Attempt to fix a couple of crashes.

Telegram/SourceFiles/core/application.cpp

@@ -1527,14 +1527,14 @@ void Application::closeChatFromWindows(not_null<PeerData*> peer) {
 		}
 	}
 	if (const auto window = windowFor(&peer->account())) {
-		const auto primary = window->sessionController();
+		if (const auto primary = window->sessionController()) {
-		if ((primary->activeChatCurrent().peer() == peer)
+			if (primary->activeChatCurrent().peer() == peer) {
-			&& (&primary->session() == &peer->session())) {
+				primary->clearSectionStack();
-			primary->clearSectionStack();
+			}
-		}
+			if (const auto forum = primary->shownForum().current()) {
-		if (const auto forum = primary->shownForum().current()) {
+				if (peer->forum() == forum) {
-			if (peer->forum() == forum) {
+					primary->closeForum();
-				primary->closeForum();
+				}
 			}
 		}
 	}

Telegram/SourceFiles/history/history_widget.cpp

@@ -810,7 +810,7 @@ HistoryWidget::HistoryWidget(
 				const auto account = &_peer->account();
 				closeCurrent();
 				if (const auto primary = Core::App().windowFor(account)) {
-					controller->showToast(unavailable);
+					primary->showToast(unavailable);
 				}
 				return;
 			}
@@ -3316,7 +3316,7 @@ void HistoryWidget::messagesFailed(const MTP::Error &error, int requestId) {
 		auto was = _peer;
 		closeCurrent();
 		if (const auto primary = Core::App().windowFor(&was->account())) {
-			controller()->showToast((was && was->isMegagroup())
+			primary->showToast((was && was->isMegagroup())
 				? tr::lng_group_not_accessible(tr::now)
 				: tr::lng_channel_not_accessible(tr::now));
 		}

Telegram/SourceFiles/iv/iv_instance.cpp

@@ -980,20 +980,16 @@ void Instance::processOpenChannel(const QString &context) {
 	} else if (const auto channelId = ChannelId(context.toLongLong())) {
 		const auto channel = _shownSession->data().channel(channelId);
 		if (channel->isLoaded()) {
-			if (const auto window = Core::App().windowFor(channel)) {
+			if (const auto controller = _shownSession->tryResolveWindow(channel)) {
-				if (const auto controller = window->sessionController()) {
+				controller->showPeerHistory(channel);
-					controller->showPeerHistory(channel);
+				_shown = nullptr;
-					_shown = nullptr;
-				}
 			}
 		} else if (!channel->username().isEmpty()) {
-			if (const auto window = Core::App().windowFor(channel)) {
+			if (const auto controller = _shownSession->tryResolveWindow(channel)) {
-				if (const auto controller = window->sessionController()) {
+				controller->showPeerByLink({
-					controller->showPeerByLink({
+					.usernameOrId = channel->username(),
-						.usernameOrId = channel->username(),
+				});
-					});
+				_shown = nullptr;
-					_shown = nullptr;
-				}
 			}
 		}
 	}
@@ -1008,13 +1004,11 @@ void Instance::processJoinChannel(const QString &context) {
 		if (channel->isLoaded()) {
 			_shownSession->api().joinChannel(channel);
 		} else if (!channel->username().isEmpty()) {
-			if (const auto window = Core::App().windowFor(channel)) {
+			if (const auto controller = _shownSession->tryResolveWindow(channel)) {
-				if (const auto controller = window->sessionController()) {
+				controller->showPeerByLink({
-					controller->showPeerByLink({
+					.usernameOrId = channel->username(),
-						.usernameOrId = channel->username(),
+					.joinChannel = true,
-						.joinChannel = true,
+				});
-					});
-				}
 			}
 		}
 	}

Telegram/SourceFiles/main/main_session.cpp

@@ -434,6 +434,10 @@ void Session::uploadsStopWithConfirmation(Fn<void()> done) {
 	const auto window = message
 		? Core::App().windowFor(message->history()->peer)
 		: Core::App().activePrimaryWindow();
+	if (!window) {
+		done();
+		return;
+	}
 	auto box = Box([=](not_null<Ui::GenericBox*> box) {
 		box->addRow(
 			object_ptr<Ui::FlatLabel>(
@@ -476,8 +480,22 @@ auto Session::windows() const
 	return _windows;
 }
 
-Window::SessionController *Session::tryResolveWindow() const {
+Window::SessionController *Session::tryResolveWindow(
-	if (_windows.empty()) {
+		PeerData *forPeer) const {
+	if (forPeer) {
+		auto primary = (Window::SessionController*)nullptr;
+		for (const auto &window : _windows) {
+			if (window->singlePeer() == forPeer) {
+				return window;
+			} else if (window->isPrimary()) {
+				primary = window;
+			}
+		}
+		if (primary) {
+			return primary;
+		}
+	}
+	if (_windows.empty() || forPeer) {
 		domain().activate(_account);
 		if (_windows.empty()) {
 			return nullptr;

Telegram/SourceFiles/main/main_session.h

@@ -164,7 +164,8 @@ public:
 	void addWindow(not_null<Window::SessionController*> controller);
 	[[nodiscard]] auto windows() const
 		-> const base::flat_set<not_null<Window::SessionController*>> &;
-	[[nodiscard]] Window::SessionController *tryResolveWindow() const;
+	[[nodiscard]] Window::SessionController *tryResolveWindow(
+		PeerData *forPeer = nullptr) const;
 
 	// Shortcuts.
 	void notifyDownloaderTaskFinished();

Telegram/SourceFiles/media/stories/media_stories_controller.cpp

@@ -1891,16 +1891,12 @@ ClickHandlerPtr MakeChannelPostHandler(
 		FullMsgId item) {
 	return std::make_shared<LambdaClickHandler>(crl::guard(session, [=] {
 		const auto peer = session->data().peer(item.peer);
-		if (const auto window = Core::App().windowFor(peer)) {
+		if (const auto controller = session->tryResolveWindow(peer)) {
-			if (const auto controller = window->sessionController()) {
+			Core::App().hideMediaView();
-				if (&controller->session() == &peer->session()) {
+			controller->showPeerHistory(
-					Core::App().hideMediaView();
+				peer,
-					controller->showPeerHistory(
+				Window::SectionShow::Way::ClearStack,
-						item.peer,
+				item.msg);
-						Window::SectionShow::Way::ClearStack,
-						item.msg);
-				}
-			}
 		}
 	}));
 }