From 36dbeacaa1f95dd76954186a6171055895577aef Mon Sep 17 00:00:00 2001
From: mbench757 <36611650+mbench757@users.noreply.github.com>
Date: Sat, 12 Mar 2022 17:03:20 -0600
Subject: [PATCH] Enable shared subscription for MQTTv5

I've tested this on an ESP32 C3 with mosquitto mqtt broker.   This allows shared subscription topic to find the correct callback for processing.
---
 src/EspMQTTClient.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/EspMQTTClient.cpp b/src/EspMQTTClient.cpp
index 70347fe..2dd40a6 100644
--- a/src/EspMQTTClient.cpp
+++ b/src/EspMQTTClient.cpp
@@ -692,6 +692,14 @@ bool EspMQTTClient::mqttTopicMatch(const String &topic1, const String &topic2)
       if(topic2.substring(t1a.length(), topic2.length()-t1b.length()).indexOf('/') == -1)
         return true;
     }
+  }
+  else if ((i = topic1.indexOf('$')) >= 0)
+  {
+    // shared subscription for MQTTv5
+    if (topic1.startsWith("$share"))
+    {
+      return topic1.endsWith(topic2);
+    }
   } 
   else 
   {