fix: avoid panic when client is confused about rooms

src/api/client_server/sync.rs

@@ -1492,6 +1492,9 @@ pub async fn sync_events_v4_route(
 
     let mut known_subscription_rooms = BTreeSet::new();
     for (room_id, room) in &body.room_subscriptions {
+        if !services().rooms.metadata.exists(room_id)? {
+            continue;
+        }
         let todo_room = todo_rooms
             .entry(room_id.clone())
             .or_insert((BTreeSet::new(), 0, u64::MAX));

src/database/key_value/rooms/timeline.rs

@@ -330,7 +330,7 @@ fn count_to_id(
         .rooms
         .short
         .get_shortroomid(room_id)?
-        .expect("room exists")
+        .ok_or_else(|| Error::bad_database("Looked for bad shortroomid in timeline"))?
         .to_be_bytes()
         .to_vec();
     let mut pdu_id = prefix.clone();

src/service/rooms/event_handler/mod.rs

@@ -190,7 +190,22 @@ impl Service {
             }
 
             if errors >= 5 {
-                break;
+                // Timeout other events
+                match services()
+                    .globals
+                    .bad_event_ratelimiter
+                    .write()
+                    .unwrap()
+                    .entry((*prev_id).to_owned())
+                {
+                    hash_map::Entry::Vacant(e) => {
+                        e.insert((Instant::now(), 1));
+                    }
+                    hash_map::Entry::Occupied(mut e) => {
+                        *e.get_mut() = (Instant::now(), e.get().1 + 1)
+                    }
+                }
+                continue;
             }
 
             if let Some((pdu, json)) = eventid_info.remove(&*prev_id) {