merge bitcoin#22817: Avoid race after connect_nodes

Due to stricter checks, we can no longer start masternodes in parallel,
as entities used to process `to_connection` checks are reused before the
previous check is completed, resulting in an exception. Since we're
now validating the establishment of a two-way connection, we have to do
it one at a time.

Author: kwvg

test/functional/test_framework/test_framework.py

@@ -695,18 +695,19 @@ def connect_nodes(self, a, b):
         if (a == b):
             return
 
-        def connect_nodes_helper(from_connection, node_num):
-            ip_port = "127.0.0.1:" + str(p2p_port(node_num))
-            from_connection.addnode(ip_port, "onetry")
-            # poll until version handshake complete to avoid race conditions
-            # with transaction relaying
-            # See comments in net_processing:
-            # * Must have a version message before anything else
-            # * Must have a verack message before anything else
-            wait_until_helper(lambda: all(peer['version'] != 0 for peer in from_connection.getpeerinfo()))
-            wait_until_helper(lambda: all(peer['bytesrecv_per_msg'].pop('verack', 0) == 24 for peer in from_connection.getpeerinfo()))
-
-        connect_nodes_helper(self.nodes[a], b)
+        from_connection = self.nodes[a]
+        to_connection = self.nodes[b]
+        ip_port = "127.0.0.1:" + str(p2p_port(b))
+        from_connection.addnode(ip_port, "onetry")
+        # poll until version handshake complete to avoid race conditions
+        # with transaction relaying
+        # See comments in net_processing:
+        # * Must have a version message before anything else
+        # * Must have a verack message before anything else
+        wait_until_helper(lambda: all(peer['version'] != 0 for peer in from_connection.getpeerinfo()))
+        wait_until_helper(lambda: all(peer['version'] != 0 for peer in to_connection.getpeerinfo()))
+        wait_until_helper(lambda: all(peer['bytesrecv_per_msg'].pop('verack', 0) == 24 for peer in from_connection.getpeerinfo()))
+        wait_until_helper(lambda: all(peer['bytesrecv_per_msg'].pop('verack', 0) == 24 for peer in to_connection.getpeerinfo()))
 
     def disconnect_nodes(self, a, b):
         # A node cannot disconnect from itself, bail out early