From fb7a3303d627812651f7a4f87fe25ea6e74f86b3 Mon Sep 17 00:00:00 2001
From: Alex Hultman <alexhultman@gmail.com>
Date: Wed, 20 May 2020 17:27:06 +0200
Subject: [PATCH] Clear no longer subscribed-to Topics when draining

---
 src/TopicTree.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/TopicTree.h b/src/TopicTree.h
index c1ee999..2ca4f10 100644
--- a/src/TopicTree.h
+++ b/src/TopicTree.h
@@ -291,6 +291,11 @@ public:
         for (int i = 0; i < numTriggeredTopics; i++) {
             if (triggeredTopics[i]->subs.size()) {
                 triggeredTopics[numFilteredTriggeredTopics++] = triggeredTopics[i];
+            } else {
+                /* If we no longer have any subscribers, yet still keep this Topic alive (parent),
+                 * make sure to clear its potential messages. */
+                triggeredTopics[i]->messages.clear();
+                triggeredTopics[i]->triggered = false;
             }
         }
         numTriggeredTopics = numFilteredTriggeredTopics;