Added additional checks to channel sorting that sorts by display_name

web/react/components/navbar_dropdown.jsx

@@ -11,16 +11,24 @@ var AboutBuildModal = require('./about_build_modal.jsx');
 var Constants = require('../utils/constants.jsx');
 
 function getStateFromStores() {
-    let teams = [];
-    let teamsObject = UserStore.getTeams();
-    for (let teamId in teamsObject) {
+    const teams = [];
+    const teamsObject = UserStore.getTeams();
+    for (const teamId in teamsObject) {
         if (teamsObject.hasOwnProperty(teamId)) {
             teams.push(teamsObject[teamId]);
         }
     }
-    teams.sort(function sortByDisplayName(teamA, teamB) {
-        let teamADisplayName = teamA.display_name.toLowerCase();
-        let teamBDisplayName = teamB.display_name.toLowerCase();
+    teams.sort((teamA, teamB) => {
+        let teamADisplayName = '';
+        let teamBDisplayName = '';
+
+        if (teamA && teamA.display_name) {
+            teamADisplayName = teamA.display_name.toLowerCase();
+        }
+        if (teamB && teamB.display_name) {
+            teamBDisplayName = teamB.display_name.toLowerCase();
+        }
+
         if (teamADisplayName < teamBDisplayName) {
             return -1;
         } else if (teamADisplayName > teamBDisplayName) {