From 38b410bd88bedcf5904ebfaf8680f4865dacc2a7 Mon Sep 17 00:00:00 2001
From: Rob Jarawan <32302742+robjarawan@users.noreply.github.com>
Date: Sun, 29 Mar 2026 21:33:04 -0400
Subject: [PATCH] Fix MQTT close() blocking indefinitely on pending publishes

The while loop waiting for pending_publishes to drain has no upper bound.
If the broker never acks, close() hangs forever with EBO capped at 64s.

Add a max_wait bound (uses timeout setting, default 300s) so close()
eventually gives up and proceeds with disconnect.
---
 sarracenia/moth/mqtt.py | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/sarracenia/moth/mqtt.py b/sarracenia/moth/mqtt.py
index 909b6fe43..15413a071 100644
--- a/sarracenia/moth/mqtt.py
+++ b/sarracenia/moth/mqtt.py
@@ -834,17 +834,24 @@ def close(self):
                 time.sleep(0.1)
 
             if hasattr(self, 'pending_publishes'):
-                ebo=0.1
-                while  len(self.pending_publishes) >0:
-                    logger.info( f'waiting {ebo} seconds for last {len(self.pending_publishes)} messages to publish')
+                ebo = 0.1
+                total_wait = 0
+                max_wait = self.o['timeout'] if self.o.get('timeout') else 300
+                while len(self.pending_publishes) > 0:
+                    if total_wait >= max_wait:
+                        logger.warning(f'gave up waiting for {len(self.pending_publishes)} pending publishes after {total_wait:.0f}s')
+                        break
+                    logger.info(f'waiting {ebo} seconds for last {len(self.pending_publishes)} messages to publish')
                     if len(self.unexpected_publishes) < 10:
-                        logger.info( f'messages acknowledged before publish?: {self.unexpected_publishes}')
+                        logger.info(f'messages acknowledged before publish?: {self.unexpected_publishes}')
                     if len(self.pending_publishes) < 10:
-                        logger.info( f'messages awaiting publish: {self.pending_publishes}')
+                        logger.info(f'messages awaiting publish: {self.pending_publishes}')
                     time.sleep(ebo)
+                    total_wait += ebo
                     if ebo < 64:
                         ebo *= 2
-                logger.info('no more pending messages')
+                else:
+                    logger.info('no more pending messages')
             self.client.disconnect()
             self.client.loop_stop()
         self.connected=False