Merge #17445: zmq: Fix due to invalid argument and multiple notifiers

3e730bf90a zmq: Fix due to invalid argument and multiple notifiers (João Barbosa)

Pull request description:

  ZMQ initialization is interrupted if any notifier fails, and in that case all notifiers are destroyed. The notifier shutdown assumes that the initialization had occurred. This is not valid when there are multiple notifiers and any except the last fails to initialize.

  Can be tested by running test/functional/interface_zmq.py from this branch with bitcoind from master.

  Closes #17185.

ACKs for top commit:
  laanwj:
    Code review ACK 3e730bf90a, thanks for adding a test

Tree-SHA512: 5da710e97dcbaa94896d019e75162d470f6d381ee07c60e5b3e9db93d11e8f7ca9bf2c509efa4486199e88c96c3e720cc96b4e35b62725d4c7db8e8e9bf6e09d

src/zmq/zmqpublishnotifier.cpp

@@ -112,7 +112,8 @@ bool CZMQAbstractPublishNotifier::Initialize(void *pcontext)
 
 void CZMQAbstractPublishNotifier::Shutdown()
 {
-    assert(psocket);
+    // Early return if Initialize was not called
+    if (!psocket) return;
 
     int count = mapPublishNotifiers.count(address);
 

test/functional/interface_zmq.py

@@ -59,6 +59,10 @@ class ZMQTest (BitcoinTestFramework):
         # Note that the publishing order is not defined in the documentation and
         # is subject to change.
         import zmq
+
+        # Invalid zmq arguments don't take down the node, see #17185.
+        self.restart_node(0, ["-zmqpubrawtx=foo", "-zmqpubhashtx=bar"])
+
         address = 'tcp://127.0.0.1:28332'
         socket = self.ctx.socket(zmq.SUB)
         socket.set(zmq.RCVTIMEO, 60000)