Fix crash in topics disabling.

Telegram/SourceFiles/history/view/history_view_pinned_section.cpp

@@ -84,6 +84,10 @@ object_ptr<Window::SectionWidget> PinnedMemento::createWidget(
 	return result;
 }
 
+Data::ForumTopic *PinnedMemento::topicForRemoveRequests() const {
+	return _thread->asTopic();
+}
+
 PinnedWidget::PinnedWidget(
 	QWidget *parent,
 	not_null<Window::SessionController*> controller,

Telegram/SourceFiles/history/view/history_view_pinned_section.h

@@ -210,6 +210,8 @@ public:
 		return _highlightId;
 	}
 
+	Data::ForumTopic *topicForRemoveRequests() const override;
+
 private:
 	const not_null<Data::Thread*> _thread;
 	const UniversalMsgId _highlightId = 0;

Telegram/SourceFiles/history/view/history_view_replies_section.cpp

@@ -153,6 +153,11 @@ void RepliesMemento::setFromTopic(not_null<Data::ForumTopic*> topic) {
 	}
 }
 
+
+Data::ForumTopic *RepliesMemento::topicForRemoveRequests() const {
+	return _history->peer->forumTopicFor(_rootId);
+}
+
 void RepliesMemento::setReadInformation(
 		MsgId inboxReadTillId,
 		int unreadCount,

Telegram/SourceFiles/history/view/history_view_replies_section.h

@@ -408,6 +408,8 @@ public:
 		return _replyReturns;
 	}
 
+	Data::ForumTopic *topicForRemoveRequests() const override;
+
 	[[nodiscard]] not_null<ListMemento*> list() {
 		return &_list;
 	}

Telegram/SourceFiles/info/info_wrap_widget.h

@@ -112,8 +112,6 @@ public:
 
 	rpl::producer<int> desiredHeightValue() const override;
 
-	void updateInternalState(not_null<Memento*> memento);
-
 	// Float player interface.
 	bool floatPlayerHandleWheelEvent(QEvent *e) override;
 	QRect floatPlayerAvailableRect() override;

Telegram/SourceFiles/mainwidget.cpp

@@ -13,6 +13,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "data/data_document.h"
 #include "data/data_document_media.h"
 #include "data/data_document_resolver.h"
+#include "data/data_forum_topic.h"
 #include "data/data_wall_paper.h"
 #include "data/data_web_page.h"
 #include "data/data_game.h"
@@ -150,13 +151,20 @@ public:
 	}
 
 	[[nodiscard]] virtual StackItemType type() const = 0;
-	[[nodiscard]] virtual rpl::producer<> removeRequests() const = 0;
+	[[nodiscard]] rpl::producer<> removeRequests() const {
+		return rpl::merge(
+			_thirdSectionRemoveRequests.events(),
+			sectionRemoveRequests());
+	}
 	virtual ~StackItem() = default;
 
 private:
+	[[nodiscard]] virtual rpl::producer<> sectionRemoveRequests() const = 0;
+
 	PeerData *_peer = nullptr;
 	QPointer<Window::SectionWidget> _thirdSectionWeak;
 	std::shared_ptr<Window::SectionMemento> _thirdSectionMemento;
+	rpl::event_stream<> _thirdSectionRemoveRequests;
 
 	rpl::lifetime _lifetime;
 
@@ -177,14 +185,16 @@ public:
 	StackItemType type() const override {
 		return HistoryStackItem;
 	}
-	rpl::producer<> removeRequests() const override {
-		return rpl::never<>();
-	}
 
 	not_null<History*> history;
 	MsgId msgId;
 	QVector<FullMsgId> replyReturns;
 
+private:
+	rpl::producer<> sectionRemoveRequests() const override {
+		return rpl::never<>();
+	}
+
 };
 
 class StackItemSection : public StackItem {
@@ -195,14 +205,13 @@ public:
 	StackItemType type() const override {
 		return SectionStackItem;
 	}
-	rpl::producer<> removeRequests() const override {
-		return _memento->removeRequests();
-	}
 	std::shared_ptr<Window::SectionMemento> takeMemento() {
 		return std::move(_memento);
 	}
 
 private:
+	rpl::producer<> sectionRemoveRequests() const override;
+
 	std::shared_ptr<Window::SectionMemento> _memento;
 
 };
@@ -210,6 +219,10 @@ private:
 void StackItem::setThirdSectionMemento(
 		std::shared_ptr<Window::SectionMemento> memento) {
 	_thirdSectionMemento = std::move(memento);
+	if (const auto memento = _thirdSectionMemento.get()) {
+		memento->removeRequests(
+		) | rpl::start_to_stream(_thirdSectionRemoveRequests, _lifetime);
+	}
 }
 
 StackItemSection::StackItemSection(
@@ -218,6 +231,13 @@ StackItemSection::StackItemSection(
 , _memento(std::move(memento)) {
 }
 
+rpl::producer<> StackItemSection::sectionRemoveRequests() const {
+	if (const auto topic = _memento->topicForRemoveRequests()) {
+		return rpl::merge(_memento->removeRequests(), topic->destroyed());
+	}
+	return _memento->removeRequests();
+}
+
 struct MainWidget::SettingBackground {
 	explicit SettingBackground(const Data::WallPaper &data);
 

Telegram/SourceFiles/window/section_memento.h

@@ -11,6 +11,10 @@ namespace Ui {
 class LayerWidget;
 } // namespace Ui
 
+namespace Data {
+class ForumTopic;
+} // namespace Data
+
 namespace Window {
 
 class SessionController;
@@ -34,6 +38,9 @@ public:
 		return false;
 	}
 
+	[[nodiscard]] virtual Data::ForumTopic *topicForRemoveRequests() const {
+		return nullptr;
+	}
 	[[nodiscard]] virtual rpl::producer<> removeRequests() const {
 		return rpl::never<>();
 	}

Telegram/SourceFiles/window/window_session_controller.cpp

@@ -1001,10 +1001,16 @@ void SessionController::showForum(
 	}
 	forum->destroyed(
 	) | rpl::start_with_next([=, history = forum->history()] {
+		const auto now = activeChatCurrent().owningHistory();
+		const auto showHistory = !now || (now == history);
 		closeForum();
-		showPeerHistory(
-			history,
-			{ anim::type::normal, anim::activation::background });
+		if (showHistory) {
+			showPeerHistory(history, {
+				SectionShow::Way::Backward,
+				anim::type::normal,
+				anim::activation::background,
+			});
+		}
 	}, _shownForumLifetime);
 	content()->showForum(forum, params);
 }