Support topic on-the-fly creation.

Telegram/SourceFiles/api/api_polls.cpp

@@ -71,10 +71,10 @@ void Polls::create(
 		history,
 		replyTo,
 		randomId,
-		MTPmessages_SendMedia(
+		Data::Histories::PrepareMessage<MTPmessages_SendMedia>(
 			MTP_flags(sendFlags),
 			peer->input,
-			MTP_int(replyTo),
+			Data::Histories::ReplyToPlaceholder(),
 			PollDataToInputMedia(&data),
 			MTP_string(),
 			MTP_long(randomId),

Telegram/SourceFiles/api/api_sending.cpp

@@ -148,10 +148,10 @@ void SendExistingMedia(
 			history,
 			replyTo,
 			randomId,
-			MTPmessages_SendMedia(
+			Data::Histories::PrepareMessage<MTPmessages_SendMedia>(
 				MTP_flags(sendFlags),
 				peer->input,
-				MTP_int(replyTo),
+				Data::Histories::ReplyToPlaceholder(),
 				inputMedia(),
 				MTP_string(captionText),
 				MTP_long(randomId),
@@ -314,10 +314,10 @@ bool SendDice(MessageToSend &message) {
 		history,
 		replyTo,
 		randomId,
-		MTPmessages_SendMedia(
+		Data::Histories::PrepareMessage<MTPmessages_SendMedia>(
 			MTP_flags(sendFlags),
 			peer->input,
-			MTP_int(replyTo),
+			Data::Histories::ReplyToPlaceholder(),
 			MTP_inputMediaDice(MTP_string(emoji)),
 			MTP_string(),
 			MTP_long(randomId),
@@ -347,9 +347,9 @@ void SendConfirmedFile(
 		&& (file->to.replaceMediaOf != 0);
 	const auto newId = FullMsgId(
 		file->to.peer,
-		isEditing
+		(isEditing
 			? file->to.replaceMediaOf
-			: session->data().nextLocalMessageId());
+			: session->data().nextLocalMessageId()));
 	const auto groupId = file->album ? file->album->groupId : uint64(0);
 	if (file->album) {
 		const auto proj = [](const SendingAlbum::Item &item) {
@@ -360,15 +360,21 @@ void SendConfirmedFile(
 
 		it->msgId = newId;
 	}
-	session->uploader().upload(newId, file);
 
 	const auto itemToEdit = isEditing
 		? session->data().message(newId)
 		: nullptr;
-
 	const auto history = session->data().history(file->to.peer);
 	const auto peer = history->peer;
 
+	if (!isEditing) {
+		file->to.replyTo = session->data().histories().convertTopicReplyTo(
+			history,
+			file->to.replyTo);
+	}
+
+	session->uploader().upload(newId, file);
+
 	auto action = SendAction(history, file->to.options);
 	action.clearDraft = false;
 	action.replyTo = file->to.replyTo;

Telegram/SourceFiles/api/api_updates.cpp

@@ -1534,7 +1534,8 @@ void Updates::feedUpdate(const MTPUpdate &update) {
 		const auto randomId = d.vrandom_id().v;
 		if (const auto id = session().data().messageIdByRandomId(randomId)) {
 			const auto newId = d.vid().v;
-			if (const auto local = session().data().message(id)) {
+			auto &owner = session().data();
+			if (const auto local = owner.message(id)) {
 				if (local->isScheduled()) {
 					session().data().scheduledMessages().apply(d, local);
 				} else {
@@ -1552,6 +1553,8 @@ void Updates::feedUpdate(const MTPUpdate &update) {
 						local->setRealId(d.vid().v);
 					}
 				}
+			} else {
+				owner.histories().checkTopicCreated(id, newId);
 			}
 			session().data().unregisterMessageRandomId(randomId);
 		}

Telegram/SourceFiles/apiwrap.cpp

@@ -3494,10 +3494,10 @@ void ApiWrap::sendMessage(MessageToSend &&message) {
 			history,
 			replyTo,
 			randomId,
-			MTPmessages_SendMessage(
+			Data::Histories::PrepareMessage<MTPmessages_SendMessage>(
 				MTP_flags(sendFlags),
 				peer->input,
-				MTP_int(replyTo),
+				Data::Histories::ReplyToPlaceholder(),
 				msgText,
 				MTP_long(randomId),
 				MTPReplyMarkup(),
@@ -3637,10 +3637,10 @@ void ApiWrap::sendInlineResult(
 		history,
 		replyTo,
 		randomId,
-		MTPmessages_SendInlineBotResult(
+		Data::Histories::PrepareMessage<MTPmessages_SendInlineBotResult>(
 			MTP_flags(sendFlags),
 			peer->input,
-			MTP_int(replyTo),
+			Data::Histories::ReplyToPlaceholder(),
 			MTP_long(randomId),
 			MTP_long(data->getQueryId()),
 			MTP_string(data->getId()),
@@ -3784,10 +3784,10 @@ void ApiWrap::sendMediaWithRandomId(
 		history,
 		replyTo,
 		randomId,
-		MTPmessages_SendMedia(
+		Data::Histories::PrepareMessage<MTPmessages_SendMedia>(
 			MTP_flags(flags),
 			peer->input,
-			MTP_int(replyTo),
+			Data::Histories::ReplyToPlaceholder(),
 			media,
 			MTP_string(caption.text),
 			MTP_long(randomId),
@@ -3889,10 +3889,10 @@ void ApiWrap::sendAlbumIfReady(not_null<SendingAlbum*> album) {
 		history,
 		replyTo,
 		uint64(0), // randomId
-		MTPmessages_SendMultiMedia(
+		Data::Histories::PrepareMessage<MTPmessages_SendMultiMedia>(
 			MTP_flags(flags),
 			peer->input,
-			MTP_int(replyTo),
+			Data::Histories::ReplyToPlaceholder(),
 			MTP_vector<MTPInputSingleMedia>(medias),
 			MTP_int(album->options.scheduled),
 			(sendAs ? sendAs->input : MTP_inputPeerEmpty())

Telegram/SourceFiles/boxes/peers/add_bot_to_chat_box.cpp

@@ -69,10 +69,10 @@ void ShareBotGame(
 		history,
 		replyTo,
 		randomId,
-		MTPmessages_SendMedia(
+		Data::Histories::PrepareMessage<MTPmessages_SendMedia>(
 			MTP_flags(0),
 			chat->input,
-			MTP_int(0),
+			Data::Histories::ReplyToPlaceholder(),
 			MTP_inputMediaGame(
 				MTP_inputGameShortName(
 					bot->inputUser,

Telegram/SourceFiles/boxes/peers/edit_forum_topic_box.cpp

@@ -139,7 +139,8 @@ void EditForumTopicBox(
 
 	const auto requestId = std::make_shared<mtpRequestId>();
 	const auto create = [=] {
-		if (!forum->peer->isForum()) {
+		const auto channel = forum->peer->asChannel();
+		if (!channel || !channel->isForum()) {
 			box->closeBox();
 			return;
 		} else if (title->getLastText().trimmed().isEmpty()) {
@@ -149,30 +150,10 @@ void EditForumTopicBox(
 		controller->showSection(
 			std::make_shared<HistoryView::RepliesMemento>(
 				forum,
-				forum->peer->forum()->reserveCreatingId(
+				channel->forum()->reserveCreatingId(
 					title->getLastText().trimmed(),
 					state->iconId)),
 			Window::SectionShow::Way::ClearStack);
-#if 0 // #TODO forum create
-		const auto randomId = base::RandomValue<uint64>();
-		const auto api = &forum->session().api();
-		api->request(MTPchannels_CreateForumTopic(
-			MTP_flags(0),
-			forum->inputChannel,
-			MTP_string(title->getLastText().trimmed()),
-			MTPlong(), // icon_emoji_id
-			MTPInputMedia(),
-			MTP_string(message->getLastText().trimmed()),
-			MTP_long(randomId),
-			MTPVector<MTPMessageEntity>(),
-			MTPInputPeer() // send_as
-		)).done([=](const MTPUpdates &result) {
-			api->applyUpdates(result, randomId);
-			box->closeBox();
-		}).fail([=](const MTP::Error &error) {
-			api->sendMessageFail(error, forum, randomId);
-		}).send();
-#endif
 	};
 
 	const auto save = [=] {

Telegram/SourceFiles/data/data_forum.cpp

@@ -124,20 +124,18 @@ void Forum::applyTopicAdded(
 		MsgId rootId,
 		const QString &title,
 		DocumentId iconId) {
-	if (const auto i = _topics.find(rootId); i != end(_topics)) {
+	const auto i = _topics.find(rootId);
-		i->second->applyTitle(title);
+	const auto raw = (i != end(_topics))
-		i->second->applyIconId(iconId);
+		? i->second.get()
-	} else {
+		: _topics.emplace(
-		const auto raw = _topics.emplace(
 			rootId,
 			std::make_unique<ForumTopic>(_history, rootId)
 		).first->second.get();
-		raw->applyTitle(title);
+	raw->applyTitle(title);
-		raw->applyIconId(iconId);
+	raw->applyIconId(iconId);
-		if (!creating(rootId)) {
+	if (!creating(rootId)) {
-			raw->addToChatList(FilterId(), topicsList());
+		raw->addToChatList(FilterId(), topicsList());
-			_chatsListChanges.fire({});
+		_chatsListChanges.fire({});
-		}
 	}
 }
 
@@ -171,6 +169,25 @@ bool Forum::creating(MsgId rootId) const {
 	return _creatingRootIds.contains(rootId);
 }
 
+void Forum::created(MsgId rootId, MsgId realId) {
+	if (rootId == realId) {
+		return;
+	}
+	_creatingRootIds.remove(rootId);
+	const auto i = _topics.find(rootId);
+	Assert(i != end(_topics));
+	auto topic = std::move(i->second);
+	_topics.erase(i);
+	const auto id = FullMsgId(_history->peer->id, realId);
+	if (!_topics.contains(realId)) {
+		_topics.emplace(
+			realId,
+			std::move(topic)
+		).first->second->setRealRootId(realId);
+	}
+	_history->owner().notifyItemIdChange({ id, rootId });
+}
+
 ForumTopic *Forum::topicFor(not_null<HistoryItem*> item) {
 	const auto maybe = topicFor(item->replyToTop());
 	return maybe ? maybe : topicFor(item->topicRootId());

Telegram/SourceFiles/data/data_forum.h

@@ -36,6 +36,7 @@ public:
 		const QString &title,
 		DocumentId iconId);
 	void applyTopicRemoved(MsgId rootId);
+	void applyTopicCreated(MsgId rootId, MsgId realId);
 	[[nodiscard]] ForumTopic *topicFor(not_null<HistoryItem*> item);
 	[[nodiscard]] ForumTopic *topicFor(MsgId rootId);
 
@@ -46,6 +47,7 @@ public:
 		DocumentId iconId);
 	void discardCreatingId(MsgId rootId);
 	[[nodiscard]] bool creating(MsgId rootId) const;
+	void created(MsgId rootId, MsgId realId);
 
 private:
 	void applyReceivedTopics(

Telegram/SourceFiles/data/data_forum_topic.cpp

@@ -29,6 +29,8 @@ ForumTopic::ForumTopic(not_null<History*> history, MsgId rootId)
 , _rootId(rootId) {
 }
 
+ForumTopic::~ForumTopic() = default;
+
 not_null<ChannelData*> ForumTopic::channel() const {
 	return _history->peer->asChannel();
 }
@@ -45,6 +47,10 @@ MsgId ForumTopic::rootId() const {
 	return _rootId;
 }
 
+void ForumTopic::setRealRootId(MsgId realId) {
+	_rootId = realId;
+}
+
 void ForumTopic::applyTopic(const MTPForumTopic &topic) {
 	Expects(_rootId == topic.data().vid().v);
 

Telegram/SourceFiles/data/data_forum_topic.h

@@ -30,6 +30,7 @@ public:
 	static constexpr auto kGeneralId = 1;
 
 	ForumTopic(not_null<History*> history, MsgId rootId);
+	~ForumTopic();
 
 	ForumTopic(const ForumTopic &) = delete;
 	ForumTopic &operator=(const ForumTopic &) = delete;
@@ -42,6 +43,8 @@ public:
 		return (_rootId == kGeneralId);
 	}
 
+	void setRealRootId(MsgId realId);
+
 	void applyTopic(const MTPForumTopic &topic);
 
 	TimeId adjustedChatListTimeId() const override;
@@ -109,7 +112,7 @@ private:
 
 	const not_null<History*> _history;
 	const not_null<Dialogs::MainList*> _list;
-	const MsgId _rootId = 0;
+	MsgId _rootId = 0;
 
 	QString _title;
 	DocumentId _iconId = 0;

Telegram/SourceFiles/data/data_histories.cpp

@@ -11,8 +11,11 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "data/data_channel.h"
 #include "data/data_chat.h"
 #include "data/data_folder.h"
+#include "data/data_forum.h"
+#include "data/data_forum_topic.h"
 #include "data/data_scheduled_messages.h"
 #include "base/unixtime.h"
+#include "base/random.h"
 #include "main/main_session.h"
 #include "window/notifications_manager.h"
 #include "history/history.h"
@@ -841,14 +844,74 @@ int Histories::sendRequest(
 	return id;
 }
 
+void Histories::sendCreateTopicRequest(
+		not_null<History*> history,
+		MsgId rootId) {
+	Expects(history->peer->isChannel());
+
+	const auto forum = history->peer->forum();
+	Assert(forum != nullptr);
+	const auto topic = forum->topicFor(rootId);
+	Assert(topic != nullptr);
+	const auto randomId = base::RandomValue<uint64>();
+	session().data().registerMessageRandomId(
+		randomId,
+		{ history->peer->id, rootId });
+	const auto api = &session().api();
+	using Flag = MTPchannels_CreateForumTopic::Flag;
+	api->request(MTPchannels_CreateForumTopic(
+		MTP_flags(topic->iconId() ? Flag::f_icon_emoji_id : Flag(0)),
+		history->peer->asChannel()->inputChannel,
+		MTP_string(topic->title()),
+		MTP_long(topic->iconId()),
+		MTP_long(randomId),
+		MTPInputPeer() // send_as
+	)).done([=](const MTPUpdates &result) {
+		//AssertIsDebug();
+		//const auto id = result.c_updates().vupdates().v.front().c_updateMessageID().vrandom_id().v;
+		//session().data().registerMessageRandomId(
+		//	id,
+		//	{ history->peer->id, rootId });
+		api->applyUpdates(result, randomId);
+	}).fail([=](const MTP::Error &error) {
+		api->sendMessageFail(error, history->peer, randomId);
+	}).send();
+}
+
+bool Histories::isCreatingTopic(
+		not_null<History*> history,
+		MsgId rootId) const {
+	const auto forum = history->peer->forum();
+	return forum && forum->creating(rootId);
+}
+
 int Histories::sendPreparedMessage(
 		not_null<History*> history,
 		MsgId replyTo,
 		uint64 randomId,
-		PreparedMessage message,
+		Fn<PreparedMessage(MsgId replyTo)> message,
 		Fn<void(const MTPUpdates&, const MTP::Response&)> done,
 		Fn<void(const MTP::Error&, const MTP::Response&)> fail) {
-	return v::match(message, [&](const auto &request) {
+	if (isCreatingTopic(history, replyTo)) {
+		const auto id = ++_requestAutoincrement;
+		const auto creatingId = FullMsgId(history->peer->id, replyTo);
+		auto i = _creatingTopics.find(creatingId);
+		if (i == end(_creatingTopics)) {
+			sendCreateTopicRequest(history, replyTo);
+			i = _creatingTopics.emplace(creatingId).first;
+		}
+		i->second.push_back({
+			.randomId = randomId,
+			.message = std::move(message),
+			.done = std::move(done),
+			.fail = std::move(fail),
+			.requestId = id,
+		});
+		_creatingTopicRequests.emplace(id);
+		return id;
+	}
+	const auto realTo = convertTopicReplyTo(history, replyTo);
+	return v::match(message(realTo), [&](const auto &request) {
 		const auto type = RequestType::Send;
 		return sendRequest(history, type, [=](Fn<void()> finish) {
 			const auto session = &_owner->session();
@@ -874,6 +937,54 @@ int Histories::sendPreparedMessage(
 	});
 }
 
+void Histories::checkTopicCreated(FullMsgId rootId, MsgId realId) {
+	const auto i = _creatingTopics.find(rootId);
+	if (i != end(_creatingTopics)) {
+		auto scheduled = base::take(i->second);
+		_creatingTopics.erase(i);
+
+		_createdTopicIds.emplace(rootId, realId);
+
+		if (const auto forum = _owner->peer(rootId.peer)->forum()) {
+			forum->created(rootId.msg, realId);
+		}
+
+		const auto history = _owner->history(rootId.peer);
+		for (auto &entry : scheduled) {
+			_creatingTopicRequests.erase(entry.requestId);
+			//AssertIsDebug();
+			sendPreparedMessage(
+				history,
+				realId,
+				entry.randomId,
+				std::move(entry.message),
+				std::move(entry.done),
+				std::move(entry.fail));
+		}
+		for (const auto &item : history->clientSideMessages()) {
+			const auto replace = [&](MsgId nowId) {
+				return (nowId == rootId.msg) ? realId : nowId;
+			};
+			if (item->replyToTop() == rootId.msg) {
+				item->setReplyFields(
+					replace(item->replyToId()),
+					realId,
+					true);
+			}
+		}
+	}
+}
+
+MsgId Histories::convertTopicReplyTo(
+		not_null<History*> history,
+		MsgId replyTo) const {
+	if (!replyTo) {
+		return {};
+	}
+	const auto i = _createdTopicIds.find({ history->peer->id, replyTo });
+	return (i != end(_createdTopicIds)) ? i->second : replyTo;
+}
+
 void Histories::checkPostponed(not_null<History*> history, int id) {
 	if (const auto state = lookup(history)) {
 		finishSentRequest(history, state, id);
@@ -883,6 +994,9 @@ void Histories::checkPostponed(not_null<History*> history, int id) {
 void Histories::cancelRequest(int id) {
 	if (!id) {
 		return;
+	} else if (_creatingTopicRequests.contains(id)) {
+		cancelDelayedByTopicRequest(id);
+		return;
 	}
 	const auto history = _historyByRequest.take(id);
 	if (!history) {
@@ -896,6 +1010,15 @@ void Histories::cancelRequest(int id) {
 	finishSentRequest(*history, state, id);
 }
 
+void Histories::cancelDelayedByTopicRequest(int id) {
+	for (auto &[rootId, messages] : _creatingTopics) {
+		messages.erase(
+			ranges::remove(messages, id, &DelayedByTopicMessage::requestId),
+			end(messages));
+	}
+	_creatingTopicRequests.remove(id);
+}
+
 void Histories::finishSentRequest(
 		not_null<History*> history,
 		not_null<State*> state,

Telegram/SourceFiles/data/data_histories.h

@@ -104,10 +104,25 @@ public:
 		not_null<History*> history,
 		MsgId replyTo,
 		uint64 randomId,
-		PreparedMessage message,
+		Fn<PreparedMessage(MsgId replyTo)> message,
-		Fn<void(const MTPUpdates&, const MTP::Response &)> done,
+		Fn<void(const MTPUpdates&, const MTP::Response&)> done,
 		Fn<void(const MTP::Error&, const MTP::Response&)> fail);
 
+	struct ReplyToPlaceholder {
+	};
+	template <typename RequestType, typename ...Args>
+	static Fn<Histories::PreparedMessage(MsgId)> PrepareMessage(
+			const Args &...args) {
+		return [=](MsgId replyTo) {
+			return RequestType(ReplaceReplyTo(args, replyTo)...);
+		};
+	}
+
+	void checkTopicCreated(FullMsgId rootId, MsgId realId);
+	[[nodiscard]] MsgId convertTopicReplyTo(
+		not_null<History*> history,
+		MsgId replyTo) const;
+
 private:
 	struct PostponedHistoryRequest {
 		Fn<mtpRequestId(Fn<void()> finish)> generator;
@@ -130,6 +145,22 @@ private:
 		MsgId aroundId = 0;
 		mtpRequestId requestId = 0;
 	};
+	struct DelayedByTopicMessage {
+		uint64 randomId = 0;
+		Fn<PreparedMessage(MsgId replyTo)> message;
+		Fn<void(const MTPUpdates&, const MTP::Response&)> done;
+		Fn<void(const MTP::Error&, const MTP::Response&)> fail;
+		int requestId = 0;
+	};
+
+	template <typename Arg>
+	static auto ReplaceReplyTo(Arg arg, MsgId replyTo) {
+		return arg;
+	}
+	template <>
+	static auto ReplaceReplyTo(ReplyToPlaceholder, MsgId replyTo) {
+		return MTP_int(replyTo);
+	}
 
 	void readInboxTill(not_null<History*> history, MsgId tillId, bool force);
 	void sendReadRequests();
@@ -147,6 +178,12 @@ private:
 
 	void sendDialogRequests();
 
+	[[nodiscard]] bool isCreatingTopic(
+		not_null<History*> history,
+		MsgId rootId) const;
+	void sendCreateTopicRequest(not_null<History*> history, MsgId rootId);
+	void cancelDelayedByTopicRequest(int id);
+
 	const not_null<Session*> _owner;
 
 	std::unordered_map<PeerId, std::unique_ptr<History>> _map;
@@ -169,6 +206,12 @@ private:
 		not_null<History*>,
 		ChatListGroupRequest> _chatListGroupRequests;
 
+	base::flat_map<
+		FullMsgId,
+		std::vector<DelayedByTopicMessage>> _creatingTopics;
+	base::flat_map<FullMsgId, MsgId> _createdTopicIds;
+	base::flat_set<mtpRequestId> _creatingTopicRequests;
+
 };
 
 } // namespace Data

Telegram/SourceFiles/data/data_replies_list.cpp

@@ -137,9 +137,6 @@ void RepliesList::appendClientSideMessages(MessagesSlice &slice) {
 		}
 		slice.ids.reserve(messages.size());
 		for (const auto &item : messages) {
-			const auto checkId = (_rootId == ForumTopic::kGeneralId)
-				? item->topicRootId()
-				: item->replyToTop();
 			if (!item->inThread(_rootId)) {
 				continue;
 			}

Telegram/SourceFiles/data/data_session.cpp

@@ -1407,10 +1407,12 @@ rpl::producer<not_null<HistoryItem*>> Session::newItemAdded() const {
 	return _newItemAdded.events();
 }
 
-void Session::changeMessageId(PeerId peerId, MsgId wasId, MsgId nowId) {
+HistoryItem *Session::changeMessageId(PeerId peerId, MsgId wasId, MsgId nowId) {
 	const auto list = messagesListForInsert(peerId);
-	auto i = list->find(wasId);
+	const auto i = list->find(wasId);
-	Assert(i != list->end());
+	if (i == list->end()) {
+		return nullptr;
+	}
 	const auto item = i->second;
 	list->erase(i);
 	const auto [j, ok] = list->emplace(nowId, item);
@@ -1427,6 +1429,7 @@ void Session::changeMessageId(PeerId peerId, MsgId wasId, MsgId nowId) {
 	}
 
 	Ensures(ok);
+	return item;
 }
 
 bool Session::queryItemVisibility(not_null<HistoryItem*> item) const {
@@ -1448,19 +1451,23 @@ void Session::itemVisibilitiesUpdated() {
 }
 
 void Session::notifyItemIdChange(IdChange event) {
-	const auto item = event.item;
+	const auto item = changeMessageId(
-	changeMessageId(item->history()->peer->id, event.oldId, item->id);
+		event.newId.peer,
+		event.oldId,
+		event.newId.msg);
 
 	_itemIdChanges.fire_copy(event);
 
-	const auto refreshViewDataId = [](not_null<ViewElement*> view) {
+	if (item) {
-		view->refreshDataId();
+		const auto refreshViewDataId = [](not_null<ViewElement*> view) {
-	};
+			view->refreshDataId();
-	enumerateItemViews(item, refreshViewDataId);
+		};
-	if (const auto group = groups().find(item)) {
+		enumerateItemViews(item, refreshViewDataId);
-		const auto leader = group->items.front();
+		if (const auto group = groups().find(item)) {
-		if (leader != item) {
+			const auto leader = group->items.front();
-			enumerateItemViews(leader, refreshViewDataId);
+			if (leader != item) {
+				enumerateItemViews(leader, refreshViewDataId);
+			}
 		}
 	}
 }

Telegram/SourceFiles/data/data_session.h

@@ -243,7 +243,7 @@ public:
 	void itemVisibilitiesUpdated();
 
 	struct IdChange {
-		not_null<HistoryItem*> item;
+		FullMsgId newId;
 		MsgId oldId = 0;
 	};
 	void notifyItemIdChange(IdChange event);
@@ -728,7 +728,7 @@ private:
 	not_null<Messages*> messagesListForInsert(PeerId peerId);
 	not_null<HistoryItem*> registerMessage(
 		std::unique_ptr<HistoryItem> item);
-	void changeMessageId(PeerId peerId, MsgId wasId, MsgId nowId);
+	HistoryItem *changeMessageId(PeerId peerId, MsgId wasId, MsgId nowId);
 	void removeDependencyMessage(not_null<HistoryItem*> item);
 
 	void photoApplyFields(

Telegram/SourceFiles/history/history_item.cpp

@@ -660,9 +660,11 @@ void HistoryItem::applySentMessage(const MTPDmessage &data) {
 	setForwardsCount(data.vforwards().value_or(-1));
 	if (const auto reply = data.vreply_to()) {
 		reply->match([&](const MTPDmessageReplyHeader &data) {
-			setReplyToTop(
+			setReplyFields(
+				data.vreply_to_msg_id().v,
 				data.vreply_to_top_id().value_or(
-					data.vreply_to_msg_id().v));
+					data.vreply_to_msg_id().v),
+				data.is_forum_topic());
 		});
 	}
 	setPostAuthor(data.vpost_author().value_or_empty());
@@ -715,7 +717,7 @@ void HistoryItem::setRealId(MsgId newId) {
 	if (isRegular()) {
 		_history->unregisterClientSideMessage(this);
 	}
-	_history->owner().notifyItemIdChange({ this, oldId });
+	_history->owner().notifyItemIdChange({ fullId(), oldId });
 
 	// We don't fire MessageUpdate::Flag::ReplyMarkup and update keyboard
 	// in history widget, because it can't exist for an outgoing message.

Telegram/SourceFiles/history/history_item.h

@@ -341,7 +341,10 @@ public:
 		PeerId replier,
 		std::optional<bool> unread) {
 	}
-	virtual void setReplyToTop(MsgId replyToTop) = 0;
+	virtual void setReplyFields(
+		MsgId replyTo,
+		MsgId replyToTop,
+		bool isForumPost) = 0;
 	virtual void setPostAuthor(const QString &author) {
 	}
 	virtual void setRealId(MsgId newId);

Telegram/SourceFiles/history/history_message.cpp

@@ -32,6 +32,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "data/data_media_types.h"
 #include "data/data_channel.h"
 #include "data/data_forum_topic.h"
+#include "data/data_forum.h"
 #include "data/data_user.h"
 #include "data/data_web_page.h"
 #include "data/data_sponsored_messages.h"
@@ -173,6 +174,9 @@ void RequestDependentMessageData(
 		not_null<HistoryItem*> item,
 		PeerId peerId,
 		MsgId msgId) {
+	if (!IsServerMsgId(msgId)) {
+		return;
+	}
 	const auto fullId = item->fullId();
 	const auto history = item->history();
 	const auto session = &history->session();
@@ -332,6 +336,7 @@ HistoryMessage::HistoryMessage(
 				: id;
 			config.replyToTop = data.vreply_to_top_id().value_or(
 				data.vreply_to_msg_id().v);
+			config.replyIsTopicPost = data.is_forum_topic();
 		});
 	}
 	config.viaBotId = data.vvia_bot_id().value_or_empty();
@@ -654,8 +659,10 @@ void HistoryMessage::createComponentsHelper(
 		const auto to = LookupReplyTo(history(), replyTo);
 		const auto replyToTop = LookupReplyToTop(to);
 		config.replyToTop = replyToTop ? replyToTop : replyTo;
+		const auto forum = history()->peer->forum();
 		config.replyIsTopicPost = LookupReplyIsTopicPost(to)
-			|| to->Has<HistoryServiceTopicInfo>();
+			|| (to && to->Has<HistoryServiceTopicInfo>())
+			|| (forum && forum->creating(replyToTop));
 	}
 	config.markup = std::move(markup);
 	if (flags & MessageFlag::HasPostAuthor) config.author = postAuthor;
@@ -1811,16 +1818,30 @@ void HistoryMessage::setSponsoredFrom(const Data::SponsoredFrom &from) {
 		: Type::Group;
 }
 
-void HistoryMessage::setReplyToTop(MsgId replyToTop) {
+void HistoryMessage::setReplyFields(
+		MsgId replyTo,
+		MsgId replyToTop,
+		bool isForumPost) {
 	const auto reply = Get<HistoryMessageReply>();
-	if (!reply
+	if (!reply || isScheduled()) {
-		|| (reply->replyToMsgTop == replyToTop)
-		|| (reply->replyToMsgTop != 0)
-		|| isScheduled()) {
 		return;
 	}
-	reply->replyToMsgTop = replyToTop;
+	reply->topicPost = isForumPost;
-	changeReplyToTopCounter(reply, 1);
+	if ((reply->replyToMsgId != replyTo)
+		&& !IsServerMsgId(reply->replyToMsgId)) {
+		reply->replyToMsgId = replyTo;
+		if (!reply->updateData(this)) {
+			RequestDependentMessageData(
+				this,
+				reply->replyToPeerId,
+				reply->replyToMsgId);
+		}
+	}
+	if ((reply->replyToMsgTop != replyToTop)
+		&& !IsServerMsgId(reply->replyToMsgTop)) {
+		reply->replyToMsgTop = replyToTop;
+		changeReplyToTopCounter(reply, 1);
+	}
 }
 
 void HistoryMessage::setRealId(MsgId newId) {

Telegram/SourceFiles/history/history_message.h

@@ -146,7 +146,10 @@ public:
 		int delta,
 		PeerId replier,
 		std::optional<bool> unread) override;
-	void setReplyToTop(MsgId replyToTop) override;
+	void setReplyFields(
+		MsgId replyTo,
+		MsgId replyToTop,
+		bool isForumPost) override;
 	void setPostAuthor(const QString &author) override;
 	void setRealId(MsgId newId) override;
 	void incrementReplyToTopCounter() override;

Telegram/SourceFiles/history/history_service.cpp

@@ -1318,12 +1318,12 @@ MsgId HistoryService::topicRootId() const {
 	return Data::ForumTopic::kGeneralId;
 }
 
-void HistoryService::setReplyToTop(MsgId replyToTop) {
+void HistoryService::setReplyFields(
+		MsgId replyTo,
+		MsgId replyToTop,
+		bool isForumPost) {
 	const auto data = GetDependentData();
-	if (!data
+	if (!data || IsServerMsgId(data->topId) || isScheduled()) {
-		|| (data->topId == replyToTop)
-		|| (data->topId != 0)
-		|| isScheduled()) {
 		return;
 	}
 	data->topId = replyToTop;

Telegram/SourceFiles/history/history_service.h

@@ -139,7 +139,10 @@ public:
 	MsgId replyToId() const override;
 	MsgId replyToTop() const override;
 	MsgId topicRootId() const override;
-	void setReplyToTop(MsgId replyToTop) override;
+	void setReplyFields(
+		MsgId replyTo,
+		MsgId replyToTop,
+		bool isForumPost) override;
 
 	std::unique_ptr<HistoryView::Element> createView(
 		not_null<HistoryView::ElementDelegate*> delegate,

Telegram/SourceFiles/history/view/history_view_replies_section.cpp

@@ -154,6 +154,16 @@ object_ptr<Window::SectionWidget> RepliesMemento::createWidget(
 	return result;
 }
 
+void RepliesMemento::setupTopicViewer() {
+	_history->owner().itemIdChanged(
+	) | rpl::start_with_next([=](const Data::Session::IdChange &change) {
+		if (_rootId == change.oldId) {
+			_rootId = change.newId.msg;
+			_replies = nullptr;
+		}
+	}, _lifetime);
+}
+
 RepliesWidget::RepliesWidget(
 	QWidget *parent,
 	not_null<Window::SessionController*> controller,
@@ -199,6 +209,7 @@ RepliesWidget::RepliesWidget(
 
 	setupRoot();
 	setupRootView();
+	setupTopicViewer();
 
 	session().api().requestFullPeer(_history->peer);
 
@@ -442,6 +453,27 @@ void RepliesWidget::setupRootView() {
 	}, _rootView->lifetime());
 }
 
+void RepliesWidget::setupTopicViewer() {
+	_history->owner().itemIdChanged(
+	) | rpl::start_with_next([=](const Data::Session::IdChange &change) {
+		if (_rootId == change.oldId) {
+			_rootId = change.newId.msg;
+			_root = lookupRoot();
+			createReplies();
+			if (_topic && _topic->rootId() == change.oldId) {
+				setTopic(_topic->forum()->topicFor(change.newId.msg));
+			}
+			_inner->update();
+		}
+	}, lifetime());
+}
+
+void RepliesWidget::setTopic(Data::ForumTopic *topic) {
+	if ((_topic = topic)) {
+		refreshTopBarActiveChat();
+	}
+}
+
 HistoryItem *RepliesWidget::lookupRoot() const {
 	return _history->owner().message(_history->peer, _rootId);
 }
@@ -458,9 +490,7 @@ Data::ForumTopic *RepliesWidget::lookupTopic() {
 			).done([=](const MTPmessages_ForumTopics &result) {
 				if (const auto forum = _history->peer->forum()) {
 					forum->applyReceivedTopics(result);
-					if ((_topic = forum->topicFor(_rootId))) {
+					setTopic(forum->topicFor(_rootId));
-						refreshTopBarActiveChat();
-					}
 				}
 				_resolveTopicRequestId = 0;
 			}).fail([=] {
@@ -1699,32 +1729,44 @@ void RepliesWidget::saveState(not_null<RepliesMemento*> memento) {
 	_inner->saveState(memento->list());
 }
 
-void RepliesWidget::restoreState(not_null<RepliesMemento*> memento) {
+void RepliesWidget::createReplies() {
-	const auto setReplies = [&](std::shared_ptr<Data::RepliesList> replies) {
+	auto old = base::take(_replies);
-		_replies = std::move(replies);
+	setReplies(std::make_shared<Data::RepliesList>(_history, _rootId));
+	if (old) {
+		_inner->showAroundPosition(Data::UnreadMessagePosition, nullptr);
+	}
+}
 
-		rpl::combine(
+void RepliesWidget::setReplies(std::shared_ptr<Data::RepliesList> replies) {
-			rpl::single(0) | rpl::then(_replies->fullCount()),
+	_replies = std::move(replies);
-			_areComments.value()
+	_repliesLifetime.destroy();
-		) | rpl::map([=](int count, bool areComments) {
+	if (_topic) {
-			return count
+		return;
-				? (areComments
+	}
-					? tr::lng_comments_header
+	rpl::combine(
-					: tr::lng_replies_header)(
+		rpl::single(0) | rpl::then(_replies->fullCount()),
-						lt_count_decimal,
+		_areComments.value()
-						rpl::single(count) | tr::to_count())
+	) | rpl::map([=](int count, bool areComments) {
-				: (areComments
+		return count
-					? tr::lng_comments_header_none
+			? (areComments
-					: tr::lng_replies_header_none)();
+				? tr::lng_comments_header
-		}) | rpl::flatten_latest(
+				: tr::lng_replies_header)(
-		) | rpl::start_with_next([=](const QString &text) {
+					lt_count_decimal,
-			_topBar->setCustomTitle(text);
+					rpl::single(count) | tr::to_count())
-		}, lifetime());
+			: (areComments
-	};
+				? tr::lng_comments_header_none
+				: tr::lng_replies_header_none)();
+	}) | rpl::flatten_latest(
+	) | rpl::start_with_next([=](const QString &text) {
+		_topBar->setCustomTitle(text);
+	}, _repliesLifetime);
+}
+
+void RepliesWidget::restoreState(not_null<RepliesMemento*> memento) {
 	if (auto replies = memento->getReplies()) {
 		setReplies(std::move(replies));
 	} else if (!_replies) {
-		setReplies(std::make_shared<Data::RepliesList>(_history, _rootId));
+		createReplies();
 	}
 	restoreReplyReturns(memento->replyReturns());
 	_inner->restoreState(memento->list());

Telegram/SourceFiles/history/view/history_view_replies_section.h

@@ -163,6 +163,8 @@ private:
 	void updateAdaptiveLayout();
 	void saveState(not_null<RepliesMemento*> memento);
 	void restoreState(not_null<RepliesMemento*> memento);
+	void setReplies(std::shared_ptr<Data::RepliesList> replies);
+	void createReplies();
 	void showAtStart();
 	void showAtEnd();
 	void showAtPosition(
@@ -178,6 +180,8 @@ private:
 
 	void setupRoot();
 	void setupRootView();
+	void setupTopicViewer();
+	void setTopic(Data::ForumTopic *topic);
 	void setupDragArea();
 	void sendReadTillRequest();
 	void readTill(not_null<HistoryItem*> item);
@@ -276,6 +280,7 @@ private:
 	mutable bool _newTopicDiscarded = false;
 
 	std::shared_ptr<Data::RepliesList> _replies;
+	rpl::lifetime _repliesLifetime;
 	rpl::variable<bool> _areComments = false;
 	std::shared_ptr<SendActionPainter> _sendAction;
 	QPointer<ListWidget> _inner;
@@ -363,13 +368,17 @@ public:
 	}
 
 private:
+	void setupTopicViewer();
+
 	const not_null<History*> _history;
-	const MsgId _rootId = 0;
+	MsgId _rootId = 0;
 	const MsgId _highlightId = 0;
 	ListMemento _list;
 	std::shared_ptr<Data::RepliesList> _replies;
 	std::vector<MsgId> _replyReturns;
 
+	rpl::lifetime _lifetime;
+
 };
 
 } // namespace HistoryView

Telegram/SourceFiles/info/info_content_widget.cpp

@@ -24,6 +24,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "data/data_channel.h"
 #include "data/data_session.h"
 #include "data/data_forum_topic.h"
+#include "data/data_forum.h"
 #include "main/main_session.h"
 #include "styles/style_info.h"
 #include "styles/style_profile.h"
@@ -340,6 +341,12 @@ ContentMemento::ContentMemento(not_null<Data::ForumTopic*> topic)
 : _peer(topic->channel())
 , _migratedPeerId(_peer->migrateFrom() ? _peer->migrateFrom()->id : 0)
 , _topic(topic) {
+	_peer->owner().itemIdChanged(
+	) | rpl::start_with_next([=](const Data::Session::IdChange &change) {
+		if (_topic->rootId() == change.oldId) {
+			_topic = _topic->forum()->topicFor(change.newId.msg);
+		}
+	}, _lifetime);
 }
 
 ContentMemento::ContentMemento(Settings::Tag settings)

Telegram/SourceFiles/info/info_content_widget.h

@@ -213,7 +213,7 @@ public:
 private:
 	PeerData * const _peer = nullptr;
 	const PeerId _migratedPeerId = 0;
-	Data::ForumTopic * const _topic = nullptr;
+	Data::ForumTopic *_topic = nullptr;
 	UserData * const _settingsSelf = nullptr;
 	PollData * const _poll = nullptr;
 	const FullMsgId _pollContextId;
@@ -223,6 +223,8 @@ private:
 	bool _searchEnabledByContent = false;
 	bool _searchStartsFocused = false;
 
+	rpl::lifetime _lifetime;
+
 };
 
 } // namespace Info

Telegram/SourceFiles/info/info_controller.cpp

@@ -18,6 +18,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "data/data_channel.h"
 #include "data/data_chat.h"
 #include "data/data_forum_topic.h"
+#include "data/data_forum.h"
 #include "data/data_session.h"
 #include "data/data_media_types.h"
 #include "data/data_download_manager.h"
@@ -180,6 +181,7 @@ Controller::Controller(
 , _section(memento->section()) {
 	updateSearchControllers(memento);
 	setupMigrationViewer();
+	setupTopicViewer();
 }
 
 void Controller::setupMigrationViewer() {
@@ -210,6 +212,17 @@ void Controller::setupMigrationViewer() {
 	}, lifetime());
 }
 
+void Controller::setupTopicViewer() {
+	session().data().itemIdChanged(
+	) | rpl::start_with_next([=](const Data::Session::IdChange &change) {
+		if (const auto topic = _key.topic()) {
+			if (topic->rootId() == change.oldId) {
+				_key = Key(topic->forum()->topicFor(change.newId.msg));
+			}
+		}
+	}, _lifetime);
+}
+
 Wrap Controller::wrap() const {
 	return _widget->wrap();
 }

Telegram/SourceFiles/info/info_controller.h

@@ -235,6 +235,7 @@ private:
 	void updateSearchControllers(not_null<ContentMemento*> memento);
 	SearchQuery produceSearchQuery(const QString &query) const;
 	void setupMigrationViewer();
+	void setupTopicViewer();
 
 	not_null<WrapWidget*> _widget;
 	Key _key;

Telegram/SourceFiles/info/media/info_media_widget.h

@@ -28,7 +28,7 @@ class Memento final : public ContentMemento {
 public:
 	explicit Memento(not_null<Controller*> controller);
 	Memento(not_null<PeerData*> peer, PeerId migratedPeerId, Type type);
-	Memento(not_null<Data::ForumTopic*> peer, Type type);
+	Memento(not_null<Data::ForumTopic*> topic, Type type);
 
 	using SearchState = Api::DelayedSearchController::SavedState;
 

Telegram/SourceFiles/media/view/media_view_overlay_widget.cpp

@@ -702,8 +702,8 @@ void OverlayWidget::documentUpdated(not_null<DocumentData*> document) {
 	}
 }
 
-void OverlayWidget::changingMsgId(not_null<HistoryItem*> row, MsgId oldId) {
+void OverlayWidget::changingMsgId(FullMsgId newId, MsgId oldId) {
-	if (row == _message) {
+	if (_message && _message->fullId() == newId) {
 		refreshMediaViewer();
 	}
 }
@@ -4181,7 +4181,7 @@ void OverlayWidget::setSession(not_null<Main::Session*> session) {
 
 	session->data().itemIdChanged(
 	) | rpl::start_with_next([=](const Data::Session::IdChange &change) {
-		changingMsgId(change.item, change.oldId);
+		changingMsgId(change.newId, change.oldId);
 	}, _sessionLifetime);
 
 	session->data().itemRemoved(

Telegram/SourceFiles/media/view/media_view_overlay_widget.h

@@ -330,7 +330,7 @@ private:
 	void updateThemePreviewGeometry();
 
 	void documentUpdated(not_null<DocumentData*> document);
-	void changingMsgId(not_null<HistoryItem*> row, MsgId oldId);
+	void changingMsgId(FullMsgId newId, MsgId oldId);
 
 	[[nodiscard]] int finalContentRotation() const;
 	[[nodiscard]] QRect finalContentRect() const;

Telegram/SourceFiles/ui/chat/attach/attach_album_thumbnail.cpp

@@ -68,7 +68,7 @@ AlbumThumbnail::AlbumThumbnail(
 
 	const auto availableFileWidth = st::sendMediaPreviewSize
 		- st.thumbSize
-		- st.padding.right()
+		- st.thumbSkip
 		// Right buttons.
 		- st::sendBoxAlbumGroupButtonFile.width * 2
 		- st::sendBoxAlbumGroupEditInternalSkip * 2
@@ -392,7 +392,7 @@ void AlbumThumbnail::paintFile(
 		int top,
 		int outerWidth) {
 	const auto &st = st::attachPreviewThumbLayout;
-	const auto textLeft = left + st.thumbSize + st.padding.right();
+	const auto textLeft = left + st.thumbSize + st.thumbSkip;
 
 	p.drawPixmap(left, top, _fileThumb);
 	p.setFont(st::semiboldFont);

Telegram/SourceFiles/window/window_session_controller.cpp

@@ -39,6 +39,8 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "data/data_document_resolver.h"
 #include "data/data_changes.h"
 #include "data/data_group_call.h"
+#include "data/data_forum.h"
+#include "data/data_forum_topic.h"
 #include "data/data_chat_filters.h"
 #include "data/data_peer_values.h"
 #include "passport/passport_form_controller.h"
@@ -674,6 +676,27 @@ SessionController::SessionController(
 		});
 	}, lifetime());
 
+	session->data().itemIdChanged(
+	) | rpl::start_with_next([=](Data::Session::IdChange change) {
+		const auto current = _activeChatEntry.current();
+		if (const auto topic = current.key.topic()) {
+			if (topic->rootId() == change.oldId) {
+				setActiveChatEntry({
+					Dialogs::Key(topic->forum()->topicFor(change.newId.msg)),
+					current.fullId,
+				});
+			}
+		}
+		for (auto &entry : _chatEntryHistory) {
+			if (const auto topic = entry.key.topic()) {
+				if (topic->rootId() == change.oldId) {
+					entry.key = Dialogs::Key(
+						topic->forum()->topicFor(change.newId.msg));
+				}
+			}
+		}
+	}, lifetime());
+
 	session->api().globalPrivacy().suggestArchiveAndMute(
 	) | rpl::take(1) | rpl::start_with_next([=] {
 		session->api().globalPrivacy().reload(crl::guard(this, [=] {