fix notifications not catching up with "read" status as intended

changelog.d/unreads-sync.fix

@@ -0,0 +1 @@
+unread notifications should now properly catch up (eventually) in polling mode

src/services/api/api.service.js

@@ -671,6 +671,7 @@ const fetchTimeline = ({
   timeline,
   credentials,
   since = false,
+  minId = false,
   until = false,
   userId = false,
   listId = false,
@@ -705,6 +706,9 @@ const fetchTimeline = ({
     url = url(listId)
   }
 
+  if (minId) {
+    params.push(['min_id', minId])
+  }
   if (since) {
     params.push(['since_id', since])
   }

src/services/notifications_fetcher/notifications_fetcher.service.js

@@ -49,9 +49,11 @@ const fetchAndUpdate = ({ store, credentials, older = false, since }) => {
     // The normal maxId-check does not tell if older notifications have changed
     const notifications = timelineData.data
     const readNotifsIds = notifications.filter(n => n.seen).map(n => n.id)
-    const numUnseenNotifs = notifications.length - readNotifsIds.length
-    if (numUnseenNotifs > 0 && readNotifsIds.length > 0) {
-      args.since = Math.max(...readNotifsIds)
+    const unreadNotifsIds = notifications.filter(n => !n.seen).map(n => n.id)
+    if (readNotifsIds.length > 0 && readNotifsIds.length > 0) {
+      const minId = Math.min(...unreadNotifsIds) // Oldest known unread notification
+      args.since = false // Don't use since_id since it sorta conflicts with min_id
+      args.minId = minId - 1 // go beyond
       fetchNotifications({ store, args, older })
     }