Follow-up

src/components/left/main/ChatList.tsx

@@ -161,7 +161,7 @@ const ChatList: FC<OwnProps & StateProps & DispatchProps> = ({
       onLoadMore={getMore}
       preloadBackwards={CHAT_LIST_SLICE}
       noFastList
-      isDisabled
+      noScrollRestore
     >
       {viewportIds && viewportIds.length && chatArrays ? (
         renderChats()

src/components/main/ForwardPicker.tsx

@@ -146,7 +146,7 @@ const ForwardPicker: FC<OwnProps & StateProps & DispatchProps> = ({
           className="picker-list custom-scroll"
           items={viewportIds}
           onLoadMore={getMore}
-          isDisabled={Boolean(filter)}
+          noScrollRestore={Boolean(filter)}
         >
           {viewportIds.map((id) => (
             <ListItem

src/components/right/Profile.tsx

@@ -14,10 +14,15 @@ import {
   MediaViewerOrigin, ProfileState, ProfileTabType, SharedMediaType,
 } from '../../types';
 
-import { MEMBERS_SLICE, SHARED_MEDIA_SLICE, SLIDE_TRANSITION_DURATION } from '../../config';
+import {
+  MEMBERS_SLICE,
+  PROFILE_SENSITIVE_AREA,
+  SHARED_MEDIA_SLICE,
+  SLIDE_TRANSITION_DURATION,
+} from '../../config';
 import { IS_TOUCH_ENV } from '../../util/environment';
 import {
-  isChatAdmin, isChatBasicGroup, isChatChannel, isChatGroup, isChatPrivate,
+  isChatAdmin, isChatChannel, isChatGroup, isChatPrivate,
 } from '../../modules/helpers';
 import {
   selectChatMessages,
@@ -57,7 +62,6 @@ type OwnProps = {
 };
 
 type StateProps = {
-  isBasicGroup?: boolean;
   isChannel?: boolean;
   resolvedUserId?: number;
   chatMessages?: Record<number, ApiMessage>;
@@ -90,7 +94,6 @@ const Profile: FC<OwnProps & StateProps & DispatchProps> = ({
   chatId,
   profileState,
   onProfileStateChange,
-  isBasicGroup,
   isChannel,
   resolvedUserId,
   chatMessages,
@@ -307,11 +310,10 @@ const Profile: FC<OwnProps & StateProps & DispatchProps> = ({
       ref={containerRef}
       className="Profile custom-scroll"
       itemSelector={buildInfiniteScrollItemSelector(resultType)}
-      items={viewportIds}
+      items={canRenderContents ? viewportIds : undefined}
       cacheBuster={cacheBuster}
-      sensitiveArea={500}
-      preloadBackwards={resultType === 'members' ? MEMBERS_SLICE : SHARED_MEDIA_SLICE}
-      isDisabled={resultType === 'members' && isBasicGroup}
+      sensitiveArea={PROFILE_SENSITIVE_AREA}
+      preloadBackwards={canRenderContents ? (resultType === 'members' ? MEMBERS_SLICE : SHARED_MEDIA_SLICE) : 0}
       noFastList
       onLoadMore={getMore}
       onScroll={handleScroll}
@@ -370,7 +372,6 @@ export default memo(withGlobal<OwnProps>(
     const { byId: usersById } = global.users;
 
     const isGroup = chat && isChatGroup(chat);
-    const isBasicGroup = chat && isChatBasicGroup(chat);
     const isChannel = chat && isChatChannel(chat);
     const hasMembersTab = isGroup || (isChannel && isChatAdmin(chat!));
     const members = chat && chat.fullInfo && chat.fullInfo.members;
@@ -384,7 +385,6 @@ export default memo(withGlobal<OwnProps>(
     }
 
     return {
-      isBasicGroup,
       isChannel,
       resolvedUserId,
       chatMessages,

src/components/ui/InfiniteScroll.tsx

@@ -17,7 +17,7 @@ type OwnProps = {
   itemSelector?: string;
   preloadBackwards?: number;
   sensitiveArea?: number;
-  isDisabled?: boolean;
+  noScrollRestore?: boolean;
   noFastList?: boolean;
   cacheBuster?: any;
   children: any;
@@ -36,8 +36,8 @@ const InfiniteScroll: FC<OwnProps> = ({
   itemSelector = DEFAULT_LIST_SELECTOR,
   preloadBackwards = DEFAULT_PRELOAD_BACKWARDS,
   sensitiveArea = DEFAULT_SENSITIVE_AREA,
-  // Used to turn off preloading and restoring scroll position (e.g. for frequently re-ordered chat or user lists)
-  isDisabled = false,
+  // Used to turn off restoring scroll position (e.g. for frequently re-ordered chat or user lists)
+  noScrollRestore = false,
   noFastList,
   // Used to re-query `listItemElements` if rendering is delayed by transition
   cacheBuster,
@@ -70,19 +70,20 @@ const InfiniteScroll: FC<OwnProps> = ({
 
   // Initial preload
   useEffect(() => {
-    if (isDisabled || !loadMoreBackwards) {
+    if (!loadMoreBackwards) {
       return;
     }
 
-    if (!items || items.length < preloadBackwards) {
+    if (preloadBackwards > 0 && (!items || items.length < preloadBackwards)) {
       loadMoreBackwards();
-    } else {
-      const { scrollHeight, clientHeight } = containerRef.current!;
-      if (clientHeight && scrollHeight <= clientHeight) {
-        loadMoreBackwards();
-      }
+      return;
     }
-  }, [isDisabled, items, loadMoreBackwards, preloadBackwards]);
+
+    const { scrollHeight, clientHeight } = containerRef.current!;
+    if (clientHeight && scrollHeight <= clientHeight) {
+      loadMoreBackwards();
+    }
+  }, [items, loadMoreBackwards, preloadBackwards]);
 
   // Restore `scrollTop` after adding items
   useLayoutEffect(() => {
@@ -91,7 +92,7 @@ const InfiniteScroll: FC<OwnProps> = ({
 
     state.listItemElements = container.querySelectorAll<HTMLDivElement>(itemSelector);
 
-    if (isDisabled) {
+    if (noScrollRestore) {
       return;
     }
 
@@ -112,7 +113,7 @@ const InfiniteScroll: FC<OwnProps> = ({
     resetScroll(container, newScrollTop);
 
     state.isScrollTopJustUpdated = true;
-  }, [isDisabled, itemSelector, items, cacheBuster]);
+  }, [noScrollRestore, itemSelector, items, cacheBuster]);
 
   const handleScroll = useCallback((e: UIEvent<HTMLDivElement>) => {
     if (loadMoreForwards && loadMoreBackwards) {

src/config.ts

@@ -58,6 +58,7 @@ export const MEMBERS_LOAD_SLICE = 200;
 export const PINNED_MESSAGES_LIMIT = 50;
 export const BLOCKED_LIST_LIMIT = 100;
 export const PROFILE_PHOTOS_LIMIT = 40;
+export const PROFILE_SENSITIVE_AREA = 500;
 
 export const TOP_CHAT_MESSAGES_PRELOAD_LIMIT = 25;
 export const ALL_CHATS_PRELOAD_DISABLED = false;

src/modules/actions/api/chats.ts

@@ -673,7 +673,7 @@ addReducer('loadMoreMembers', (global) => {
   (async () => {
     const { chatId } = selectCurrentMessageList(global) || {};
     const chat = chatId ? selectChat(global, chatId) : undefined;
-    if (!chat) {
+    if (!chat || isChatBasicGroup(chat)) {
       return;
     }