Merge #18890: test: disconnect_nodes should warn if nodes were already disconnected

34e641a564 test: Remove unnecessary disconnect_nodes call in rpc_psbt.py (Danny Lee)
e6e7abd51a test: remove redundant two-way disconnect_nodes calls (Danny Lee)
a9bd1f9adf test: warn if nodes not connected before disconnect_nodes (Danny Lee)

Pull request description:

  There's no harm in calling `disconnect_nodes` for nodes that weren't connected (in this case it's a no-op).  However, detecting this case and logging a warning can help ensure that tests are behaving as expected.

  In addition, since `disconnect_nodes` works bidirectionally, I removed all instances of this pattern:

  ```
  disconnect_nodes(self.nodes[0], 1)
  disconnect_nodes(self.nodes[1], 0)
  ```

ACKs for top commit:
  MarcoFalke:
    review ACK 34e641a564 👔
  amitiuttarwar:
    ACK 34e641a564. Thanks for this test improvement!

Tree-SHA512: 344855ceb46c012d43c13d7c09f44d32dcb7645706d10ae1e4645d9edca54c6c6c13fee26b79480755cdfcdf39b4b5770b36bb03ce71ba002d5be8a27fe008af

test/functional/p2p_node_network_limited.py

@@ -42,9 +42,6 @@ class NodeNetworkLimitedTest(BitcoinTestFramework):
 
     def disconnect_all(self):
         disconnect_nodes(self.nodes[0], 1)
-        disconnect_nodes(self.nodes[1], 0)
-        disconnect_nodes(self.nodes[2], 1)
-        disconnect_nodes(self.nodes[2], 0)
         disconnect_nodes(self.nodes[0], 2)
         disconnect_nodes(self.nodes[1], 2)
 

test/functional/rpc_psbt.py

@@ -43,10 +43,8 @@ class PSBTTest(BitcoinTestFramework):
         online_node = self.nodes[1]
 
         # Disconnect offline node from others
+        # Topology of test network is linear, so this one call is enough
         disconnect_nodes(offline_node, 1)
-        disconnect_nodes(online_node, 0)
-        disconnect_nodes(offline_node, 2)
-        disconnect_nodes(mining_node, 0)
 
         # Create watchonly on online_node
         online_node.createwallet(wallet_name='wonline', disable_private_keys=True)

test/functional/test_framework/test_framework.py

@@ -531,7 +531,6 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
         Split the network of four nodes into nodes 0/1 and 2/3.
         """
         disconnect_nodes(self.nodes[1], 2)
-        disconnect_nodes(self.nodes[2], 1)
         self.sync_all(self.nodes[:2])
         self.sync_all(self.nodes[2:])
 

test/functional/test_framework/util.py

@@ -381,7 +381,21 @@ def set_node_times(nodes, t):
         node.setmocktime(t)
 
 def disconnect_nodes(from_connection, node_num):
-    for peer_id in [peer['id'] for peer in from_connection.getpeerinfo() if "testnode%d" % node_num in peer['subver']]:
+    def get_peer_ids():
+        result = []
+        for peer in from_connection.getpeerinfo():
+            if "testnode{}".format(node_num) in peer['subver']:
+                result.append(peer['id'])
+        return result
+
+    peer_ids = get_peer_ids()
+    if not peer_ids:
+        logger.warning("disconnect_nodes: {} and {} were not connected".format(
+            from_connection.index,
+            node_num
+        ))
+        return
+    for peer_id in peer_ids:
         try:
             from_connection.disconnectnode(nodeid=peer_id)
         except JSONRPCException as e:
@@ -392,7 +406,7 @@ def disconnect_nodes(from_connection, node_num):
                 raise
 
     # wait to disconnect
-    wait_until(lambda: [peer['id'] for peer in from_connection.getpeerinfo() if "testnode%d" % node_num in peer['subver']] == [], timeout=5)
+    wait_until(lambda: not get_peer_ids(), timeout=5)
 
 def connect_nodes(from_connection, node_num):
     ip_port = "127.0.0.1:" + str(p2p_port(node_num))

test/functional/wallet_txn_clone.py

@@ -31,7 +31,6 @@ class TxnMallTest(BitcoinTestFramework):
         # Start with split network:
         super().setup_network()
         disconnect_nodes(self.nodes[1], 2)
-        disconnect_nodes(self.nodes[2], 1)
 
     def run_test(self):
         if self.options.segwit:

test/functional/wallet_txn_doublespend.py

@@ -29,7 +29,6 @@ class TxnMallTest(BitcoinTestFramework):
         # Start with split network:
         super().setup_network()
         disconnect_nodes(self.nodes[1], 2)
-        disconnect_nodes(self.nodes[2], 1)
 
     def run_test(self):
         # All nodes should start with 1,250 BTC: