Merge pull request #713 from Thulinma/noMoreDuplicates

Fixed duplicate messages appearing in timeline if server sent them

src/Cache.cpp

@@ -2999,12 +2999,15 @@ Cache::saveTimelineMessages(lmdb::txn &txn,
                         eventsDb.put(txn, redaction->redacts, event.dump());
                         eventsDb.put(txn, redaction->event_id, json(*redaction).dump());
                 } else {
-                        eventsDb.put(txn, event_id, event.dump());
+                        first = false;
 
+                        // This check protects against duplicates in the timeline. If the event_id
+                        // is already in the DB, we skip putting it (again) in ordered DBs, and only
+                        // update the event itself and its relations.
+                        std::string_view unused_read;
+                        if (!eventsDb.get(txn, event_id, unused_read)) {
                                 ++index;
 
-                        first = false;
-
                                 nhlog::db()->debug("saving '{}'", orderEntry.dump());
 
                                 cursor.put(lmdb::to_sv(index), orderEntry.dump(), MDB_APPEND);
@@ -3017,6 +3020,10 @@ Cache::saveTimelineMessages(lmdb::txn &txn,
 
                                         msg2orderDb.put(txn, event_id, lmdb::to_sv(msgIndex));
                                 }
+                        } else {
+                                nhlog::db()->warn("duplicate event '{}'", orderEntry.dump());
+                        }
+                        eventsDb.put(txn, event_id, event.dump());
 
                         auto relations = mtx::accessors::relations(e);
                         if (!relations.relations.empty()) {
@@ -3078,8 +3085,12 @@ Cache::saveOldMessages(const std::string &room_id, const mtx::responses::Message
                 auto event                = mtx::accessors::serialize_event(e);
                 event_id_val              = event["event_id"].get<std::string>();
                 std::string_view event_id = event_id_val;
-                eventsDb.put(txn, event_id, event.dump());
 
+                // This check protects against duplicates in the timeline. If the event_id is
+                // already in the DB, we skip putting it (again) in ordered DBs, and only update the
+                // event itself and its relations.
+                std::string_view unused_read;
+                if (!eventsDb.get(txn, event_id, unused_read)) {
                         --index;
 
                         json orderEntry        = json::object();
@@ -3095,6 +3106,8 @@ Cache::saveOldMessages(const std::string &room_id, const mtx::responses::Message
 
                                 msg2orderDb.put(txn, event_id, lmdb::to_sv(msgIndex));
                         }
+                }
+                eventsDb.put(txn, event_id, event.dump());
 
                 auto relations = mtx::accessors::relations(e);
                 if (!relations.relations.empty()) {