From 14855f3255b91960079da5a4ff38a8ceb3441222 Mon Sep 17 00:00:00 2001
From: paweldomas <pawel.domas@jitsi.org>
Date: Thu, 19 Mar 2020 12:40:36 -0500
Subject: [PATCH] fix(features/notifications): crash on undefined participant

---
 react/features/notifications/middleware.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/react/features/notifications/middleware.js b/react/features/notifications/middleware.js
index 02f3b876c..d30e1e1a8 100644
--- a/react/features/notifications/middleware.js
+++ b/react/features/notifications/middleware.js
@@ -84,9 +84,10 @@ MiddlewareRegistry.register(store => next => action => {
 
         const { id, role } = action.participant;
         const state = store.getState();
-        const { role: oldRole } = getParticipantById(state, id);
+        const oldParticipant = getParticipantById(state, id);
+        const oldRole = oldParticipant?.role;
 
-        if (oldRole !== role && role === PARTICIPANT_ROLE.MODERATOR) {
+        if (oldRole && oldRole !== role && role === PARTICIPANT_ROLE.MODERATOR) {
             const displayName = getParticipantDisplayName(state, id);
 
             store.dispatch(showNotification({