From 3752c4d14c6d1b87122e9300e5b09d462c263958 Mon Sep 17 00:00:00 2001
From: Joel Lappalainen <joel.lappalainen@cgi.com>
Date: Wed, 19 Jun 2019 21:11:43 +0300
Subject: [PATCH] Don't unsubscribe unless there are existing topics

---
 app/util/mqttClient.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/app/util/mqttClient.js b/app/util/mqttClient.js
index ae7a8aad95..aa53545533 100644
--- a/app/util/mqttClient.js
+++ b/app/util/mqttClient.js
@@ -79,7 +79,9 @@ export function parseMessage(topic, message, agency) {
 export function changeTopics(settings, actionContext) {
   const { client, oldTopics } = settings;
 
-  client.unsubscribe(oldTopics);
+  if (Array.isArray(oldTopics) && oldTopics.length > 0) {
+    client.unsubscribe(oldTopics);
+  }
   // remove existing vehicles/topics
   actionContext.dispatch('RealTimeClientReset');
   const topics = settings.options.map(option => getTopic(option, settings));