Fix unread notification count when polling (#16272)

* Fix unread notification count when polling

Fixes #16236

* Immediately fetch markers to avoid incorrect unread notification count

app/javascript/mastodon/features/ui/index.js

@@ -361,9 +361,9 @@ class UI extends React.PureComponent {
       this.props.dispatch(closeOnboarding());
     }
 
+    this.props.dispatch(fetchMarkers());
     this.props.dispatch(expandHomeTimeline());
     this.props.dispatch(expandNotifications());
-    setTimeout(() => this.props.dispatch(fetchMarkers()), 500);
     setTimeout(() => this.props.dispatch(fetchFilters()), 500);
 
     this.hotkeys.__mousetrap__.stopCallback = (e, element) => {

app/javascript/mastodon/reducers/notifications.js

@@ -106,7 +106,7 @@ const expandNormalizedNotifications = (state, notifications, next, isLoadingRece
     }
 
     if (shouldCountUnreadNotifications(state)) {
-      mutable.update('unread', unread => unread + items.count(item => compareId(item.get('id'), lastReadId) > 0));
+      mutable.set('unread', mutable.get('pendingItems').count(item => item !== null) + mutable.get('items').count(item => item && compareId(item.get('id'), lastReadId) > 0));
     } else {
       const mostRecent = items.find(item => item !== null);
       if (mostRecent && compareId(lastReadId, mostRecent.get('id')) < 0) {