Remove supergroup migrate messages.

Telegram/Resources/langs/lang.strings

@@ -899,7 +899,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 "lng_action_changed_title_channel" = "Channel name was changed to «{title}»";
 "lng_action_created_chat" = "{from} created group «{title}»";
 "lng_action_created_channel" = "Channel created";
-"lng_action_group_migrate" = "The group was upgraded to a supergroup";
 "lng_action_pinned_message" = "{from} pinned «{text}»";
 "lng_action_pinned_media" = "{from} pinned {media}";
 "lng_action_pinned_media_photo" = "a photo";

Telegram/SourceFiles/apiwrap.cpp

@@ -416,7 +416,7 @@ void ApiWrap::savePinnedOrder() {
 	const auto &order = _session->data().pinnedDialogsOrder();
 	auto peers = QVector<MTPInputDialogPeer>();
 	peers.reserve(order.size());
-	for (const auto &pinned : base::reversed(order)) {
+	for (const auto &pinned : ranges::view::reverse(order)) {
 		if (const auto history = pinned.history()) {
 			peers.push_back(MTP_inputDialogPeer(history->peer->input));
 		} else if (const auto feed = pinned.feed()) {
@@ -708,7 +708,7 @@ void ApiWrap::requestDialogEntry(
 		MTP_vector(std::move(peers))
 	)).done([=](const MTPmessages_PeerDialogs &result) {
 		applyPeerDialogs(result);
-		historyDialogEntryApplied(history);
+		history->dialogEntryApplied();
 		finalize();
 	}).fail([=](const RPCError &error) {
 		finalize();
@@ -744,7 +744,7 @@ void ApiWrap::requestDialogEntries(
 	)).done([=](const MTPmessages_PeerDialogs &result) {
 		applyPeerDialogs(result);
 		for (const auto history : histories) {
-			historyDialogEntryApplied(history);
+			history->dialogEntryApplied();
 		}
 		finalize(histories);
 	}).fail([=](const RPCError &error) {
@@ -778,89 +778,41 @@ void ApiWrap::applyPeerDialogs(const MTPmessages_PeerDialogs &dialogs) {
 	_session->data().sendHistoryChangeNotifications();
 }
 
-void ApiWrap::historyDialogEntryApplied(not_null<History*> history) {
-	if (!history->lastMessage()) {
-		if (const auto chat = history->peer->asChat()) {
-			if (!chat->haveLeft()) {
-				Local::addSavedPeer(
-					history->peer,
-					ParseDateTime(history->chatsListTimeId()));
-			}
-		} else if (const auto channel = history->peer->asChannel()) {
-			const auto inviter = channel->inviter;
-			if (inviter != 0 && channel->amIn()) {
-				if (const auto from = App::userLoaded(inviter)) {
-					history->unloadBlocks();
-					history->addNewerSlice(QVector<MTPMessage>());
-					history->insertJoinedMessage(true);
-				}
-			}
-		} else {
-			App::main()->deleteConversation(history->peer, false);
-		}
-		return;
-	}
-
-	if (history->chatsListTimeId() != 0 && history->loadedAtBottom()) {
-		if (const auto channel = history->peer->asChannel()) {
-			const auto inviter = channel->inviter;
-			if (inviter != 0
-				&& history->chatsListTimeId() <= channel->inviteDate
-				&& channel->amIn()) {
-				if (const auto from = App::userLoaded(inviter)) {
-					history->insertJoinedMessage(true);
-				}
-			}
-		}
-	}
-	history->updateChatListExistence();
-}
-
 void ApiWrap::applyFeedDialogs(
 		not_null<Data::Feed*> feed,
 		const MTPmessages_Dialogs &dialogs) {
-	const auto [dialogsList, messagesList] = [&] {
+	if (dialogs.type() == mtpc_messages_dialogsNotModified) {
-		const auto process = [&](const auto &data) {
+		LOG(("API Error: "
-			App::feedUsers(data.vusers);
+			"messages.dialogsNotModified in ApiWrap::applyFeedDialogs."));
-			App::feedChats(data.vchats);
+		return;
-			return std::make_tuple(&data.vdialogs.v, &data.vmessages.v);
+	}
-		};
-		switch (dialogs.type()) {
-		case mtpc_messages_dialogs:
-			return process(dialogs.c_messages_dialogs());
-
-		case mtpc_messages_dialogsSlice:
-			LOG(("API Error: "
-				"Unexpected dialogsSlice in feed dialogs list."));
-			return process(dialogs.c_messages_dialogsSlice());
-		}
-		Unexpected("Type in DialogsWidget::dialogsReceived");
-	}();
-
-	App::feedMsgs(*messagesList, NewMessageLast);
 
 	auto channels = std::vector<not_null<ChannelData*>>();
-	channels.reserve(dialogsList->size());
+	dialogs.match([&](const MTPDmessages_dialogsNotModified &) {
-	for (const auto &dialog : *dialogsList) {
+		Unexpected("Type in ApiWrap::applyFeedDialogs.");
-		switch (dialog.type()) {
+	}, [&](const auto &data) {
-		case mtpc_dialog: {
+		App::feedUsers(data.vusers);
-			if (const auto peerId = peerFromMTP(dialog.c_dialog().vpeer)) {
+		App::feedChats(data.vchats);
-				if (peerIsChannel(peerId)) {
+		App::feedMsgs(data.vmessages.v, NewMessageLast);
-					const auto history = App::history(peerId);
+		channels.reserve(data.vdialogs.v.size());
-					history->applyDialog(dialog.c_dialog());
+		for (const auto &dialog : data.vdialogs.v) {
-					channels.emplace_back(history->peer->asChannel());
+			dialog.match([&](const MTPDdialog &data) {
-				} else {
+				if (const auto peerId = peerFromMTP(data.vpeer)) {
-					LOG(("API Error: "
+					if (peerIsChannel(peerId)) {
-						"Unexpected non-channel in feed dialogs list."));
+						const auto history = App::history(peerId);
+						history->applyDialog(dialog.c_dialog());
+						channels.emplace_back(history->peer->asChannel());
+					} else {
+						LOG(("API Error: "
+							"Unexpected peer in feed dialogs list."));
+					}
 				}
-			}
+			//}, [&](const MTPDdialogFeed &) { // #feed
-		} break;
+			//	LOG(("API Error: "
-		//case mtpc_dialogFeed: { // #feed
+			//		"Unexpected dialogFeed in feed dialogs list."));
-		//	LOG(("API Error: Unexpected dialogFeed in feed dialogs list."));
+			});
-		//} break;
-		default: Unexpected("Type in DialogsInner::dialogsReceived");
 		}
-	}
+	});
 
 	feed->setChannels(channels);
 	_session->data().sendHistoryChangeNotifications();
@@ -878,6 +830,34 @@ void ApiWrap::changeDialogUnreadMark(
 	)).send();
 }
 
+void ApiWrap::requestFakeChatListMessage(
+		not_null<History*> history) {
+	if (_fakeChatListRequests.contains(history)) {
+		return;
+	}
+
+	_fakeChatListRequests.emplace(history);
+	request(MTPmessages_GetHistory(
+		history->peer->input,
+		MTP_int(0),  // offset_id
+		MTP_int(0),  // offset_date
+		MTP_int(0),  // add_offset
+		MTP_int(2),  // limit
+		MTP_int(0),  // max_id
+		MTP_int(0),  // min_id
+		MTP_int(0)
+	)).done([=](const MTPmessages_Messages &result) {
+		_fakeChatListRequests.erase(history);
+		history->setFakeChatListMessageFrom(result);
+	}).fail([=](const RPCError &error) {
+		_fakeChatListRequests.erase(history);
+		history->setFakeChatListMessageFrom(MTP_messages_messages(
+			MTP_vector<MTPMessage>(0),
+			MTP_vector<MTPChat>(0),
+			MTP_vector<MTPUser>(0)));
+	}).send();
+}
+
 void ApiWrap::requestFullPeer(not_null<PeerData*> peer) {
 	if (_fullPeerRequests.contains(peer)) {
 		return;
@@ -1768,9 +1748,7 @@ void ApiWrap::deleteAllFromUserSend(
 		if (offset > 0) {
 			deleteAllFromUserSend(channel, from);
 		} else if (const auto history = App::historyLoaded(channel)) {
-			if (!history->lastMessageKnown()) {
+			history->requestChatListMessage();
-				requestDialogEntry(history);
-			}
 		}
 	}).send();
 }
@@ -2303,9 +2281,11 @@ int ApiWrap::OnlineTillFromStatus(
 
 void ApiWrap::clearHistory(not_null<PeerData*> peer) {
 	auto deleteTillId = MsgId(0);
-	if (auto history = App::historyLoaded(peer->id)) {
+	if (const auto history = App::historyLoaded(peer->id)) {
 		if (const auto last = history->lastMessage()) {
 			deleteTillId = last->id;
+		}
+		if (const auto last = history->chatListMessage()) {
 			Local::addSavedPeer(history->peer, ItemDateTime(last));
 		}
 		history->clear();

Telegram/SourceFiles/apiwrap.h

@@ -90,6 +90,7 @@ public:
 	//	const std::vector<not_null<ChannelData*>> &channels);
 	void changeDialogUnreadMark(not_null<History*> history, bool unread);
 	//void changeDialogUnreadMark(not_null<Data::Feed*> feed, bool unread); // #feed
+	void requestFakeChatListMessage(not_null<History*> history);
 
 	void requestFullPeer(not_null<PeerData*> peer);
 	void requestPeer(not_null<PeerData*> peer);
@@ -428,7 +429,6 @@ private:
 	QVector<MTPInputMessage> collectMessageIds(const MessageDataRequests &requests);
 	MessageDataRequests *messageDataRequests(ChannelData *channel, bool onlyExisting = false);
 	void applyPeerDialogs(const MTPmessages_PeerDialogs &dialogs);
-	void historyDialogEntryApplied(not_null<History*> history);
 	void applyFeedDialogs(
 		not_null<Data::Feed*> feed,
 		const MTPmessages_Dialogs &dialogs);
@@ -666,6 +666,7 @@ private:
 	base::flat_map<
 		not_null<History*>,
 		std::vector<Fn<void()>>> _dialogRequests;
+	base::flat_set<not_null<History*>> _fakeChatListRequests;
 
 	base::flat_map<not_null<History*>, mtpRequestId> _unreadMentionsRequests;
 

Telegram/SourceFiles/app.cpp

@@ -380,7 +380,7 @@ namespace App {
 			if (j != data->cend()) {
 				const auto history = (*j)->history();
 				(*j)->destroy();
-				if (!history->lastMessageKnown()) {
+				if (!history->chatListMessageKnown()) {
 					historiesToCheck.emplace(history);
 				}
 			} else if (affectedHistory) {
@@ -388,7 +388,7 @@ namespace App {
 			}
 		}
 		for (const auto history : historiesToCheck) {
-			Auth().api().requestDialogEntry(history);
+			history->requestChatListMessage();
 		}
 	}
 

Telegram/SourceFiles/base/algorithm.h

@@ -24,6 +24,12 @@ inline constexpr size_t array_size(const Type(&)[Size]) {
 	return Size;
 }
 
+template <typename Container, typename T>
+inline bool contains(const Container &container, const T &value) {
+	const auto end = std::end(container);
+	return std::find(std::begin(container), end, value) != end;
+}
+
 } // namespace base
 
 template <typename T>

Telegram/SourceFiles/boxes/confirm_box.cpp

@@ -605,25 +605,26 @@ void DeleteMessagesBox::deleteAndClear() {
 		_deleteConfirmedCallback();
 	}
 
-	QMap<PeerData*, QVector<MTPint>> idsByPeer;
+	base::flat_map<not_null<PeerData*>, QVector<MTPint>> idsByPeer;
 	for (const auto itemId : _ids) {
-		if (auto item = App::histItemById(itemId)) {
+		if (const auto item = App::histItemById(itemId)) {
-			auto history = item->history();
+			const auto history = item->history();
-			auto wasOnServer = (item->id > 0);
+			const auto wasOnServer = IsServerMsgId(item->id);
-			auto wasLast = (history->lastMessage() == item);
+			const auto wasLast = (history->lastMessage() == item);
+			const auto wasInChats = (history->chatListMessage() == item);
 			item->destroy();
 
 			if (wasOnServer) {
 				idsByPeer[history->peer].push_back(MTP_int(itemId.msg));
-			} else if (wasLast && !history->lastMessageKnown()) {
+			} else if (wasLast || wasInChats) {
-				history->session().api().requestDialogEntry(history);
+				history->requestChatListMessage();
 			}
 		}
 	}
 
-	auto forEveryone = _forEveryone ? _forEveryone->checked() : false;
+	const auto revoke = _forEveryone ? _forEveryone->checked() : false;
-	for (auto i = idsByPeer.cbegin(), e = idsByPeer.cend(); i != e; ++i) {
+	for (const auto &[peer, ids] : idsByPeer) {
-		App::main()->deleteMessages(i.key(), i.value(), forEveryone);
+		App::main()->deleteMessages(peer, ids, revoke);
 	}
 	Ui::hideLayer();
 	Auth().data().sendHistoryChangeNotifications();

Telegram/SourceFiles/boxes/create_poll_box.cpp

@@ -435,7 +435,7 @@ void Options::removeEmptyTail() {
 		_list,
 		&Option::hasFocus);
 	const auto end = _list.end();
-	auto reversed = ranges::view::reverse(_list);
+	const auto reversed = ranges::view::reverse(_list);
 	const auto emptyItem = ranges::find_if(
 		reversed,
 		ranges::not_fn(&Option::isEmpty)).base();

Telegram/SourceFiles/boxes/send_files_box.cpp

@@ -1830,7 +1830,7 @@ void SendFilesBox::updateControlsGeometry() {
 		_sendPhotos.data(),
 		_sendFiles.data()
 	};
-	for (auto pointer : base::reversed(pointers)) {
+	for (const auto pointer : ranges::view::reverse(pointers)) {
 		if (pointer) {
 			pointer->moveToLeft(
 				st::boxPhotoPadding.left(),

Telegram/SourceFiles/boxes/share_box.cpp

@@ -966,7 +966,7 @@ void ShareBox::Inner::updateFilter(QString filter) {
 				if (toFilter) {
 					_filtered.reserve(toFilter->size());
 					for (const auto row : *toFilter) {
-						auto &nameWords = row->entry()->chatsListNameWords();
+						const auto &nameWords = row->entry()->chatListNameWords();
 						auto nb = nameWords.cbegin(), ne = nameWords.cend(), ni = nb;
 						for (fi = fb; fi != fe; ++fi) {
 							auto filterName = *fi;

Telegram/SourceFiles/core/utils.h

@@ -36,12 +36,6 @@ inline constexpr D up_cast(T object) {
 	}
 }
 
-template <typename Container, typename T>
-inline bool contains(const Container &container, const T &value) {
-	auto end = std::end(container);
-	return std::find(std::begin(container), end, value) != end;
-}
-
 // We need a custom comparator for std::set<std::unique_ptr<T>>::find to work with pointers.
 // thanks to http://stackoverflow.com/questions/18939882/raw-pointer-lookup-for-sets-of-unique-ptrs
 template <typename T>
@@ -86,28 +80,6 @@ using set_of_unique_ptr = std::set<std::unique_ptr<T>, base::pointer_comparator<
 template <typename T>
 using set_of_shared_ptr = std::set<std::shared_ptr<T>, base::pointer_comparator<T>>;
 
-// Thanks https://stackoverflow.com/a/28139075
-
-template <typename Container>
-struct reversion_wrapper {
-	Container &container;
-};
-
-template <typename Container>
-auto begin(reversion_wrapper<Container> wrapper) {
-	return std::rbegin(wrapper.container);
-}
-
-template <typename Container>
-auto end(reversion_wrapper<Container> wrapper) {
-	return std::rend(wrapper.container);
-}
-
-template <typename Container>
-reversion_wrapper<Container> reversed(Container &&container) {
-	return { container };
-}
-
 template <typename Value, typename From, typename Till>
 inline bool in_range(Value &&value, From &&from, Till &&till) {
 	return (value >= from) && (value < till);

Telegram/SourceFiles/data/data_feed.cpp

@@ -31,14 +31,22 @@ namespace Data {
 //		data.vid.v));
 //}
 
-Feed::Feed(FeedId id, not_null<Data::Session*> parent)
+Feed::Feed(not_null<Data::Session*> owner, FeedId id)
 : Entry(this)
 , _id(id)
-, _parent(parent)
+, _owner(owner)
 , _name(lang(lng_feed_name)) {
 	indexNameParts();
 }
 
+Data::Session &Feed::owner() const {
+	return *_owner;
+}
+
+AuthSession &Feed::session() const {
+	return _owner->session();
+}
+
 FeedId Feed::id() const {
 	return _id;
 }
@@ -74,17 +82,17 @@ void Feed::registerOne(not_null<ChannelData*> channel) {
 	if (!base::contains(_channels, history)) {
 		const auto invisible = (_channels.size() < 2);
 		_channels.push_back(history);
-		_parent->session().storage().invalidate(
+		session().storage().invalidate(
 			Storage::FeedMessagesInvalidate(_id));
 
-		if (history->lastMessageKnown()) {
+		if (history->chatListMessageKnown()) {
-			if (const auto last = history->lastMessage()) {
+			if (const auto last = history->chatListMessage()) {
-				if (justUpdateLastMessage(last)) {
+				if (justUpdateChatListMessage(last)) {
 					updateChatListEntry();
 				}
 			}
-		} else if (lastMessageKnown()) {
+		} else if (chatListMessageKnown()) {
-			_parent->session().api().requestDialogEntry(history);
+			history->requestChatListMessage();
 		}
 		if (unreadCountKnown()) {
 			if (history->unreadCountKnown()) {
@@ -96,7 +104,7 @@ void Feed::registerOne(not_null<ChannelData*> channel) {
 					unreadCountChanged(count, history->mute() ? count : 0);
 				}
 			} else if (!_settingChannels) {
-				_parent->session().api().requestDialogEntry(this);
+				session().api().requestDialogEntry(this);
 			}
 		}
 		if (invisible && _channels.size() > 1) {
@@ -107,7 +115,7 @@ void Feed::registerOne(not_null<ChannelData*> channel) {
 		} else {
 			history->updateChatListExistence();
 		}
-		_parent->notifyFeedUpdated(this, FeedUpdateFlag::Channels);
+		_owner->notifyFeedUpdated(this, FeedUpdateFlag::Channels);
 	}
 }
 
@@ -117,13 +125,13 @@ void Feed::unregisterOne(not_null<ChannelData*> channel) {
 	if (i != end(_channels)) {
 		const auto visible = (_channels.size() > 1);
 		_channels.erase(i, end(_channels));
-		_parent->session().storage().remove(
+		session().storage().remove(
 			Storage::FeedMessagesRemoveAll(_id, channel->bareId()));
 
-		if (lastMessageKnown()) {
+		if (chatListMessageKnown()) {
-			if (const auto last = lastMessage()) {
+			if (const auto last = chatListMessage()) {
 				if (last->history() == history) {
-					recountLastMessage();
+					recountChatListMessage();
 				}
 			}
 		}
@@ -133,7 +141,7 @@ void Feed::unregisterOne(not_null<ChannelData*> channel) {
 					unreadCountChanged(delta, history->mute() ? delta : 0);
 				}
 			} else {
-				_parent->session().api().requestDialogEntry(this);
+				session().api().requestDialogEntry(this);
 			}
 		}
 		if (visible && _channels.size() < 2) {
@@ -144,14 +152,14 @@ void Feed::unregisterOne(not_null<ChannelData*> channel) {
 		} else {
 			history->updateChatListExistence();
 		}
-		_parent->notifyFeedUpdated(this, FeedUpdateFlag::Channels);
+		_owner->notifyFeedUpdated(this, FeedUpdateFlag::Channels);
 	}
 }
 
-void Feed::updateLastMessage(not_null<HistoryItem*> item) {
+void Feed::updateChatListMessage(not_null<HistoryItem*> item) {
-	if (justUpdateLastMessage(item)) {
+	if (justUpdateChatListMessage(item)) {
-		if (_lastMessage && *_lastMessage) {
+		if (_chatListMessage && *_chatListMessage) {
-			setChatsListTimeId((*_lastMessage)->date());
+			setChatListTimeId((*_chatListMessage)->date());
 		}
 	}
 }
@@ -206,7 +214,7 @@ bool Feed::channelsLoaded() const {
 void Feed::setChannelsLoaded(bool loaded) {
 	if (_channelsLoaded != loaded) {
 		_channelsLoaded = loaded;
-		_parent->notifyFeedUpdated(this, FeedUpdateFlag::Channels);
+		_owner->notifyFeedUpdated(this, FeedUpdateFlag::Channels);
 	}
 }
 
@@ -249,74 +257,72 @@ void Feed::changeChannelsList(
 	// We assume the last message was correct before requesting the list.
 	// So we save it and don't allow channels from the list to change it.
 	// After that we restore it.
-	const auto oldLastMessage = base::take(_lastMessage);
+	const auto oldChatListMessage = base::take(_chatListMessage);
 	for (const auto channel : add) {
-		_lastMessage = std::nullopt;
+		_chatListMessage = std::nullopt;
 		channel->setFeed(this);
 	}
-	_lastMessage = oldLastMessage;
+	_chatListMessage = oldChatListMessage;
 }
 
-bool Feed::justUpdateLastMessage(not_null<HistoryItem*> item) {
+bool Feed::justUpdateChatListMessage(not_null<HistoryItem*> item) {
-	if (!_lastMessage) {
+	if (!_chatListMessage) {
 		return false;
-	} else if (*_lastMessage
+	} else if (*_chatListMessage
-		&& item->position() <= (*_lastMessage)->position()) {
+		&& item->position() <= (*_chatListMessage)->position()) {
 		return false;
 	}
-	_lastMessage = item;
+	_chatListMessage = item;
 	return true;
 }
 
 void Feed::messageRemoved(not_null<HistoryItem*> item) {
-	if (lastMessage() == item) {
+	if (chatListMessage() == item) {
-		recountLastMessage();
+		recountChatListMessage();
 	}
 }
 
 void Feed::historyCleared(not_null<History*> history) {
-	if (const auto last = lastMessage()) {
+	if (const auto last = chatListMessage()) {
 		if (last->history() == history) {
 			messageRemoved(last);
 		}
 	}
 }
 
-void Feed::recountLastMessage() {
+void Feed::requestChatListMessage() {
-	_lastMessage = std::nullopt;
+	if (!chatListMessageKnown()) {
+		session().api().requestDialogEntry(this);
+	}
+}
+
+void Feed::recountChatListMessage() {
+	_chatListMessage = std::nullopt;
 	for (const auto history : _channels) {
-		if (!history->lastMessageKnown()) {
+		if (!history->chatListMessageKnown()) {
-			_parent->session().api().requestDialogEntry(this);
+			requestChatListMessage();
 			return;
 		}
 	}
-	setLastMessageFromChannels();
+	setChatListMessageFromChannels();
 }
 
-void Feed::setLastMessageFromChannels() {
+void Feed::setChatListMessageFromChannels() {
-	_lastMessage = nullptr;
+	_chatListMessage = nullptr;
 	for (const auto history : _channels) {
-		if (const auto last = history->lastMessage()) {
+		if (const auto last = history->chatListMessage()) {
-			justUpdateLastMessage(last);
+			justUpdateChatListMessage(last);
 		}
 	}
-	updateChatsListDate();
+	updateChatListDate();
 }
 
-void Feed::updateChatsListDate() {
+void Feed::updateChatListDate() {
-	if (_lastMessage && *_lastMessage) {
+	if (_chatListMessage && *_chatListMessage) {
-		setChatsListTimeId((*_lastMessage)->date());
+		setChatListTimeId((*_chatListMessage)->date());
 	}
 }
 
-HistoryItem *Feed::lastMessage() const {
-	return _lastMessage ? *_lastMessage : nullptr;
-}
-
-bool Feed::lastMessageKnown() const {
-	return !!_lastMessage;
-}
-
 int Feed::unreadCount() const {
 	return _unreadCount ? *_unreadCount : 0;
 }
@@ -341,17 +347,17 @@ bool Feed::unreadCountKnown() const {
 //		addChannel(channelId.v);
 //	}
 //
-//	_lastMessage = nullptr;
+//	_chatListMessage = nullptr;
 //	if (const auto peerId = peerFromMTP(data.vpeer)) {
 //		if (const auto channelId = peerToChannel(peerId)) {
 //			addChannel(channelId);
 //			const auto fullId = FullMsgId(channelId, data.vtop_message.v);
 //			if (const auto item = App::histItemById(fullId)) {
-//				justUpdateLastMessage(item);
+//				justUpdateChatListMessage(item);
 //			}
 //		}
 //	}
-//	updateChatsListDate();
+//	updateChatListDate();
 //
 //	setUnreadCounts(
 //		data.vunread_count.v,
@@ -493,19 +499,23 @@ bool Feed::chatListMutedBadge() const {
 	return _unreadCount ? (*_unreadCount <= _unreadMutedCount) : false;
 }
 
-HistoryItem *Feed::chatsListItem() const {
+HistoryItem *Feed::chatListMessage() const {
-	return lastMessage();
+	return _chatListMessage ? *_chatListMessage : nullptr;
 }
 
-const QString &Feed::chatsListName() const {
+bool Feed::chatListMessageKnown() const {
+	return _chatListMessage.has_value();
+}
+
+const QString &Feed::chatListName() const {
 	return _name;
 }
 
-const base::flat_set<QString> &Feed::chatsListNameWords() const {
+const base::flat_set<QString> &Feed::chatListNameWords() const {
 	return _nameWords;
 }
 
-const base::flat_set<QChar> &Feed::chatsListFirstLetters() const {
+const base::flat_set<QChar> &Feed::chatListFirstLetters() const {
 	return _nameFirstLetters;
 }
 

Telegram/SourceFiles/data/data_feed.h

@@ -11,6 +11,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "data/data_messages.h"
 
 class ChannelData;
+class AuthSession;
 
 namespace Data {
 
@@ -34,13 +35,18 @@ public:
 	static constexpr auto kId = 1;
 	static constexpr auto kChannelsLimit = 1000;
 
-	Feed(FeedId id, not_null<Data::Session*> parent);
+	Feed(not_null<Data::Session*> owner, FeedId id);
+	Feed(const Feed &) = delete;
+	Feed &operator=(const Feed &) = delete;
+
+	Data::Session &owner() const;
+	AuthSession &session() const;
 
 	FeedId id() const;
 	void registerOne(not_null<ChannelData*> channel);
 	void unregisterOne(not_null<ChannelData*> channel);
 
-	void updateLastMessage(not_null<HistoryItem*> item);
+	void updateChatListMessage(not_null<HistoryItem*> item);
 	void messageRemoved(not_null<HistoryItem*> item);
 	void historyCleared(not_null<History*> history);
 
@@ -54,8 +60,6 @@ public:
 	MessagePosition unreadPosition() const;
 	rpl::producer<MessagePosition> unreadPositionChanges() const;
 
-	HistoryItem *lastMessage() const;
-	bool lastMessageKnown() const;
 	int unreadCount() const;
 	bool unreadCountKnown() const;
 
@@ -65,10 +69,12 @@ public:
 	int chatListUnreadCount() const override;
 	bool chatListUnreadMark() const override;
 	bool chatListMutedBadge() const override;
-	HistoryItem *chatsListItem() const override;
+	HistoryItem *chatListMessage() const override;
-	const QString &chatsListName() const override;
+	bool chatListMessageKnown() const override;
-	const base::flat_set<QString> &chatsListNameWords() const override;
+	void requestChatListMessage() override;
-	const base::flat_set<QChar> &chatsListFirstLetters() const override;
+	const QString &chatListName() const override;
+	const base::flat_set<QString> &chatListNameWords() const override;
+	const base::flat_set<QChar> &chatListFirstLetters() const override;
 	void changedInChatListHook(Dialogs::Mode list, bool added) override;
 
 	void loadUserpic() override;
@@ -86,10 +92,10 @@ public:
 
 private:
 	void indexNameParts();
-	void recountLastMessage();
+	void recountChatListMessage();
-	void setLastMessageFromChannels();
+	void setChatListMessageFromChannels();
-	bool justUpdateLastMessage(not_null<HistoryItem*> item);
+	bool justUpdateChatListMessage(not_null<HistoryItem*> item);
-	void updateChatsListDate();
+	void updateChatListDate();
 	void changeChannelsList(
 		const std::vector<not_null<ChannelData*>> &add,
 		const std::vector<not_null<ChannelData*>> &remove);
@@ -98,7 +104,7 @@ private:
 	void updateUnreadCounts(PerformUpdate &&performUpdate);
 
 	FeedId _id = 0;
-	not_null<Data::Session*> _parent;
+	not_null<Data::Session*> _owner;
 	std::vector<not_null<History*>> _channels;
 	bool _settingChannels = false;
 	bool _channelsLoaded = false;
@@ -106,7 +112,7 @@ private:
 	QString _name;
 	base::flat_set<QString> _nameWords;
 	base::flat_set<QChar> _nameFirstLetters;
-	std::optional<HistoryItem*> _lastMessage;
+	std::optional<HistoryItem*> _chatListMessage;
 
 	rpl::variable<MessagePosition> _unreadPosition;
 	std::optional<int> _unreadCount;

Telegram/SourceFiles/data/data_media_types.cpp

@@ -187,7 +187,7 @@ bool Media::canBeGrouped() const {
 	return false;
 }
 
-QString Media::chatsListText() const {
+QString Media::chatListText() const {
 	auto result = notificationText();
 	return result.isEmpty()
 		? QString()
@@ -304,7 +304,7 @@ QString MediaPhoto::notificationText() const {
 	//return WithCaptionNotificationText(lang(lng_in_dlg_album), _caption);
 }
 
-QString MediaPhoto::chatsListText() const {
+QString MediaPhoto::chatListText() const {
 	return WithCaptionDialogsText(
 		lang(lng_in_dlg_photo),
 		parent()->originalText().text);
@@ -539,9 +539,9 @@ Image *MediaFile::replyPreview() const {
 	return _document->getReplyPreview(parent()->fullId());
 }
 
-QString MediaFile::chatsListText() const {
+QString MediaFile::chatListText() const {
 	if (const auto sticker = _document->sticker()) {
-		return Media::chatsListText();
+		return Media::chatListText();
 	}
 	const auto type = [&] {
 		if (_document->isVideoMessage()) {
@@ -861,7 +861,7 @@ LocationData *MediaLocation::location() const {
 	return _location;
 }
 
-QString MediaLocation::chatsListText() const {
+QString MediaLocation::chatListText() const {
 	return WithCaptionDialogsText(lang(lng_maps_point), _title);
 }
 
@@ -1032,7 +1032,7 @@ Image *MediaWebPage::replyPreview() const {
 	return nullptr;
 }
 
-QString MediaWebPage::chatsListText() const {
+QString MediaWebPage::chatListText() const {
 	return notificationText();
 }
 

Telegram/SourceFiles/data/data_media_types.h

@@ -86,7 +86,7 @@ public:
 	virtual Image *replyPreview() const;
 	// Returns text with link-start and link-end commands for service-color highlighting.
 	// Example: "[link1-start]You:[link1-end] [link1-start]Photo,[link1-end] caption text"
-	virtual QString chatsListText() const;
+	virtual QString chatListText() const;
 	virtual QString notificationText() const = 0;
 	virtual QString pinnedTextSubstring() const = 0;
 	virtual TextWithEntities clipboardText() const = 0;
@@ -136,7 +136,7 @@ public:
 	bool canBeGrouped() const override;
 	bool hasReplyPreview() const override;
 	Image *replyPreview() const override;
-	QString chatsListText() const override;
+	QString chatListText() const override;
 	QString notificationText() const override;
 	QString pinnedTextSubstring() const override;
 	TextWithEntities clipboardText() const override;
@@ -171,7 +171,7 @@ public:
 	bool canBeGrouped() const override;
 	bool hasReplyPreview() const override;
 	Image *replyPreview() const override;
-	QString chatsListText() const override;
+	QString chatListText() const override;
 	QString notificationText() const override;
 	QString pinnedTextSubstring() const override;
 	TextWithEntities clipboardText() const override;
@@ -233,7 +233,7 @@ public:
 	std::unique_ptr<Media> clone(not_null<HistoryItem*> parent) override;
 
 	LocationData *location() const override;
-	QString chatsListText() const override;
+	QString chatListText() const override;
 	QString notificationText() const override;
 	QString pinnedTextSubstring() const override;
 	TextWithEntities clipboardText() const override;
@@ -296,7 +296,7 @@ public:
 
 	bool hasReplyPreview() const override;
 	Image *replyPreview() const override;
-	QString chatsListText() const override;
+	QString chatListText() const override;
 	QString notificationText() const override;
 	QString pinnedTextSubstring() const override;
 	TextWithEntities clipboardText() const override;

Telegram/SourceFiles/data/data_session.cpp

@@ -2759,7 +2759,7 @@ not_null<Feed*> Session::feed(FeedId id) {
 	}
 	const auto [it, ok] = _feeds.emplace(
 		id,
-		std::make_unique<Feed>(id, this));
+		std::make_unique<Feed>(this, id));
 	return it->second.get();
 }
 
@@ -3038,9 +3038,7 @@ void Session::setProxyPromoted(PeerData *promoted) {
 		if (_proxyPromoted) {
 			const auto history = this->history(_proxyPromoted);
 			history->cacheProxyPromoted(true);
-			if (!history->lastMessageKnown()) {
+			history->requestChatListMessage();
-				_session->api().requestDialogEntry(history);
-			}
 			Notify::peerUpdatedDelayed(
 				_proxyPromoted,
 				Notify::PeerUpdate::Flag::ChannelPromotedChanged);

Telegram/SourceFiles/dialogs/dialogs_entry.cpp

@@ -102,7 +102,7 @@ void Entry::setChatListExistence(bool exists) {
 }
 
 TimeId Entry::adjustChatListTimeId() const {
-	return chatsListTimeId();
+	return chatListTimeId();
 }
 
 void Entry::changedInChatListHook(Dialogs::Mode list, bool added) {
@@ -135,13 +135,13 @@ PositionChange Entry::adjustByPosInChatList(
 	return { movedFrom, movedTo };
 }
 
-void Entry::setChatsListTimeId(TimeId date) {
+void Entry::setChatListTimeId(TimeId date) {
-	if (_lastMessageTimeId && _lastMessageTimeId >= date) {
+	if (_timeId && _timeId >= date) {
 		if (!inChatList(Dialogs::Mode::All)) {
 			return;
 		}
 	}
-	_lastMessageTimeId = date;
+	_timeId = date;
 	updateChatListSortPosition();
 }
 

Telegram/SourceFiles/dialogs/dialogs_entry.h

@@ -65,7 +65,7 @@ public:
 		return _sortKeyInChatList;
 	}
 	void updateChatListSortPosition();
-	void setChatsListTimeId(TimeId date);
+	void setChatListTimeId(TimeId date);
 	virtual void updateChatListExistence();
 	bool needUpdateInChatList() const;
 
@@ -74,10 +74,12 @@ public:
 	virtual int chatListUnreadCount() const = 0;
 	virtual bool chatListUnreadMark() const = 0;
 	virtual bool chatListMutedBadge() const = 0;
-	virtual HistoryItem *chatsListItem() const = 0;
+	virtual HistoryItem *chatListMessage() const = 0;
-	virtual const QString &chatsListName() const = 0;
+	virtual bool chatListMessageKnown() const = 0;
-	virtual const base::flat_set<QString> &chatsListNameWords() const = 0;
+	virtual void requestChatListMessage() = 0;
-	virtual const base::flat_set<QChar> &chatsListFirstLetters() const = 0;
+	virtual const QString &chatListName() const = 0;
+	virtual const base::flat_set<QString> &chatListNameWords() const = 0;
+	virtual const base::flat_set<QChar> &chatListFirstLetters() const = 0;
 
 	virtual void loadUserpic() = 0;
 	virtual void paintUserpic(
@@ -94,8 +96,8 @@ public:
 		paintUserpic(p, rtl() ? (w - x - size) : x, y, size);
 	}
 
-	TimeId chatsListTimeId() const {
+	TimeId chatListTimeId() const {
-		return _lastMessageTimeId;
+		return _timeId;
 	}
 
 	virtual ~Entry() = default;
@@ -118,7 +120,7 @@ private:
 	uint64 _sortKeyInChatList = 0;
 	int _pinnedIndex = 0;
 	bool _isProxyPromoted = false;
-	TimeId _lastMessageTimeId = 0;
+	TimeId _timeId = 0;
 
 };
 

Telegram/SourceFiles/dialogs/dialogs_indexed_list.cpp

@@ -23,7 +23,7 @@ RowsByLetter IndexedList::addToEnd(Key key) {
 	RowsByLetter result;
 	if (!_list.contains(key)) {
 		result.emplace(0, _list.addToEnd(key));
-		for (auto ch : key.entry()->chatsListFirstLetters()) {
+		for (const auto ch : key.entry()->chatListFirstLetters()) {
 			auto j = _index.find(ch);
 			if (j == _index.cend()) {
 				j = _index.emplace(
@@ -42,7 +42,7 @@ Row *IndexedList::addByName(Key key) {
 	}
 
 	Row *result = _list.addByName(key);
-	for (auto ch : key.entry()->chatsListFirstLetters()) {
+	for (const auto ch : key.entry()->chatListFirstLetters()) {
 		auto j = _index.find(ch);
 		if (j == _index.cend()) {
 			j = _index.emplace(
@@ -68,7 +68,7 @@ void IndexedList::adjustByPos(const RowsByLetter &links) {
 
 void IndexedList::moveToTop(Key key) {
 	if (_list.moveToTop(key)) {
-		for (auto ch : key.entry()->chatsListFirstLetters()) {
+		for (const auto ch : key.entry()->chatListFirstLetters()) {
 			if (auto it = _index.find(ch); it != _index.cend()) {
 				it->second->moveToTop(key);
 			}
@@ -123,7 +123,7 @@ void IndexedList::adjustByName(
 
 	auto toRemove = oldLetters;
 	auto toAdd = base::flat_set<QChar>();
-	for (auto ch : key.entry()->chatsListFirstLetters()) {
+	for (const auto ch : key.entry()->chatListFirstLetters()) {
 		auto j = toRemove.find(ch);
 		if (j == toRemove.cend()) {
 			toAdd.insert(ch);
@@ -162,7 +162,7 @@ void IndexedList::adjustNames(
 
 	auto toRemove = oldLetters;
 	auto toAdd = base::flat_set<QChar>();
-	for (auto ch : key.entry()->chatsListFirstLetters()) {
+	for (const auto ch : key.entry()->chatListFirstLetters()) {
 		auto j = toRemove.find(ch);
 		if (j == toRemove.cend()) {
 			toAdd.insert(ch);
@@ -194,7 +194,7 @@ void IndexedList::adjustNames(
 
 void IndexedList::del(Key key, Row *replacedBy) {
 	if (_list.del(key, replacedBy)) {
-		for (auto ch : key.entry()->chatsListFirstLetters()) {
+		for (const auto ch : key.entry()->chatListFirstLetters()) {
 			if (auto it = _index.find(ch); it != _index.cend()) {
 				it->second->del(key, replacedBy);
 			}

Telegram/SourceFiles/dialogs/dialogs_inner_widget.cpp

@@ -1702,7 +1702,7 @@ void DialogsInner::applyFilterUpdate(QString newFilter, bool force) {
 					+ (toFilterContacts ? toFilterContacts->size() : 0));
 				if (toFilter) {
 					for (const auto row : *toFilter) {
-						const auto &nameWords = row->entry()->chatsListNameWords();
+						const auto &nameWords = row->entry()->chatListNameWords();
 						auto nb = nameWords.cbegin(), ne = nameWords.cend(), ni = nb;
 						for (fi = fb; fi != fe; ++fi) {
 							auto filterWord = *fi;
@@ -1722,7 +1722,7 @@ void DialogsInner::applyFilterUpdate(QString newFilter, bool force) {
 				}
 				if (toFilterContacts) {
 					for (const auto row : *toFilterContacts) {
-						const auto &nameWords = row->entry()->chatsListNameWords();
+						const auto &nameWords = row->entry()->chatListNameWords();
 						auto nb = nameWords.cbegin(), ne = nameWords.cend(), ni = nb;
 						for (fi = fb; fi != fe; ++fi) {
 							auto filterWord = *fi;
@@ -1875,7 +1875,7 @@ void DialogsInner::applyDialog(const MTPDdialog &dialog) {
 	history->applyDialog(dialog);
 
 	if (!history->useProxyPromotion() && !history->isPinnedDialog()) {
-		const auto date = history->chatsListTimeId();
+		const auto date = history->chatListTimeId();
 		if (date != 0) {
 			addSavedPeersAfter(ParseDateTime(date));
 		}
@@ -1898,7 +1898,7 @@ void DialogsInner::applyDialog(const MTPDdialog &dialog) {
 //	feed->applyDialog(dialog);
 //
 //	if (!feed->useProxyPromotion() && !feed->isPinnedDialog()) {
-//		const auto date = feed->chatsListDate();
+//		const auto date = feed->chatListDate();
 //		if (!date.isNull()) {
 //			addSavedPeersAfter(date);
 //		}
@@ -1913,7 +1913,7 @@ void DialogsInner::addSavedPeersAfter(const QDateTime &date) {
 		saved.remove(lastDate, lastPeer);
 
 		const auto history = App::history(lastPeer);
-		history->setChatsListTimeId(ServerTimeFromParsed(lastDate));
+		history->setChatListTimeId(ServerTimeFromParsed(lastDate));
 		_contactsNoDialogs->del(history);
 	}
 }
@@ -2233,7 +2233,7 @@ void DialogsInner::refreshSearchInChatLabel() {
 			}
 			return peer->name;
 		} else if (const auto feed = _searchInChat.feed()) {
-			return feed->chatsListName();
+			return feed->chatListName();
 		}
 		return QString();
 	}();

Telegram/SourceFiles/dialogs/dialogs_layout.cpp

@@ -377,7 +377,7 @@ void paintRow(
 		from->dialogName().drawElided(p, rectForName.left(), rectForName.top(), rectForName.width());
 	} else {
 		p.setFont(st::msgNameFont);
-		auto text = entry->chatsListName(); // TODO feed name with emoji
+		auto text = entry->chatListName(); // TODO feed name with emoji
 		auto textWidth = st::msgNameFont->width(text);
 		if (textWidth > rectForName.width()) {
 			text = st::msgNameFont->elided(text, rectForName.width());
@@ -528,7 +528,7 @@ void RowPainter::paint(
 	const auto unreadCount = entry->chatListUnreadCount();
 	const auto unreadMark = entry->chatListUnreadMark();
 	const auto unreadMuted = entry->chatListMutedBadge();
-	const auto item = entry->chatsListItem();
+	const auto item = entry->chatListMessage();
 	const auto cloudDraft = [&]() -> const Data::Draft*{
 		if (history && (!item || (!unreadCount && !unreadMark))) {
 			// Draw item, if there are unread messages.

Telegram/SourceFiles/dialogs/dialogs_list.cpp

@@ -114,15 +114,15 @@ Row *List::adjustByName(Key key) {
 	if (i == _rowByKey.cend()) return nullptr;
 
 	const auto row = i->second;
-	const auto name = key.entry()->chatsListName();
+	const auto name = key.entry()->chatListName();
 	auto change = row;
 	while (change->_prev
-		&& change->_prev->entry()->chatsListName().compare(name, Qt::CaseInsensitive) < 0) {
+		&& change->_prev->entry()->chatListName().compare(name, Qt::CaseInsensitive) < 0) {
 		change = change->_prev;
 	}
 	if (!insertBefore(row, change)) {
 		while (change->_next != _end
-			&& change->_next->entry()->chatsListName().compare(name, Qt::CaseInsensitive) < 0) {
+			&& change->_next->entry()->chatListName().compare(name, Qt::CaseInsensitive) < 0) {
 			change = change->_next;
 		}
 		insertAfter(row, change);
@@ -137,14 +137,14 @@ Row *List::addByName(Key key) {
 
 	const auto row = addToEnd(key);
 	auto change = row;
-	const auto name = key.entry()->chatsListName();
+	const auto name = key.entry()->chatListName();
 	while (change->_prev
-		&& change->_prev->entry()->chatsListName().compare(name, Qt::CaseInsensitive) > 0) {
+		&& change->_prev->entry()->chatListName().compare(name, Qt::CaseInsensitive) > 0) {
 		change = change->_prev;
 	}
 	if (!insertBefore(row, change)) {
 		while (change->_next != _end
-			&& change->_next->entry()->chatsListName().compare(name, Qt::CaseInsensitive) < 0) {
+			&& change->_next->entry()->chatListName().compare(name, Qt::CaseInsensitive) < 0) {
 			change = change->_next;
 		}
 		insertAfter(row, change);

Telegram/SourceFiles/history/admin_log/history_admin_log_inner.cpp

@@ -716,7 +716,7 @@ int InnerWidget::resizeGetHeight(int newWidth) {
 
 	const auto resizeAllItems = (_itemsWidth != newWidth);
 	auto newHeight = 0;
-	for (auto &item : base::reversed(_items)) {
+	for (const auto &item : ranges::view::reverse(_items)) {
 		item->setY(newHeight);
 		if (item->pendingResize() || resizeAllItems) {
 			newHeight += item->resizeGetHeight(newWidth);

Telegram/SourceFiles/history/history.cpp

@@ -60,9 +60,9 @@ constexpr auto kSkipCloudDraftsFor = TimeId(3);
 
 } // namespace
 
-History::History(not_null<Data::Session*> owner, const PeerId &peerId)
+History::History(not_null<Data::Session*> owner, PeerId peerId)
 : Entry(this)
-, peer(App::peer(peerId))
+, peer(owner->peer(peerId))
 , cloudDraftTextCache(st::dialogsTextWidthMin)
 , _owner(owner)
 , _mute(_owner->notifyIsMuted(peer))
@@ -138,15 +138,31 @@ void History::itemRemoved(not_null<HistoryItem*> item) {
 				setLastMessage(last);
 			}
 		}
-		if (const auto channel = peer->asChannel()) {
+	}
-			if (const auto feed = channel->feed()) {
+	checkChatListMessageRemoved(item);
-				// Must be after history->lastMessage() is updated.
+	itemVanished(item);
-				// Otherwise feed last message will be this value again.
+	if (const auto chat = peer->asChat()) {
-				feed->messageRemoved(item);
+		if (const auto to = chat->getMigrateToChannel()) {
+			if (const auto history = owner().historyLoaded(to)) {
+				history->checkChatListMessageRemoved(item);
 			}
 		}
 	}
-	itemVanished(item);
+}
+
+void History::checkChatListMessageRemoved(not_null<HistoryItem*> item) {
+	if (chatListMessage() != item) {
+		return;
+	}
+	_chatListMessage = std::nullopt;
+	refreshChatListMessage();
+	if (const auto channel = peer->asChannel()) {
+		if (const auto feed = channel->feed()) {
+			// Must be after history->chatListMessage() is updated.
+			// Otherwise feed last message will be this value again.
+			feed->messageRemoved(item);
+		}
+	}
 }
 
 void History::itemVanished(not_null<HistoryItem*> item) {
@@ -1130,7 +1146,7 @@ void History::newItemAdded(not_null<HistoryItem*> item) {
 			notifies.push_back(item);
 			App::main()->newUnreadMsg(this, item);
 		}
-	} else if (!item->isGroupMigrate() || !peer->isMegagroup()) {
+	} else {
 		inboxRead(item);
 	}
 }
@@ -1285,7 +1301,7 @@ void History::addItemsToLists(
 		// lastParticipants are displayed in Profile as members list.
 		markupSenders = &peer->asChannel()->mgInfo->markupSenders;
 	}
-	for (const auto item : base::reversed(items)) {
+	for (const auto item : ranges::view::reverse(items)) {
 		item->addToUnreadMentions(UnreadMentionType::Existing);
 		if (item->from()->id) {
 			if (lastAuthors) { // chats
@@ -1465,7 +1481,7 @@ void History::inboxRead(not_null<const HistoryItem*> wasRead) {
 
 void History::outboxRead(MsgId upTo) {
 	setOutboxReadTill(upTo);
-	if (const auto last = lastMessage()) {
+	if (const auto last = chatListMessage()) {
 		if (last->out() && IsServerMsgId(last->id) && last->id <= upTo) {
 			if (const auto main = App::main()) {
 				main->repaintDialogRow({ this, last->fullId() });
@@ -1701,7 +1717,7 @@ std::shared_ptr<AdminLog::LocalIdManager> History::adminLogIdManager() {
 }
 
 TimeId History::adjustChatListTimeId() const {
-	const auto result = chatsListTimeId();
+	const auto result = chatListTimeId();
 	if (const auto draft = cloudDraft()) {
 		if (!Data::draftIsNull(draft) && !session().supportMode()) {
 			return std::max(result, draft->date);
@@ -1889,19 +1905,23 @@ bool History::chatListMutedBadge() const {
 	return mute();
 }
 
-HistoryItem *History::chatsListItem() const {
+HistoryItem *History::chatListMessage() const {
-	return lastMessage();
+	return _chatListMessage.value_or(nullptr);
 }
 
-const QString &History::chatsListName() const {
+bool History::chatListMessageKnown() const {
+	return _chatListMessage.has_value();
+}
+
+const QString &History::chatListName() const {
 	return peer->name;
 }
 
-const base::flat_set<QString> &History::chatsListNameWords() const {
+const base::flat_set<QString> &History::chatListNameWords() const {
 	return peer->nameWords();
 }
 
-const base::flat_set<QChar> &History::chatsListFirstLetters() const {
+const base::flat_set<QChar> &History::chatListFirstLetters() const {
 	return peer->nameFirstLetters();
 }
 
@@ -2050,40 +2070,194 @@ void History::markFullyLoaded() {
 }
 
 void History::setLastMessage(HistoryItem *item) {
-	if (item) {
+	if (_lastMessage && *_lastMessage == item) {
-		if (_lastMessage) {
+		return;
-			if (!*_lastMessage) {
+	}
-				Local::removeSavedPeer(peer);
+	_lastMessage = item;
-			} else if (!IsServerMsgId((*_lastMessage)->id)
+	_chatListMessage = std::nullopt;
-				&& (*_lastMessage)->date() > item->date()) {
+	if (!peer->migrateTo()) {
-				return;
+		// We don't want to request last message for all deactivated chats.
-			}
+		// This is a heavy request for them, because we need to get last
-		}
+		// two items by messages.getHistory to skip the migration message.
-		_lastMessage = item;
+		requestChatListMessage();
-		if (const auto feed = peer->feed()) {
-			feed->updateLastMessage(item);
-		}
-		setChatsListTimeId(item->date());
-	} else if (!_lastMessage || *_lastMessage) {
-		_lastMessage = nullptr;
-		updateChatListEntry();
 	}
 }
 
+void History::refreshChatListMessage() {
+	const auto known = chatListMessageKnown();
+	setChatListMessageFromLast();
+	if (known && !_chatListMessage) {
+		requestChatListMessage();
+	}
+}
+
+void History::setChatListMessage(HistoryItem *item) {
+	if (_chatListMessage && *_chatListMessage == item) {
+		return;
+	}
+	if (item) {
+		if (_chatListMessage) {
+			if (!*_chatListMessage) {
+				Local::removeSavedPeer(peer);
+			} else if (!IsServerMsgId((*_chatListMessage)->id)
+				&& (*_chatListMessage)->date() > item->date()) {
+				return;
+			}
+		}
+		_chatListMessage = item;
+		setChatListTimeId(item->date());
+	} else if (!_chatListMessage || *_chatListMessage) {
+		_chatListMessage = nullptr;
+		updateChatListEntry();
+	}
+	if (const auto to = peer->migrateTo()) {
+		if (const auto history = owner().historyLoaded(to)) {
+			if (!history->chatListMessageKnown()) {
+				history->requestChatListMessage();
+			}
+		}
+	}
+}
+
+auto History::computeChatListMessageFromLast() const
+-> std::optional<HistoryItem*> {
+	if (!_lastMessage) {
+		return _lastMessage;
+	}
+
+	// In migrated groups we want to skip essential message
+	// about migration in the chats list and display the last
+	// non-migration message from the original legacy group.
+	const auto last = lastMessage();
+	if (!last || !last->isGroupEssential() || !last->isEmpty()) {
+		return _lastMessage;
+	}
+	if (const auto chat = peer->asChat()) {
+		// In chats we try to take the item before the 'last', which
+		// is the empty-displayed migration message.
+		if (!loadedAtBottom()) {
+			// We don't know the tail of the history.
+			return std::nullopt;
+		}
+		const auto before = [&]() -> HistoryItem* {
+			for (const auto &block : ranges::view::reverse(blocks)) {
+				const auto &messages = block->messages;
+				for (const auto &item : ranges::view::reverse(messages)) {
+					if (item->data() != last) {
+						return item->data();
+					}
+				}
+			}
+			return nullptr;
+		}();
+		if (before) {
+			// We found a message that is not the migration one.
+			return before;
+		} else if (loadedAtTop()) {
+			// No other messages in this history.
+			return _lastMessage;
+		}
+		return std::nullopt;
+	} else if (const auto from = migrateFrom()) {
+		// In megagroups we just try to use
+		// the message from the original group.
+		return from->chatListMessageKnown()
+			? std::make_optional(from->chatListMessage())
+			: std::nullopt;
+	}
+	return _lastMessage;
+}
+
+void History::setChatListMessageFromLast() {
+	if (const auto good = computeChatListMessageFromLast()) {
+		setChatListMessage(*good);
+	} else {
+		_chatListMessage = std::nullopt;
+	}
+}
+
+void History::requestChatListMessage() {
+	if (!lastMessageKnown()) {
+		session().api().requestDialogEntry(this);
+		return;
+	} else if (chatListMessageKnown()) {
+		return;
+	}
+	setChatListMessageFromLast();
+	if (!chatListMessageKnown()) {
+		setFakeChatListMessage();
+	}
+}
+
+void History::setFakeChatListMessage() {
+	if (const auto chat = peer->asChat()) {
+		// In chats we try to take the item before the 'last', which
+		// is the empty-displayed migration message.
+		session().api().requestFakeChatListMessage(this);
+	} else if (const auto from = migrateFrom()) {
+		// In megagroups we just try to use
+		// the message from the original group.
+		from->requestChatListMessage();
+	}
+}
+
+void History::setFakeChatListMessageFrom(const MTPmessages_Messages &data) {
+	if (!lastMessageKnown()) {
+		requestChatListMessage();
+		return;
+	}
+	const auto finalize = gsl::finally([&] {
+		// Make sure that we have chatListMessage when we get out of here.
+		if (!chatListMessageKnown()) {
+			setChatListMessage(lastMessage());
+		}
+	});
+	const auto last = lastMessage();
+	if (!last || !last->isGroupEssential() || !last->isEmpty()) {
+		// Last message is good enough.
+		return;
+	}
+	const auto other = data.match([&](
+			const MTPDmessages_messagesNotModified &) {
+		return static_cast<const MTPMessage*>(nullptr);
+	}, [&](const auto &data) {
+		for (const auto &message : data.vmessages.v) {
+			const auto id = message.match([](const auto &data) {
+				return data.vid.v;
+			});
+			if (id != last->id) {
+				return &message;
+			}
+		}
+		return static_cast<const MTPMessage*>(nullptr);
+	});
+	if (!other) {
+		// Other (non equal to the last one) message not found.
+		return;
+	}
+	const auto item = owner().addNewMessage(*other, NewMessageExisting);
+	if (!item || (item->isGroupEssential() && item->isEmpty())) {
+		// Not better than the last one.
+		return;
+	}
+	setChatListMessage(item);
+}
+
 HistoryItem *History::lastMessage() const {
-	return _lastMessage ? (*_lastMessage) : nullptr;
+	return _lastMessage.value_or(nullptr);
 }
 
 bool History::lastMessageKnown() const {
-	return !!_lastMessage;
+	return _lastMessage.has_value();
 }
 
 void History::updateChatListExistence() {
 	Entry::updateChatListExistence();
-	if (!lastMessageKnown() || !unreadCountKnown()) {
+	if (const auto channel = peer->asChannel()) {
-		if (const auto channel = peer->asChannel()) {
+		if (!channel->feed()) {
-			if (!channel->feed()) {
+			// After ungrouping from a feed we need to load dialog.
-				// After ungrouping from a feed we need to load dialog.
+			requestChatListMessage();
+			if (!unreadCountKnown()) {
 				session().api().requestDialogEntry(this);
 			}
 		}
@@ -2164,6 +2338,51 @@ void History::applyDialog(const MTPDdialog &data) {
 	}
 }
 
+void History::dialogEntryApplied() {
+	if (!lastMessageKnown()) {
+		setLastMessage(nullptr);
+	}
+	if (!chatListMessageKnown()) {
+		requestChatListMessage();
+		return;
+	}
+	if (!chatListMessage()) {
+		if (const auto chat = peer->asChat()) {
+			if (!chat->haveLeft()) {
+				Local::addSavedPeer(
+					peer,
+					ParseDateTime(chatListTimeId()));
+			}
+		} else if (const auto channel = peer->asChannel()) {
+			const auto inviter = channel->inviter;
+			if (inviter != 0 && channel->amIn()) {
+				if (const auto from = App::userLoaded(inviter)) {
+					unloadBlocks();
+					addNewerSlice(QVector<MTPMessage>());
+					insertJoinedMessage(true);
+				}
+			}
+		} else {
+			App::main()->deleteConversation(peer, false);
+		}
+		return;
+	}
+
+	if (chatListTimeId() != 0 && loadedAtBottom()) {
+		if (const auto channel = peer->asChannel()) {
+			const auto inviter = channel->inviter;
+			if (inviter != 0
+				&& chatListTimeId() <= channel->inviteDate
+				&& channel->amIn()) {
+				if (const auto from = App::userLoaded(inviter)) {
+					insertJoinedMessage(true);
+				}
+			}
+		}
+	}
+	updateChatListExistence();
+}
+
 bool History::clearUnreadOnClientSide() const {
 	if (!session().supportMode()) {
 		return false;
@@ -2253,8 +2472,8 @@ MsgId History::minMsgId() const {
 }
 
 MsgId History::maxMsgId() const {
-	for (const auto &block : base::reversed(blocks)) {
+	for (const auto &block : ranges::view::reverse(blocks)) {
-		for (const auto &message : base::reversed(block->messages)) {
+		for (const auto &message : ranges::view::reverse(block->messages)) {
 			const auto item = message->data();
 			if (IsServerMsgId(item->id)) {
 				return item->id;
@@ -2278,8 +2497,8 @@ HistoryItem *History::lastSentMessage() const {
 	if (!loadedAtBottom()) {
 		return nullptr;
 	}
-	for (const auto &block : base::reversed(blocks)) {
+	for (const auto &block : ranges::view::reverse(blocks)) {
-		for (const auto &message : base::reversed(block->messages)) {
+		for (const auto &message : ranges::view::reverse(block->messages)) {
 			const auto item = message->data();
 			// Skip if message is video message or sticker.
 			if (const auto media = item->media()) {
@@ -2336,7 +2555,7 @@ bool History::isMegagroup() const {
 }
 
 not_null<History*> History::migrateToOrMe() const {
-	if (auto to = peer->migrateTo()) {
+	if (const auto to = peer->migrateTo()) {
 		return App::history(to);
 	}
 	// We could get it by App::history(peer), but we optimize.
@@ -2344,7 +2563,7 @@ not_null<History*> History::migrateToOrMe() const {
 }
 
 History *History::migrateFrom() const {
-	if (auto from = peer->migrateFrom()) {
+	if (const auto from = peer->migrateFrom()) {
 		return App::history(from);
 	}
 	return nullptr;
@@ -2423,7 +2642,7 @@ HistoryService *History::insertJoinedMessage(bool unread) {
 			// Due to a server bug sometimes inviteDate is less (before) than the
 			// first message in the megagroup (message about migration), let us
 			// ignore that and think, that the inviteDate is always greater-or-equal.
-			if (item->isGroupMigrate()
+			if ((item->id == 1)
 				&& peer->isMegagroup()
 				&& peer->migrateFrom()) {
 				peer->asChannel()->mgInfo->joinedMessageFound = true;
@@ -2437,7 +2656,7 @@ HistoryService *History::insertJoinedMessage(bool unread) {
 					inviter,
 					flags);
 				addNewInTheMiddle(_joinedMessage, blockIndex, itemIndex);
-				const auto lastDate = chatsListTimeId();
+				const auto lastDate = chatListTimeId();
 				if (!lastDate || inviteDate >= lastDate) {
 					setLastMessage(_joinedMessage);
 					if (unread) {
@@ -2508,9 +2727,29 @@ bool History::isEmpty() const {
 }
 
 bool History::isDisplayedEmpty() const {
-	return isEmpty() || ((blocks.size() == 1)
+	return findFirstNonEmpty() == nullptr;
-		&& blocks.front()->messages.size() == 1
+}
-		&& blocks.front()->messages.front()->data()->isEmpty());
+
+auto History::findFirstNonEmpty() const -> Element* {
+	for (const auto &block : blocks) {
+		for (const auto &element : block->messages) {
+			if (!element->data()->isEmpty()) {
+				return element.get();
+			}
+		}
+	}
+	return nullptr;
+}
+
+auto History::findLastNonEmpty() const -> Element* {
+	for (const auto &block : ranges::view::reverse(blocks)) {
+		for (const auto &element : ranges::view::reverse(block->messages)) {
+			if (!element->data()->isEmpty()) {
+				return element.get();
+			}
+		}
+	}
+	return nullptr;
 }
 
 bool History::hasOrphanMediaGroupPart() const {
@@ -2624,9 +2863,7 @@ void History::clearUpTill(MsgId availableMinId) {
 		item->destroy();
 	} while (!isEmpty());
 
-	if (!lastMessageKnown()) {
+	requestChatListMessage();
-		session().api().requestDialogEntry(this);
-	}
 	_owner->sendHistoryChangeNotifications();
 }
 

Telegram/SourceFiles/history/history.h

@@ -58,7 +58,7 @@ class History final : public Dialogs::Entry {
 public:
 	using Element = HistoryView::Element;
 
-	History(not_null<Data::Session*> owner, const PeerId &peerId);
+	History(not_null<Data::Session*> owner, PeerId peerId);
 	History(const History &) = delete;
 	History &operator=(const History &) = delete;
 
@@ -77,6 +77,8 @@ public:
 
 	bool isEmpty() const;
 	bool isDisplayedEmpty() const;
+	Element *findFirstNonEmpty() const;
+	Element *findLastNonEmpty() const;
 	bool hasOrphanMediaGroupPart() const;
 	bool removeOrphanMediaGroupPart();
 	QVector<MsgId> collectMessagesFromUserToDelete(
@@ -192,6 +194,7 @@ public:
 		int unreadCount,
 		MsgId maxInboxRead,
 		MsgId maxOutboxRead);
+	void dialogEntryApplied();
 
 	MsgId minMsgId() const;
 	MsgId maxMsgId() const;
@@ -283,10 +286,12 @@ public:
 	int chatListUnreadCount() const override;
 	bool chatListUnreadMark() const override;
 	bool chatListMutedBadge() const override;
-	HistoryItem *chatsListItem() const override;
+	HistoryItem *chatListMessage() const override;
-	const QString &chatsListName() const override;
+	bool chatListMessageKnown() const override;
-	const base::flat_set<QString> &chatsListNameWords() const override;
+	void requestChatListMessage() override;
-	const base::flat_set<QChar> &chatsListFirstLetters() const override;
+	const QString &chatListName() const override;
+	const base::flat_set<QString> &chatListNameWords() const override;
+	const base::flat_set<QChar> &chatListFirstLetters() const override;
 	void loadUserpic() override;
 	void paintUserpic(
 		Painter &p,
@@ -294,6 +299,9 @@ public:
 		int y,
 		int size) const override;
 
+	void setFakeChatListMessageFrom(const MTPmessages_Messages &data);
+	void checkChatListMessageRemoved(not_null<HistoryItem*> item);
+
 	void forgetScrollState() {
 		scrollTopItem = nullptr;
 	}
@@ -411,6 +419,12 @@ private:
 	void checkLastMessage();
 	void setLastMessage(HistoryItem *item);
 
+	void refreshChatListMessage();
+	void setChatListMessage(HistoryItem *item);
+	std::optional<HistoryItem*> computeChatListMessageFromLast() const;
+	void setChatListMessageFromLast();
+	void setFakeChatListMessage();
+
 	// Add all items to the unread mentions if we were not loaded at bottom and now are.
 	void checkAddAllToUnreadMentions();
 
@@ -449,6 +463,12 @@ private:
 	std::optional<int> _unreadMentionsCount;
 	base::flat_set<MsgId> _unreadMentions;
 	std::optional<HistoryItem*> _lastMessage;
+
+	// This almost always is equal to _lastMessage. The only difference is
+	// for a group that migrated to a supergroup. Then _lastMessage can
+	// be a migrate message, but _chatListMessage should be the one before.
+	std::optional<HistoryItem*> _chatListMessage;
+
 	bool _unreadMark = false;
 
 	// A pointer to the block that is currently being built.

Telegram/SourceFiles/history/history_inner_widget.cpp

@@ -436,10 +436,6 @@ void HistoryInner::enumerateDates(Method method) {
 				if (itemtop > _visibleAreaTop) {
 					// Previous item (from the _migrated history) is drawing date now.
 					return false;
-				} else if (item == _history->blocks.front()->messages.front()->data() && item->isGroupMigrate()
-					&& _migrated->blocks.back()->messages.back()->data()->isGroupMigrate()) {
-					// This item is completely invisible and should be completely ignored.
-					return false;
 				}
 			}
 
@@ -1954,17 +1950,19 @@ void HistoryInner::recountHistoryGeometry() {
 		_migrated->resizeToWidth(_contentWidth);
 	}
 
-	// with migrated history we perhaps do not need to display first _history message
+	// With migrated history we perhaps do not need to display
-	// (if last _migrated message and first _history message are both isGroupMigrate)
+	// the first _history message date (just skip it by height).
-	// or at least we don't need to display first _history date (just skip it by height)
 	_historySkipHeight = 0;
-	if (_migrated) {
+	if (_migrated
-		if (!_migrated->isEmpty() && !_history->isEmpty() && _migrated->loadedAtBottom() && _history->loadedAtTop()) {
+		&& _migrated->loadedAtBottom()
-			if (_migrated->blocks.back()->messages.back()->dateTime().date() == _history->blocks.front()->messages.front()->dateTime().date()) {
+		&& _history->loadedAtTop()) {
-				if (_migrated->blocks.back()->messages.back()->data()->isGroupMigrate() && _history->blocks.front()->messages.front()->data()->isGroupMigrate()) {
+		if (const auto first = _history->findFirstNonEmpty()) {
-					_historySkipHeight += _history->blocks.front()->messages.front()->height();
+			if (const auto last = _migrated->findLastNonEmpty()) {
-				} else if (_migrated->height() > _history->blocks.front()->messages.front()->displayedDateHeight()) {
+				if (first->dateTime().date() == last->dateTime().date()) {
-					_historySkipHeight += _history->blocks.front()->messages.front()->displayedDateHeight();
+					const auto dateHeight = first->displayedDateHeight();
+					if (_migrated->height() > dateHeight) {
+						_historySkipHeight += dateHeight;
+					}
 				}
 			}
 		}

Telegram/SourceFiles/history/history_inner_widget.h

@@ -298,9 +298,8 @@ private:
 	int _contentWidth = 0;
 	int _historyPaddingTop = 0;
 
-	// with migrated history we perhaps do not need to display first _history message
+	// With migrated history we perhaps do not need to display
-	// (if last _migrated message and first _history message are both isGroupMigrate)
+	// the first _history message date (just skip it by height).
-	// or at least we don't need to display first _history date (just skip it by height)
 	int _historySkipHeight = 0;
 
 	std::unique_ptr<BotAbout> _botAbout;

Telegram/SourceFiles/history/history_item.cpp

@@ -176,12 +176,12 @@ TimeId HistoryItem::date() const {
 
 void HistoryItem::finishEdition(int oldKeyboardTop) {
 	_history->owner().requestItemViewRefresh(this);
-	invalidateChatsListEntry();
+	invalidateChatListEntry();
 	if (const auto group = _history->owner().groups().find(this)) {
 		const auto leader = group->items.back();
 		if (leader != this) {
 			_history->owner().requestItemViewRefresh(leader);
-			leader->invalidateChatsListEntry();
+			leader->invalidateChatListEntry();
 		}
 	}
 
@@ -217,7 +217,7 @@ ReplyKeyboard *HistoryItem::inlineReplyKeyboard() {
 	return nullptr;
 }
 
-void HistoryItem::invalidateChatsListEntry() {
+void HistoryItem::invalidateChatListEntry() {
 	if (const auto main = App::main()) {
 		// #TODO feeds search results
 		main->repaintDialogRow({ history(), fullId() });
@@ -462,7 +462,7 @@ bool HistoryItem::canDelete() const {
 	}
 	auto channel = _history->peer->asChannel();
 	if (!channel) {
-		return !(_flags & MTPDmessage_ClientFlag::f_is_group_migrate);
+		return !(_flags & MTPDmessage_ClientFlag::f_is_group_essential);
 	}
 
 	if (id == 1) {
@@ -706,7 +706,7 @@ QString HistoryItem::notificationText() const {
 QString HistoryItem::inDialogsText(DrawInDialog way) const {
 	auto getText = [this]() {
 		if (_media) {
-			return _media->chatsListText();
+			return _media->chatListText();
 		} else if (!emptyText()) {
 			return TextUtilities::Clean(_text.originalText());
 		}

Telegram/SourceFiles/history/history_item.h

@@ -134,8 +134,8 @@ public:
 	bool hasTextLinks() const {
 		return _flags & MTPDmessage_ClientFlag::f_has_text_links;
 	}
-	bool isGroupMigrate() const {
+	bool isGroupEssential() const {
-		return _flags & MTPDmessage_ClientFlag::f_is_group_migrate;
+		return _flags & MTPDmessage_ClientFlag::f_is_group_essential;
 	}
 	bool hasViews() const {
 		return _flags & MTPDmessage::Flag::f_views;
@@ -294,7 +294,7 @@ protected:
 	}
 	HistoryMessageReplyMarkup *inlineReplyMarkup();
 	ReplyKeyboard *inlineReplyKeyboard();
-	void invalidateChatsListEntry();
+	void invalidateChatListEntry();
 
 	void setGroupId(MessageGroupId groupId);
 

Telegram/SourceFiles/history/history_service.cpp

@@ -36,7 +36,7 @@ constexpr auto kPinnedMessageTextLimit = 16;
 
 void HistoryService::setMessageByAction(const MTPmessageAction &action) {
 	auto prepareChatAddUserText = [this](const MTPDmessageActionChatAddUser &action) {
-		auto result = PreparedText {};
+		auto result = PreparedText{};
 		auto &users = action.vusers.v;
 		if (users.size() == 1) {
 			auto u = App::user(peerFromUser(users[0]));
@@ -72,14 +72,14 @@ void HistoryService::setMessageByAction(const MTPmessageAction &action) {
 	};
 
 	auto prepareChatJoinedByLink = [this](const MTPDmessageActionChatJoinedByLink &action) {
-		auto result = PreparedText {};
+		auto result = PreparedText{};
 		result.links.push_back(fromLink());
 		result.text = lng_action_user_joined_by_link(lt_from, fromLinkText());
 		return result;
 	};
 
 	auto prepareChatCreate = [this](const MTPDmessageActionChatCreate &action) {
-		auto result = PreparedText {};
+		auto result = PreparedText{};
 		result.links.push_back(fromLink());
 		result.text = lng_action_created_chat(lt_from, fromLinkText(), lt_title, TextUtilities::Clean(qs(action.vtitle)));
 		return result;
@@ -97,7 +97,7 @@ void HistoryService::setMessageByAction(const MTPmessageAction &action) {
 	};
 
 	auto prepareChatDeletePhoto = [this] {
-		auto result = PreparedText {};
+		auto result = PreparedText{};
 		if (isPost()) {
 			result.text = lang(lng_action_removed_photo_channel);
 		} else {
@@ -108,7 +108,7 @@ void HistoryService::setMessageByAction(const MTPmessageAction &action) {
 	};
 
 	auto prepareChatDeleteUser = [this](const MTPDmessageActionChatDeleteUser &action) {
-		auto result = PreparedText {};
+		auto result = PreparedText{};
 		if (peerFromUser(action.vuser_id) == _from->id) {
 			result.links.push_back(fromLink());
 			result.text = lng_action_user_left(lt_from, fromLinkText());
@@ -122,7 +122,7 @@ void HistoryService::setMessageByAction(const MTPmessageAction &action) {
 	};
 
 	auto prepareChatEditPhoto = [this](const MTPDmessageActionChatEditPhoto &action) {
-		auto result = PreparedText {};
+		auto result = PreparedText{};
 		if (isPost()) {
 			result.text = lang(lng_action_changed_photo_channel);
 		} else {
@@ -133,7 +133,7 @@ void HistoryService::setMessageByAction(const MTPmessageAction &action) {
 	};
 
 	auto prepareChatEditTitle = [this](const MTPDmessageActionChatEditTitle &action) {
-		auto result = PreparedText {};
+		auto result = PreparedText{};
 		if (isPost()) {
 			result.text = lng_action_changed_title_channel(lt_title, TextUtilities::Clean(qs(action.vtitle)));
 		} else {
@@ -144,7 +144,7 @@ void HistoryService::setMessageByAction(const MTPmessageAction &action) {
 	};
 
 	auto prepareScreenshotTaken = [this] {
-		auto result = PreparedText {};
+		auto result = PreparedText{};
 		if (out()) {
 			result.text = lang(lng_action_you_took_screenshot);
 		} else {
@@ -155,7 +155,7 @@ void HistoryService::setMessageByAction(const MTPmessageAction &action) {
 	};
 
 	auto prepareCustomAction = [&](const MTPDmessageActionCustomAction &action) {
-		auto result = PreparedText {};
+		auto result = PreparedText{};
 		result.text = qs(action.vmessage);
 		return result;
 	};
@@ -214,69 +214,98 @@ void HistoryService::setMessageByAction(const MTPmessageAction &action) {
 		return result;
 	};
 
-	auto messageText = PreparedText {};
+	const auto messageText = action.match([&](
-
+		const MTPDmessageActionChatAddUser &data) {
-	switch (action.type()) {
+		return prepareChatAddUserText(data);
-	case mtpc_messageActionChatAddUser: messageText = prepareChatAddUserText(action.c_messageActionChatAddUser()); break;
+	}, [&](const MTPDmessageActionChatJoinedByLink &data) {
-	case mtpc_messageActionChatJoinedByLink: messageText = prepareChatJoinedByLink(action.c_messageActionChatJoinedByLink()); break;
+		return prepareChatJoinedByLink(data);
-	case mtpc_messageActionChatCreate: messageText = prepareChatCreate(action.c_messageActionChatCreate()); break;
+	}, [&](const MTPDmessageActionChatCreate &data) {
-	case mtpc_messageActionChannelCreate: messageText = prepareChannelCreate(action.c_messageActionChannelCreate()); break;
+		return prepareChatCreate(data);
-	case mtpc_messageActionHistoryClear: break; // Leave empty text.
+	}, [](const MTPDmessageActionChatMigrateTo &) {
-	case mtpc_messageActionChatDeletePhoto: messageText = prepareChatDeletePhoto(); break;
+		return PreparedText();
-	case mtpc_messageActionChatDeleteUser: messageText = prepareChatDeleteUser(action.c_messageActionChatDeleteUser()); break;
+	}, [](const MTPDmessageActionChannelMigrateFrom &) {
-	case mtpc_messageActionChatEditPhoto: messageText = prepareChatEditPhoto(action.c_messageActionChatEditPhoto()); break;
+		return PreparedText();
-	case mtpc_messageActionChatEditTitle: messageText = prepareChatEditTitle(action.c_messageActionChatEditTitle()); break;
+	}, [](const MTPDmessageActionHistoryClear &) {
-	case mtpc_messageActionChatMigrateTo: messageText.text = lang(lng_action_group_migrate); break;
+		return PreparedText();
-	case mtpc_messageActionChannelMigrateFrom: messageText.text = lang(lng_action_group_migrate); break;
+	}, [&](const MTPDmessageActionChannelCreate &data) {
-	case mtpc_messageActionPinMessage: messageText = preparePinnedText(); break;
+		return prepareChannelCreate(data);
-	case mtpc_messageActionGameScore: messageText = prepareGameScoreText(); break;
+	}, [&](const MTPDmessageActionChatDeletePhoto &) {
-	case mtpc_messageActionPhoneCall: Unexpected("PhoneCall type in HistoryService.");
+		return prepareChatDeletePhoto();
-	case mtpc_messageActionPaymentSent: messageText = preparePaymentSentText(); break;
+	}, [&](const MTPDmessageActionChatDeleteUser &data) {
-	case mtpc_messageActionScreenshotTaken: messageText = prepareScreenshotTaken(); break;
+		return prepareChatDeleteUser(data);
-	case mtpc_messageActionCustomAction: messageText = prepareCustomAction(action.c_messageActionCustomAction()); break;
+	}, [&](const MTPDmessageActionChatEditPhoto &data) {
-	case mtpc_messageActionBotAllowed: messageText = prepareBotAllowed(action.c_messageActionBotAllowed()); break;
+		return prepareChatEditPhoto(data);
-	case mtpc_messageActionSecureValuesSent: messageText = prepareSecureValuesSent(action.c_messageActionSecureValuesSent()); break;
+	}, [&](const MTPDmessageActionChatEditTitle &data) {
-	case mtpc_messageActionContactSignUp: messageText = prepareContactSignUp(); break;
+		return prepareChatEditTitle(data);
-	default: messageText.text = lang(lng_message_empty); break;
+	}, [&](const MTPDmessageActionPinMessage &) {
-	}
+		return preparePinnedText();
+	}, [&](const MTPDmessageActionGameScore &) {
+		return prepareGameScoreText();
+	}, [&](const MTPDmessageActionPhoneCall &) -> PreparedText {
+		Unexpected("PhoneCall type in HistoryService.");
+	}, [&](const MTPDmessageActionPaymentSent &) {
+		return preparePaymentSentText();
+	}, [&](const MTPDmessageActionScreenshotTaken &) {
+		return prepareScreenshotTaken();
+	}, [&](const MTPDmessageActionCustomAction &data) {
+		return prepareCustomAction(data);
+	}, [&](const MTPDmessageActionBotAllowed &data) {
+		return prepareBotAllowed(data);
+	}, [&](const MTPDmessageActionSecureValuesSent &data) {
+		return prepareSecureValuesSent(data);
+	}, [&](const MTPDmessageActionContactSignUp &data) {
+		return prepareContactSignUp();
+	}, [](const MTPDmessageActionPaymentSentMe &) {
+		LOG(("API Error: messageActionPaymentSentMe received."));
+		return PreparedText{ lang(lng_message_empty) };
+	}, [](const MTPDmessageActionSecureValuesSentMe &) {
+		LOG(("API Error: messageActionSecureValuesSentMe received."));
+		return PreparedText{ lang(lng_message_empty) };
+	}, [](const MTPDmessageActionEmpty &) {
+		return PreparedText{ lang(lng_message_empty) };
+	});
 
 	setServiceText(messageText);
 
 	// Additional information.
-	switch (action.type()) {
+	applyAction(action);
-	case mtpc_messageActionChatAddUser: {
+}
-		if (auto channel = history()->peer->asMegagroup()) {
+
-			auto &users = action.c_messageActionChatAddUser().vusers;
+void HistoryService::applyAction(const MTPMessageAction &action) {
-			for_const (auto &item, users.v) {
+	action.match([&](const MTPDmessageActionChatAddUser &data) {
-				if (item.v == history()->session().userId()) {
+		if (const auto channel = history()->peer->asMegagroup()) {
+			const auto selfUserId = history()->session().userId();
+			for (const auto &item : data.vusers.v) {
+				if (item.v == selfUserId) {
 					channel->mgInfo->joinedMessageFound = true;
 					break;
 				}
 			}
 		}
-	} break;
+	}, [&](const MTPDmessageActionChatJoinedByLink &data) {
-
+		if (_from->isSelf()) {
-	case mtpc_messageActionChatJoinedByLink: {
+			if (const auto channel = history()->peer->asMegagroup()) {
-		if (_from->isSelf() && history()->peer->isMegagroup()) {
+				channel->mgInfo->joinedMessageFound = true;
-			history()->peer->asChannel()->mgInfo->joinedMessageFound = true;
+			}
 		}
-	} break;
+	}, [&](const MTPDmessageActionChatEditPhoto &data) {
-
+		data.vphoto.match([&](const MTPDphoto &photo) {
-	case mtpc_messageActionChatEditPhoto: {
-		auto &photo = action.c_messageActionChatEditPhoto().vphoto;
-		if (photo.type() == mtpc_photo) {
 			_media = std::make_unique<Data::MediaPhoto>(
 				this,
 				history()->peer,
-				history()->owner().photo(photo.c_photo()));
+				history()->owner().photo(photo));
-		}
+		}, [](const MTPDphotoEmpty &) {
-	} break;
+		});
-
+	}, [&](const MTPDmessageActionChatCreate &) {
-	case mtpc_messageActionChatMigrateTo:
+		_flags |= MTPDmessage_ClientFlag::f_is_group_essential;
-	case mtpc_messageActionChannelMigrateFrom: {
+	}, [&](const MTPDmessageActionChannelCreate &) {
-		_flags |= MTPDmessage_ClientFlag::f_is_group_migrate;
+		_flags |= MTPDmessage_ClientFlag::f_is_group_essential;
-	} break;
+	}, [&](const MTPDmessageActionChatMigrateTo &) {
-	}
+		_flags |= MTPDmessage_ClientFlag::f_is_group_essential;
+	}, [&](const MTPDmessageActionChannelMigrateFrom &) {
+		_flags |= MTPDmessage_ClientFlag::f_is_group_essential;
+	}, [](const auto &) {
+	});
 }
 
 void HistoryService::setSelfDestruct(HistoryServiceSelfDestruct::Type type, int ttlSeconds) {

Telegram/SourceFiles/history/history_service.h

@@ -137,7 +137,10 @@ private:
 	void createFromMtp(const MTPDmessage &message);
 	void createFromMtp(const MTPDmessageService &message);
 	void setMessageByAction(const MTPmessageAction &action);
-	void setSelfDestruct(HistoryServiceSelfDestruct::Type type, int ttlSeconds);
+	void setSelfDestruct(
+		HistoryServiceSelfDestruct::Type type,
+		int ttlSeconds);
+	void applyAction(const MTPMessageAction &action);
 
 	PreparedText preparePinnedText();
 	PreparedText prepareGameScoreText();

Telegram/SourceFiles/history/history_widget.cpp

@@ -730,26 +730,6 @@ void HistoryWidget::highlightMessage(MsgId universalMessageId) {
 	_highlightStart = getms();
 	_highlightedMessageId = universalMessageId;
 	_highlightTimer.callEach(AnimationTimerDelta);
-
-	adjustHighlightedMessageToMigrated();
-}
-
-void HistoryWidget::adjustHighlightedMessageToMigrated() {
-	if (_history
-		&& _highlightTimer.isActive()
-		&& _highlightedMessageId > 0
-		&& _migrated
-		&& !_migrated->isEmpty()
-		&& _migrated->loadedAtBottom()
-		&& _migrated->blocks.back()->messages.back()->data()->isGroupMigrate()
-		&& _list->historyTop() != _list->historyDrawTop()) {
-		auto highlighted = App::histItemById(
-			_history->channelId(),
-			_highlightedMessageId);
-		if (highlighted && highlighted->isGroupMigrate()) {
-			_highlightedMessageId = -_migrated->blocks.back()->messages.back()->data()->id;
-		}
-	}
 }
 
 void HistoryWidget::checkNextHighlight() {
@@ -4902,7 +4882,6 @@ void HistoryWidget::addMessagesToFront(PeerData *peer, const QVector<MTPMessage>
 	_list->messagesReceived(peer, messages);
 	if (!_firstLoadRequest) {
 		updateHistoryGeometry();
-		adjustHighlightedMessageToMigrated();
 		updateBotKeyboard();
 	}
 }
@@ -5553,22 +5532,15 @@ void HistoryWidget::replyToMessage(not_null<HistoryItem*> item) {
 		return;
 	}
 	if (item->history() == _migrated) {
-		if (item->isGroupMigrate()
+		if (item->serviceMsg()) {
-			&& !_history->isEmpty()
+			Ui::show(Box<InformBox>(lang(lng_reply_cant)));
-			&& _history->blocks.front()->messages.front()->data()->isGroupMigrate()
-			&& _history != _migrated) {
-			replyToMessage(_history->blocks.front()->messages.front()->data());
 		} else {
-			if (item->serviceMsg()) {
+			const auto itemId = item->fullId();
-				Ui::show(Box<InformBox>(lang(lng_reply_cant)));
+			Ui::show(Box<ConfirmBox>(lang(lng_reply_cant_forward), lang(lng_selected_forward), crl::guard(this, [=] {
-			} else {
+				App::main()->setForwardDraft(
-				const auto itemId = item->fullId();
+					_peer->id,
-				Ui::show(Box<ConfirmBox>(lang(lng_reply_cant_forward), lang(lng_selected_forward), crl::guard(this, [=] {
+					{ 1, itemId });
-					App::main()->setForwardDraft(
+			})));
-						_peer->id,
-						{ 1, itemId });
-				})));
-			}
 		}
 		return;
 	}

Telegram/SourceFiles/history/history_widget.h

@@ -387,7 +387,6 @@ private:
 	void supportShareContact(Support::Contact contact);
 
 	void highlightMessage(MsgId universalMessageId);
-	void adjustHighlightedMessageToMigrated();
 	void checkNextHighlight();
 	void updateHighlightedMessage();
 	void clearHighlightMessages();

Telegram/SourceFiles/history/view/history_view_top_bar_widget.cpp

@@ -310,7 +310,7 @@ void TopBarWidget::paintTopBar(Painter &p, TimeMs ms) {
 
 	p.setPen(st::dialogsNameFg);
 	if (const auto feed = _activeChat.feed()) {
-		auto text = feed->chatsListName(); // TODO feed name emoji
+		auto text = feed->chatListName(); // TODO feed name emoji
 		auto textWidth = st::historySavedFont->width(text);
 		if (namewidth < textWidth) {
 			text = st::historySavedFont->elided(text, namewidth);

Telegram/SourceFiles/info/feed/info_feed_cover.cpp

@@ -71,7 +71,7 @@ void Cover::initViewers() {
 }
 
 void Cover::refreshNameText() {
-	_name->setText(_feed->chatsListName());
+	_name->setText(_feed->chatListName());
 	refreshNameGeometry(width());
 }
 

Telegram/SourceFiles/mainwidget.cpp

@@ -731,9 +731,7 @@ void MainWidget::cancelUploadLayer(not_null<HistoryItem*> item) {
 		if (const auto item = App::histItemById(itemId)) {
 			const auto history = item->history();
 			item->destroy();
-			if (!history->lastMessageKnown()) {
+			history->requestChatListMessage();
-				Auth().api().requestDialogEntry(history);
-			}
 			Auth().data().sendHistoryChangeNotifications();
 		}
 		Auth().uploader().unpause();
@@ -831,7 +829,7 @@ void MainWidget::deleteHistoryPart(DeleteHistoryRequest request, const MTPmessag
 void MainWidget::deleteMessages(
 		not_null<PeerData*> peer,
 		const QVector<MTPint> &ids,
-		bool forEveryone) {
+		bool revoke) {
 	if (const auto channel = peer->asChannel()) {
 		MTP::send(
 			MTPchannels_DeleteMessages(
@@ -839,13 +837,10 @@ void MainWidget::deleteMessages(
 				MTP_vector<MTPint>(ids)),
 			rpcDone(&MainWidget::messagesAffected, peer));
 	} else {
-		auto flags = MTPmessages_DeleteMessages::Flags(0);
+		using Flag = MTPmessages_DeleteMessages::Flag;
-		if (forEveryone) {
-			flags |= MTPmessages_DeleteMessages::Flag::f_revoke;
-		}
 		MTP::send(
 			MTPmessages_DeleteMessages(
-				MTP_flags(flags),
+				MTP_flags(revoke ? Flag::f_revoke : Flag(0)),
 				MTP_vector<MTPint>(ids)),
 			rpcDone(&MainWidget::messagesAffected, peer));
 	}
@@ -1039,9 +1034,7 @@ void MainWidget::messagesAffected(
 	}
 
 	if (const auto history = App::historyLoaded(peer)) {
-		if (!history->lastMessageKnown()) {
+		history->requestChatListMessage();
-			Auth().api().requestDialogEntry(history);
-		}
 	}
 }
 
@@ -4003,9 +3996,7 @@ void MainWidget::feedUpdate(const MTPUpdate &update) {
 				if (existing && !local->mainView()) {
 					const auto history = local->history();
 					local->destroy();
-					if (!history->lastMessageKnown()) {
+					history->requestChatListMessage();
-						Auth().api().requestDialogEntry(history);
-					}
 				} else {
 					if (existing) {
 						existing->destroy();
@@ -4477,15 +4468,15 @@ void MainWidget::feedUpdate(const MTPUpdate &update) {
 				Auth().api().requestSelfParticipant(channel);
 			}
 			if (const auto feed = channel->feed()) {
-				if (!feed->lastMessageKnown()
+				feed->requestChatListMessage();
-					|| !feed->unreadCountKnown()) {
+				if (!feed->unreadCountKnown()) {
-					Auth().api().requestDialogEntry(feed);
+					feed->session().api().requestDialogEntry(feed);
 				}
 			} else if (channel->amIn()) {
 				const auto history = App::history(channel->id);
-				if (!history->lastMessageKnown()
+				history->requestChatListMessage();
-					|| !history->unreadCountKnown()) {
+				if (!history->unreadCountKnown()) {
-					Auth().api().requestDialogEntry(history);
+					history->session().api().requestDialogEntry(history);
 				}
 			}
 		}

Telegram/SourceFiles/mainwidget.h

@@ -196,7 +196,7 @@ public:
 	void deleteMessages(
 		not_null<PeerData*> peer,
 		const QVector<MTPint> &ids,
-		bool forEveryone);
+		bool revoke);
 	void deletedContact(UserData *user, const MTPcontacts_Link &result);
 	void deleteConversation(
 		not_null<PeerData*> peer,

Telegram/SourceFiles/mtproto/dedicated_file_loader.cpp

@@ -409,22 +409,13 @@ void ResolveChannel(
 
 std::optional<MTPMessage> GetMessagesElement(
 		const MTPmessages_Messages &list) {
-	const auto get = [](auto &&data) -> std::optional<MTPMessage> {
+	return list.match([&](const MTPDmessages_messagesNotModified &) {
+		return std::optional<MTPMessage>(std::nullopt);
+	}, [&](const auto &data) {
 		return data.vmessages.v.isEmpty()
 			? std::nullopt
-			: base::make_optional(data.vmessages.v[0]);
+			: std::make_optional(data.vmessages.v[0]);
-	};
+	});
-	switch (list.type()) {
-	case mtpc_messages_messages:
-		return get(list.c_messages_messages());
-	case mtpc_messages_messagesSlice:
-		return get(list.c_messages_messagesSlice());
-	case mtpc_messages_channelMessages:
-		return get(list.c_messages_channelMessages());
-	case mtpc_messages_messagesNotModified:
-		return std::nullopt;
-	default: Unexpected("Type of messages.Messages (GetMessagesElement)");
-	}
 }
 
 void StartDedicatedLoader(

Telegram/SourceFiles/mtproto/type_utils.h

@@ -38,8 +38,8 @@ enum class MTPDmessage_ClientFlag : uint32 {
 	// message has links for "shared links" indexing
 	f_has_text_links = (1U << 30),
 
-	// message is a group migrate (group -> supergroup) service message
+	// message is a group / channel create or migrate service message
-	f_is_group_migrate = (1U << 29),
+	f_is_group_essential = (1U << 29),
 
 	//// message needs initDimensions() + resize() + paint()
 	//f_pending_init_dimensions = (1U << 28),

Telegram/SourceFiles/passport/passport_panel_edit_document.cpp

@@ -643,7 +643,7 @@ bool PanelEditDocument::validate() {
 		error = firsttop.y();
 	}
 	auto first = QPointer<PanelDetailsRow>();
-	for (const auto [i, field] : base::reversed(_details)) {
+	for (const auto [i, field] : ranges::view::reverse(_details)) {
 		const auto &row = _scheme.rows[i];
 		if (row.valueClass == Scheme::ValueClass::Additional
 			&& !_additionalShown) {

Telegram/SourceFiles/window/window_controller.cpp

@@ -407,14 +407,14 @@ void Controller::showJumpToDate(Dialogs::Key chat, QDate requestedDate) {
 						return history->blocks.front()->messages.front()->dateTime().date();
 					}
 				}
-			} else if (history->chatsListTimeId() != 0) {
+			} else if (history->chatListTimeId() != 0) {
-				return ParseDateTime(history->chatsListTimeId()).date();
+				return ParseDateTime(history->chatListTimeId()).date();
 			}
 		} else if (const auto feed = chat.feed()) {
 			/*if (chatScrollPosition(feed)) { // #TODO feeds save position
 
-			} else */if (feed->chatsListTimeId() != 0) {
+			} else */if (feed->chatListTimeId() != 0) {
-				return ParseDateTime(feed->chatsListTimeId()).date();
+				return ParseDateTime(feed->chatListTimeId()).date();
 			}
 		}
 		return QDate::currentDate();
@@ -424,12 +424,12 @@ void Controller::showJumpToDate(Dialogs::Key chat, QDate requestedDate) {
 			if (const auto channel = history->peer->migrateTo()) {
 				history = App::historyLoaded(channel);
 			}
-			if (history && history->chatsListTimeId() != 0) {
+			if (history && history->chatListTimeId() != 0) {
-				return ParseDateTime(history->chatsListTimeId()).date();
+				return ParseDateTime(history->chatListTimeId()).date();
 			}
 		} else if (const auto feed = chat.feed()) {
-			if (feed->chatsListTimeId() != 0) {
+			if (feed->chatListTimeId() != 0) {
-				return ParseDateTime(feed->chatsListTimeId()).date();
+				return ParseDateTime(feed->chatListTimeId()).date();
 			}
 		}
 		return QDate::currentDate();