_log(requested_to_addr, requested_to_port)
+                return conn_type is not None
+
+            self.wait_until(found_connection_in_debug_log)
+
             with self.destinations_lock:
                 i = len(self.destinations)
                 actual_to_addr = ""
                 actual_to_port = 0
                 listener = None
-                if i == NUM_INITIAL_CONNECTIONS:
+                target_name = ""
+                if conn_type == "private-broadcast" and not any(dest["conn_type"] == "private-broadcast" for dest in self.destinations):
                     # Instruct the SOCKS5 server to redirect the first private
                     # broadcast connection from nodes[0] to nodes[1]
                     actual_to_addr = "127.0.0.1" # nodes[1] listen address
                     actual_to_port = tor_port(1) # nodes[1] listen port for Tor
-                    self.log.debug(f"Instructing the SOCKS5 proxy to redirect connection i={i} to "
-                                   f"{format_addr_port(actual_to_addr, actual_to_port)} (nodes[1])")
+                    target_name = "nodes[1]"
                 else:
                     # Create a Python P2P listening node and instruct the SOCKS5 proxy to
                     # redirect the connection to it. The first outbound connection is used
                     # later to serve GETDATA, thus make it P2PDataStore().
-                    listener = P2PDataStore() if i == 0 else P2PInterface()
+                    if conn_type == "outbound-full-relay" and not any(dest["conn_type"] == "outbound-full-relay" for dest in self.destinations):
+                        listener = P2PDataStore()
+                        target_name = "Python P2PDataStore"
+                    else:
+                        listener = P2PInterface()
+                        target_name = "Python P2PInterface"
                     listener.peer_connect_helper(dstaddr="0.0.0.0", dstport=0, net=self.chain, timeout_factor=self.options.timeout_factor)
                     listener.peer_connect_send_version(services=P2P_SERVICES)
 
@@ -221,11 +251,14 @@ class P2PPrivateBroadcast(BitcoinTestFramework):
                         callback=on_listen_done)
                     # Wait until the callback has been called.
                     self.wait_until(lambda: actual_to_port != 0)
-                    self.log.debug(f"Instructing the SOCKS5 proxy to redirect connection i={i} to "
-                                   f"{format_addr_port(actual_to_addr, actual_to_port)} (a Python node)")
+
+                self.log.debug(f"Instructing the SOCKS5 proxy to redirect connection i={i} ({conn_type}) for "
+                               f"{format_addr_port(requested_to_addr, requested_to_port)} to "
+                               f"{format_addr_port(actual_to_addr, actual_to_port)} ({target_name})")
 
                 self.destinations.append({
                     "requested_to": format_addr_port(requested_to_addr, requested_to_port),
+                    "conn_type": conn_type,
                     "node": listener,
                 })
                 assert_equal(len(self.destinations), i + 1)
@@ -263,6 +296,15 @@ class P2PPrivateBroadcast(BitcoinTestFramework):
         self.setup_nodes()
 
     def check_broadcasts(self, label, tx, broadcasts_to_expect, skip_destinations):
+        def wait_and_get_destination(n):
+            """Wait for self.destinations[] to have at least n elements and return the 'n'th."""
+            def get_destinations_len():
+                with self.destinations_lock:
+                    return len(self.destinations)
+            self.wait_until(lambda: get_destinations_len() > n)
+            with self.destinations_lock:
+                return self.destinations[n]
+
         broadcasts_done = 0
         i = skip_destinations - 1
         while broadcasts_done < broadcasts_to_expect:
@@ -270,9 +312,10 @@ class P2PPrivateBroadcast(BitcoinTestFramework):
             self.log.debug(f"{label}: waiting for outbound connection i={i}")
             # At this point the connection may not yet have been established (A),
             # may be active (B), or may have already been closed (C).
-            self.wait_until(lambda: len(self.destinations) > i)
-            dest = self.destinations[i]
+            dest = wait_and_get_destination(i)
             peer = dest["node"]
+            if peer is None:
+                continue # That is the first private broadcast connection, redirected to nodes[1]
             peer.wait_until(lambda: peer.message_count["version"] == 1, check_connected=False)
             # Now it is either (B) or (C).
             if peer.last_message["version"].nServices != 0:
@@ -304,6 +347,7 @@ class P2PPrivateBroadcast(BitcoinTestFramework):
 
     def run_test(self):
         tx_originator = self.nodes[0]
+        self.tx_originator_debug_log_path = tx_originator.debug_log_path
         tx_receiver = self.nodes[1]
         far_observer = tx_receiver.add_p2p_connection(P2PInterface())
 
@@ -315,26 +359,20 @@ class P2PPrivateBroadcast(BitcoinTestFramework):
             if not res["success"]:
                 self.log.debug(f"Could not add {addr} to tx_originator's addrman (collision?)")
 
-        self.wait_until(lambda: len(self.destinations) == NUM_INITIAL_CONNECTIONS)
-
-        # The next opened connection by tx_originator should be "private broadcast"
-        # for sending the transaction. The SOCKS5 proxy should redirect it to tx_receiver.
-
         txs = wallet.create_self_transfer_chain(chain_length=3)
         self.log.info(f"Created txid={txs[0]['txid']}: for basic test")
         self.log.info(f"Created txid={txs[1]['txid']}: for broadcast with dependency in mempool + rebroadcast")
         self.log.info(f"Created txid={txs[2]['txid']}: for broadcast with dependency not in mempool")
         tx_originator.sendrawtransaction(hexstring=txs[0]["hex"], maxfeerate=0.1)
 
-        self.log.debug(f"Waiting for outbound connection i={NUM_INITIAL_CONNECTIONS}, "
-                       "must be the first private broadcast connection")
+        self.log.info("First private broadcast: waiting for the transaction to reach the recipient")
         self.wait_until(lambda: len(tx_receiver.getrawmempool()) > 0)
+        self.log.info("First private broadcast: the recipient received the transaction")
         far_observer.wait_for_tx(txs[0]["txid"])
-        self.log.info(f"Outbound connection i={NUM_INITIAL_CONNECTIONS}: "
-                      "the private broadcast target received and further relayed the transaction")
+        self.log.info("First private broadcast: the recipient further relayed the transaction")
 
         # One already checked above, check the other NUM_PRIVATE_BROADCAST_PER_TX - 1 broadcasts.
-        self.check_broadcasts("Basic", txs[0], NUM_PRIVATE_BROADCAST_PER_TX - 1, NUM_INITIAL_CONNECTIONS + 1)
+        self.check_broadcasts("Basic", txs[0], NUM_PRIVATE_BROADCAST_PER_TX - 1, 0)
 
         self.log.info("Resending the same transaction via RPC again (it is not in the mempool yet)")
         ignoring_msg = f"Ignoring unnecessary request to schedule an already scheduled transaction: txid={txs[0]['txid']}, wtxid={txs[0]['wtxid']}"
@@ -354,8 +392,32 @@ class P2PPrivateBroadcast(BitcoinTestFramework):
         wtxid_int = int(txs[0]["wtxid"], 16)
         inv = CInv(MSG_WTX, wtxid_int)
 
+        tx_returner = None # First outbound-full-relay, will be P2PDataStore.
+        other_peer = None # Any other outbound-full-relay, we use the second one.
+
+        def set_tx_returner_and_other():
+            nonlocal tx_returner
+            nonlocal other_peer
+            tx_returner = None
+            other_peer = None
+            with self.destinations_lock:
+                for dest in self.destinations:
+                    if dest["conn_type"] == "outbound-full-relay" and dest["node"] is not None:
+                        if tx_returner is None:
+                            assert(type(dest["node"]) is P2PDataStore)
+                            tx_returner = dest["node"]
+                        else:
+                            assert(type(dest["node"]) is P2PInterface)
+                            other_peer = dest["node"]
+                            return True
+            return False
+
+        self.wait_until(set_tx_returner_and_other)
+
+        tx_returner.wait_for_connect()
+        other_peer.wait_for_connect()
+
         self.log.info("Sending INV and waiting for GETDATA from node")
-        tx_returner = self.destinations[0]["node"] # Will return the transaction back to the originator.
         tx_returner.tx_store[wtxid_int] = txs[0]["tx"]
         assert "getdata" not in tx_returner.last_message
         received_back_msg = f"Received our privately broadcast transaction (txid={txs[0]['txid']}) from the network"
@@ -365,7 +427,7 @@ class P2PPrivateBroadcast(BitcoinTestFramework):
             self.wait_until(lambda: len(tx_originator.getrawmempool()) > 0)
 
         self.log.info("Waiting for normal broadcast to another peer")
-        self.destinations[1]["node"].wait_for_inv([inv])
+        other_peer.wait_for_inv([inv])
 
         self.log.info("Sending a transaction that is already in the mempool")
         skip_destinations = len(self.destinations)