fix memberlist not containing all members

we were using the prev_batch of the last sync to pass to
/members, but this points at the timeline *before* the last
sync, so wouldn't contain all members. Use the sync token instead.

src/matrix/Session.js

@@ -51,12 +51,13 @@ export class Session {
         this._olmEncryption = null;
         this._megolmEncryption = null;
         this._megolmDecryption = null;
+        this._getSyncToken = () => this.syncToken;
 
         if (olm) {
             this._olmUtil = new olm.Utility();
             this._deviceTracker = new DeviceTracker({
                 storage,
-                getSyncToken: () => this.syncToken,
+                getSyncToken: this._getSyncToken,
                 olmUtil: this._olmUtil,
                 ownUserId: sessionInfo.userId,
                 ownDeviceId: sessionInfo.deviceId,
@@ -241,6 +242,7 @@ export class Session {
     createRoom(roomId, pendingEvents) {
         const room = new Room({
             roomId,
+            getSyncToken: this._getSyncToken,
             storage: this._storage,
             emitCollectionChange: this._roomUpdateCallback,
             hsApi: this._hsApi,

src/matrix/room/Room.js

@@ -28,7 +28,7 @@ import {Heroes} from "./members/Heroes.js";
 import {EventEntry} from "./timeline/entries/EventEntry.js";
 
 export class Room extends EventEmitter {
-	constructor({roomId, storage, hsApi, emitCollectionChange, sendScheduler, pendingEvents, user, createRoomEncryption}) {
+	constructor({roomId, storage, hsApi, emitCollectionChange, sendScheduler, pendingEvents, user, createRoomEncryption, getSyncToken}) {
         super();
         this._roomId = roomId;
         this._storage = storage;
@@ -44,6 +44,7 @@ export class Room extends EventEmitter {
         this._memberList = null;
         this._createRoomEncryption = createRoomEncryption;
         this._roomEncryption = null;
+        this._getSyncToken = getSyncToken;
 	}
 
     async notifyRoomKeys(roomKeys) {
@@ -270,6 +271,7 @@ export class Room extends EventEmitter {
                 roomId: this._roomId,
                 hsApi: this._hsApi,
                 storage: this._storage,
+                syncToken: this._getSyncToken(),
                 // to handle race between /members and /sync
                 setChangedMembersMap: map => this._changedMembersDuringSync = map,
             });

src/matrix/room/RoomSummary.js

@@ -31,12 +31,8 @@ function applySyncResponse(data, roomResponse, membership, isInitialSync, isTime
     if (roomResponse.state) {
         data = roomResponse.state.events.reduce(processStateEvent, data);
     }
-    if (roomResponse.timeline) {
+    const {timeline} = roomResponse;
-        const {timeline} = roomResponse;
+    if (timeline && Array.isArray(timeline.events)) {
-        if (timeline.prev_batch) {
-            data = data.cloneIfNeeded();
-            data.lastPaginationToken = timeline.prev_batch;
-        }
         data = timeline.events.reduce((data, event) => {
             if (typeof event.state_key === "string") {
                 return processStateEvent(data, event);
@@ -150,7 +146,6 @@ class SummaryData {
         this.canonicalAlias = copy ? copy.canonicalAlias : null;
         this.hasFetchedMembers = copy ? copy.hasFetchedMembers : false;
         this.isTrackingMembers = copy ? copy.isTrackingMembers : false;
-        this.lastPaginationToken = copy ? copy.lastPaginationToken : null;
         this.avatarUrl = copy ? copy.avatarUrl : null;
         this.notificationCount = copy ? copy.notificationCount : 0;
         this.highlightCount = copy ? copy.highlightCount : 0;
@@ -244,11 +239,7 @@ export class RoomSummary {
     get isTrackingMembers() {
         return this._data.isTrackingMembers;
     }
-
+    
-    get lastPaginationToken() {
-        return this._data.lastPaginationToken;
-    }
-
     get tags() {
         return this._data.tags;
     }

src/matrix/room/members/load.js

@@ -25,13 +25,13 @@ async function loadMembers({roomId, storage}) {
     return memberDatas.map(d => new RoomMember(d));
 }
 
-async function fetchMembers({summary, roomId, hsApi, storage, setChangedMembersMap}) {
+async function fetchMembers({summary, syncToken, roomId, hsApi, storage, setChangedMembersMap}) {
     // if any members are changed by sync while we're fetching members,
     // they will end up here, so we check not to override them
     const changedMembersDuringSync = new Map();
     setChangedMembersMap(changedMembersDuringSync);
     
-    const memberResponse = await hsApi.members(roomId, {at: summary.lastPaginationToken}).response();
+    const memberResponse = await hsApi.members(roomId, {at: syncToken}).response();
 
     const txn = await storage.readWriteTxn([
         storage.storeNames.roomSummary,