From 02c7d014cb7aa1fd1c06578eb71592b42cdc6ce1 Mon Sep 17 00:00:00 2001
From: Stephen McLaughlin <44235289+Steve-Mcl@users.noreply.github.com>
Date: Sat, 29 Apr 2023 21:00:26 +0100
Subject: [PATCH] dont use subscriptionIdentifier no broker support

---
 .../node_modules/@node-red/nodes/core/network/10-mqtt.js  | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/packages/node_modules/@node-red/nodes/core/network/10-mqtt.js b/packages/node_modules/@node-red/nodes/core/network/10-mqtt.js
index 0a7ed6dfa..f4fc9ad2c 100644
--- a/packages/node_modules/@node-red/nodes/core/network/10-mqtt.js
+++ b/packages/node_modules/@node-red/nodes/core/network/10-mqtt.js
@@ -697,7 +697,8 @@ module.exports = function(RED) {
                 node.options.rejectUnauthorized = (node.verifyservercert == "true" || node.verifyservercert === true);
             }
         }
-
+        node.v5 = () => node.options && node.options.protocolVersion == 5
+        node.subscriptionIdentifiersAvailable = () => node.v5() && node.serverProperties && node.serverProperties.subscriptionIdentifiersAvailable
         n.autoConnect = n.autoConnect === "false" || n.autoConnect === false ? false : true;
         node.setOptions(n, true);
 
@@ -920,7 +921,12 @@ module.exports = function(RED) {
             };
             node.subscriptions[topic][ref] = sub;
             if (node.connected) {
+                const subIdsAvailable = node.subscriptionIdentifiersAvailable()
                 node._clientOn('message',sub.handler);
+                // if the broker doesn't support subscription identifiers (e.g. AWS core), then don't send them
+                if (options.properties && options.properties.subscriptionIdentifier && subIdsAvailable !== true) {
+                    delete options.properties.subscriptionIdentifier
+                }
                 node.client.subscribe(topic, options);
             }
         };