bug fixes: crash in editing group member permissions, fnd not working sometimes, var -> let, const

src/widgets/contact-list.jsx

@@ -27,11 +27,11 @@ class ContactList extends React.Component {
     const contactNodes = [];
     if (this.props.contacts && this.props.contacts.length > 0) {
       this.props.contacts.map((c) => {
-        var key = c.topic ? c.topic : c.user;
+        let key = c.topic ? c.topic : c.user;
         // If filter function is provided, filter out the items
         // which don't satisfy the condition.
         if (this.props.filterFunc && this.props.filter) {
-          var content = [key];
+          let content = [key];
           if (c.private && c.private.comment) {
             content.push(('' + c.private.comment).toLowerCase());
           }
@@ -43,10 +43,10 @@ class ContactList extends React.Component {
           }
         }
 
-        var selected = showCheckmark ?
+        let selected = showCheckmark ?
           (this.props.topicSelected.indexOf(key) > -1) :
           (this.props.topicSelected === key);
-        var badges = [];
+        let badges = [];
         if (this.props.showMode) {
           if (key === this.props.myUserId) {
             badges.push({name: formatMessage(messages.badge_you), color: 'green'});
@@ -55,7 +55,7 @@ class ContactList extends React.Component {
             badges.push({name: formatMessage(messages.badge_owner), color: 'blue'});
           }
         }
-        var comment = Array.isArray(c.private) ?
+        let comment = Array.isArray(c.private) ?
           c.private.join(',') : (c.private ? c.private.comment : null);
 
         contactNodes.push(

src/widgets/contact.jsx

@@ -36,9 +36,9 @@ export default class Contact extends React.Component {
       // FIXME: this is probably wrong for RTL languages.
       title = title.substring(0, 28) + '...';
     }
-    let online = this.props.now ? 'online' : 'offline';
-    let avatar = this.props.avatar ? this.props.avatar : true;
-    let badges = this.props.badges.slice();
+    const online = this.props.now ? 'online' : 'offline';
+    const avatar = this.props.avatar ? this.props.avatar : true;
+    const badges = this.props.badges ? this.props.badges.slice() : [];
     if (this.props.showMode && this.props.acs) {
       badges.push({name: this.props.acs.getMode(), key: 'mode'});
     }

src/widgets/group-subs.jsx

@@ -8,21 +8,11 @@ import { makeImageUrl } from '../lib/blob-helpers.js';
 export default class GroupSubs extends React.Component {
   constructor(props) {
     super(props);
-
-    this.state = {
-      onlineSubs: props.subscribers || []
-    };
-  }
-
-  static getDerivedStateFromProps(nextProps, prevState) {
-    return {
-      onlineSubs: nextProps.subscribers ? nextProps.subscribers : []
-    };
   }
 
   render() {
-    var usersOnline = [];
-    this.state.onlineSubs.map((sub) => {
+    const usersOnline = [];
+    (this.props.subscribers || []).map((sub) => {
       usersOnline.push(
         <div className="avatar-box" key={sub.user}>
           <LetterTile