Fix crash in session destruction.

Also use rpl::event_stream for downloaderTaskFinished.

Telegram/SourceFiles/boxes/add_contact_box.cpp

@@ -1364,7 +1364,10 @@ void RevokePublicLinkBox::prepare() {
 
 	addButton(tr::lng_cancel(), [=] { closeBox(); });
 
-	subscribe(_session->downloaderTaskFinished(), [=] { update(); });
+	_session->downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
+		update();
+	}, lifetime());
 
 	_inner->resizeToWidth(st::boxWideWidth);
 	setDimensions(st::boxWideWidth, _innerTop + _inner->height());

Telegram/SourceFiles/boxes/background_box.cpp

@@ -203,7 +203,10 @@ BackgroundBox::Inner::Inner(
 	}
 	requestPapers();
 
-	subscribe(_session->downloaderTaskFinished(), [=] { update(); });
+	_session->downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
+		update();
+	}, lifetime());
 	using Update = Window::Theme::BackgroundUpdate;
 	subscribe(Window::Theme::Background(), [=](const Update &update) {
 		if (update.paletteChanged()) {

Telegram/SourceFiles/boxes/background_preview_box.cpp

@@ -419,9 +419,10 @@ BackgroundPreviewBox::BackgroundPreviewBox(
 	if (_media) {
 		_media->thumbnailWanted(_paper.fileOrigin());
 	}
-	subscribe(_controller->session().downloaderTaskFinished(), [=] {
+	_controller->session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
 		update();
-	});
+	}, lifetime());
 }
 
 not_null<HistoryView::ElementDelegate*> BackgroundPreviewBox::delegate() {

Telegram/SourceFiles/boxes/confirm_box.cpp

@@ -891,9 +891,10 @@ ConfirmInviteBox::ConfirmInviteBox(
 		_photo = photo->createMediaView();
 		_photo->wanted(Data::PhotoSize::Small, Data::FileOrigin());
 		if (!_photo->image(Data::PhotoSize::Small)) {
-			subscribe(_session->downloaderTaskFinished(), [=] {
+			_session->downloaderTaskFinished(
+			) | rpl::start_with_next([=] {
 				update();
-			});
+			}, lifetime());
 		}
 	} else {
 		_photoEmpty = std::make_unique<Ui::EmptyUserpic>(

Telegram/SourceFiles/boxes/edit_caption_box.cpp

@@ -291,7 +291,8 @@ EditCaptionBox::EditCaptionBox(
 	Assert(_thumbnailImageLoaded || _refreshThumbnail);
 
 	if (!_thumbnailImageLoaded) {
-		subscribe(_controller->session().downloaderTaskFinished(), [=] {
+		_controller->session().downloaderTaskFinished(
+		) | rpl::start_with_next([=] {
 			if (_thumbnailImageLoaded
 				|| (_photoMedia && !_photoMedia->image(PhotoSize::Large))
 				|| (_documentMedia && !_documentMedia->thumbnail())) {
@@ -299,7 +300,7 @@ EditCaptionBox::EditCaptionBox(
 			}
 			_refreshThumbnail();
 			update();
-		});
+		}, lifetime());
 	}
 	_field.create(
 		this,

Telegram/SourceFiles/boxes/peer_list_box.cpp

@@ -662,9 +662,10 @@ PeerListContent::PeerListContent(
 , _st(st)
 , _controller(controller)
 , _rowHeight(_st.item.height) {
-	subscribe(_controller->session().downloaderTaskFinished(), [=] {
+	_controller->session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
 		update();
-	});
+	}, lifetime());
 
 	using UpdateFlag = Data::PeerUpdate::Flag;
 	_controller->session().changes().peerUpdates(

Telegram/SourceFiles/boxes/share_box.cpp

@@ -570,9 +570,10 @@ ShareBox::Inner::Inner(
 			update.oldFirstLetters);
 	}, lifetime());
 
-	subscribe(_navigation->session().downloaderTaskFinished(), [=] {
+	_navigation->session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
 		update();
-	});
+	}, lifetime());
 
 	subscribe(Window::Theme::Background(), [this](const Window::Theme::BackgroundUpdate &update) {
 		if (update.paletteChanged()) {

Telegram/SourceFiles/boxes/sticker_set_box.cpp

@@ -254,7 +254,10 @@ StickerSetBox::Inner::Inner(
 
 	_controller->session().api().updateStickers();
 
-	subscribe(_controller->session().downloaderTaskFinished(), [this] { update(); });
+	_controller->session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
+		update();
+	}, lifetime());
 
 	setMouseTracking(true);
 }

Telegram/SourceFiles/boxes/stickers_box.cpp

@@ -1002,10 +1002,12 @@ Main::Session &StickersBox::Inner::session() const {
 }
 
 void StickersBox::Inner::setup() {
-	subscribe(session().downloaderTaskFinished(), [this] {
+	session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
 		update();
 		readVisibleSets();
-	});
+	}, lifetime());
+
 	setMouseTracking(true);
 }
 

Telegram/SourceFiles/calls/calls_panel.cpp

@@ -446,9 +446,10 @@ void Panel::initLayout() {
 	}, lifetime());
 	processUserPhoto();
 
-	subscribe(_user->session().downloaderTaskFinished(), [=] {
+	_user->session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
 		refreshUserPhoto();
-	});
+	}, lifetime());
 	createDefaultCacheImage();
 
 	Ui::Platform::InitOnTopPanel(this);

Telegram/SourceFiles/chat_helpers/field_autocomplete.cpp

@@ -604,9 +604,10 @@ FieldAutocompleteInner::FieldAutocompleteInner(
 , _brows(brows)
 , _srows(srows)
 , _previewTimer([=] { showPreview(); }) {
-	subscribe(
-		controller->session().downloaderTaskFinished(),
-		[=] { update(); });
+	controller->session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
+		update();
+	}, lifetime());
 }
 
 void FieldAutocompleteInner::paintEvent(QPaintEvent *e) {

Telegram/SourceFiles/chat_helpers/gifs_list_widget.cpp

@@ -153,9 +153,10 @@ GifsListWidget::GifsListWidget(
 		refreshSavedGifs();
 	}, lifetime());
 
-	subscribe(controller->session().downloaderTaskFinished(), [this] {
+	controller->session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
 		update();
-	});
+	}, lifetime());
 
 	subscribe(controller->gifPauseLevelChanged(), [=] {
 		if (!controller->isGifPausedAtLeastFor(

Telegram/SourceFiles/chat_helpers/stickers_emoji_pack.cpp

@@ -198,7 +198,7 @@ std::shared_ptr<LargeEmojiImage> EmojiPack::image(EmojiPtr emoji) {
 						if (!strong->image) {
 							strong->load = nullptr;
 							strong->image.emplace(std::move(image));
-							_session->downloaderTaskFinished().notify();
+							_session->notifyDownloaderTaskFinished();
 						}
 					}
 				}

Telegram/SourceFiles/chat_helpers/stickers_list_widget.cpp

@@ -105,9 +105,7 @@ struct StickerIcon {
 
 };
 
-class StickersListWidget::Footer
-	: public TabbedSelector::InnerFooter
-	, private base::Subscriber {
+class StickersListWidget::Footer : public TabbedSelector::InnerFooter {
 public:
 	explicit Footer(not_null<StickersListWidget*> parent);
 
@@ -132,7 +130,7 @@ protected:
 	void mousePressEvent(QMouseEvent *e) override;
 	void mouseMoveEvent(QMouseEvent *e) override;
 	void mouseReleaseEvent(QMouseEvent *e) override;
-	bool event(QEvent *e) override;
+	bool eventHook(QEvent *e) override;
 
 	void processHideFinished() override;
 
@@ -249,9 +247,10 @@ StickersListWidget::Footer::Footer(not_null<StickersListWidget*> parent)
 
 	_iconsLeft = _iconsRight = st::emojiCategorySkip + st::stickerIconWidth;
 
-	subscribe(_pan->session().downloaderTaskFinished(), [=] {
+	_pan->session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
 		update();
-	});
+	}, lifetime());
 }
 
 void StickersListWidget::Footer::clearHeavyData() {
@@ -600,7 +599,7 @@ void StickersListWidget::Footer::finishDragging() {
 	updateSelected();
 }
 
-bool StickersListWidget::Footer::event(QEvent *e) {
+bool StickersListWidget::Footer::eventHook(QEvent *e) {
 	if (e->type() == QEvent::TouchBegin) {
 	} else if (e->type() == QEvent::Wheel) {
 		if (!_icons.empty()
@@ -609,7 +608,7 @@ bool StickersListWidget::Footer::event(QEvent *e) {
 			scrollByWheelEvent(static_cast<QWheelEvent*>(e));
 		}
 	}
-	return InnerFooter::event(e);
+	return InnerFooter::eventHook(e);
 }
 
 void StickersListWidget::Footer::scrollByWheelEvent(
@@ -890,12 +889,13 @@ StickersListWidget::StickersListWidget(
 			Box<StickersBox>(controller, StickersBox::Section::Installed));
 	});
 
-	subscribe(session().downloaderTaskFinished(), [=] {
+	session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
 		if (isVisible()) {
 			update();
 			readVisibleFeatured(getVisibleTop(), getVisibleBottom());
 		}
-	});
+	}, lifetime());
 
 	session().changes().peerUpdates(
 		Data::PeerUpdate::Flag::StickersSet

Telegram/SourceFiles/chat_helpers/tabbed_selector.cpp

@@ -938,7 +938,7 @@ void TabbedSelector::Inner::panelHideFinished() {
 }
 
 TabbedSelector::InnerFooter::InnerFooter(QWidget *parent)
-: TWidget(parent) {
+: RpWidget(parent) {
 	resize(st::emojiPanWidth, st::emojiFooterHeight);
 }
 

Telegram/SourceFiles/chat_helpers/tabbed_selector.h

@@ -276,7 +276,7 @@ private:
 
 };
 
-class TabbedSelector::InnerFooter : public TWidget {
+class TabbedSelector::InnerFooter : public Ui::RpWidget {
 public:
 	InnerFooter(QWidget *parent);
 

Telegram/SourceFiles/data/data_cloud_file.cpp

@@ -26,7 +26,7 @@ void CloudImageView::set(
 		not_null<Main::Session*> session,
 		QImage image) {
 	_image.emplace(std::move(image));
-	session->downloaderTaskFinished().notify();
+	session->notifyDownloaderTaskFinished();
 }
 
 CloudImage::CloudImage() = default;

Telegram/SourceFiles/data/data_cloud_themes.cpp

@@ -222,8 +222,7 @@ void CloudThemes::loadDocumentAndInvoke(
 		return;
 	}
 	if (!alreadyWaiting) {
-		base::ObservableViewer(
-			_session->downloaderTaskFinished()
+		_session->downloaderTaskFinished(
 		) | rpl::filter([=, &value] {
 			return value.documentMedia->loaded();
 		}) | rpl::start_with_next([=, &value] {

Telegram/SourceFiles/data/data_document_media.cpp

@@ -168,7 +168,7 @@ void DocumentMedia::setGoodThumbnail(QImage thumbnail) {
 		return;
 	}
 	_goodThumbnail = std::make_unique<Image>(std::move(thumbnail));
-	_owner->session().downloaderTaskFinished().notify();
+	_owner->session().notifyDownloaderTaskFinished();
 }
 
 Image *DocumentMedia::thumbnailInline() const {
@@ -206,7 +206,7 @@ QSize DocumentMedia::thumbnailSize() const {
 
 void DocumentMedia::setThumbnail(QImage thumbnail) {
 	_thumbnail = std::make_unique<Image>(std::move(thumbnail));
-	_owner->session().downloaderTaskFinished().notify();
+	_owner->session().notifyDownloaderTaskFinished();
 }
 
 QByteArray DocumentMedia::videoThumbnailContent() const {

Telegram/SourceFiles/data/data_photo_media.cpp

@@ -82,7 +82,7 @@ void PhotoMedia::set(PhotoSize size, QImage image) {
 			Qt::SmoothTransformation);
 	}
 	_images[index] = std::make_unique<Image>(std::move(image));
-	_owner->session().downloaderTaskFinished().notify();
+	_owner->session().notifyDownloaderTaskFinished();
 }
 
 bool PhotoMedia::loaded() const {

Telegram/SourceFiles/data/stickers/data_stickers_set.cpp

@@ -34,7 +34,7 @@ void StickersSetThumbnailView::set(
 	} else {
 		_image = std::make_unique<Image>(std::move(image));
 	}
-	session->downloaderTaskFinished().notify();
+	session->notifyDownloaderTaskFinished();
 }
 
 Image *StickersSetThumbnailView::image() const {

Telegram/SourceFiles/dialogs/dialogs_inner_widget.cpp

@@ -132,7 +132,10 @@ InnerWidget::InnerWidget(
 	});
 	_cancelSearchFromUser->hide();
 
-	subscribe(session().downloaderTaskFinished(), [=] { update(); });
+	session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
+		update();
+	}, lifetime());
 
 	subscribe(Core::App().notifications().settingsChanged(), [=](
 			Window::Notifications::ChangeType change) {

Telegram/SourceFiles/history/history_widget.cpp

@@ -305,7 +305,11 @@ HistoryWidget::HistoryWidget(
 , _topShadow(this) {
 	setAcceptDrops(true);
 
-	subscribe(session().downloaderTaskFinished(), [=] { update(); });
+	session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
+		update();
+	}, lifetime());
+
 	connect(_scroll, SIGNAL(scrolled()), this, SLOT(onScroll()));
 	_historyDown->addClickHandler([=] { historyDownClicked(); });
 	_unreadMentions->addClickHandler([=] { showNextUnreadMention(); });

Telegram/SourceFiles/info/media/info_media_list_widget.cpp

@@ -585,21 +585,27 @@ void ListWidget::start() {
 			invalidatePaletteCache();
 		}
 	}, lifetime());
-	ObservableViewer(
-		session().downloaderTaskFinished()
-	) | rpl::start_with_next([this] { update(); }, lifetime());
+
+	session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
+		update();
+	}, lifetime());
+
 	session().data().itemLayoutChanged(
 	) | rpl::start_with_next([this](auto item) {
 		itemLayoutChanged(item);
 	}, lifetime());
+
 	session().data().itemRemoved(
 	) | rpl::start_with_next([this](auto item) {
 		itemRemoved(item);
 	}, lifetime());
+
 	session().data().itemRepaintRequest(
 	) | rpl::start_with_next([this](auto item) {
 		repaintItem(item);
 	}, lifetime());
+
 	_controller->mediaSourceQueryValue(
 	) | rpl::start_with_next([this]{
 		restart();

Telegram/SourceFiles/inline_bots/inline_results_widget.cpp

@@ -58,9 +58,11 @@ Inner::Inner(
 	setMouseTracking(true);
 	setAttribute(Qt::WA_OpaquePaintEvent);
 
-	subscribe(_controller->session().downloaderTaskFinished(), [this] {
+	_controller->session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
 		update();
-	});
+	}, lifetime());
+
 	subscribe(controller->gifPauseLevelChanged(), [this] {
 		if (!_controller->isGifPausedAtLeastFor(Window::GifPauseReason::InlineResults)) {
 			update();

Telegram/SourceFiles/main/main_session.cpp

@@ -181,7 +181,11 @@ Storage::Domain &Session::domainLocal() const {
 	return _account->domainLocal();
 }
 
-base::Observable<void> &Session::downloaderTaskFinished() {
+void Session::notifyDownloaderTaskFinished() {
+	downloader().notifyTaskFinished();
+}
+
+rpl::producer<> Session::downloaderTaskFinished() const {
 	return downloader().taskFinished();
 }
 

Telegram/SourceFiles/main/main_session.h

@@ -121,7 +121,8 @@ public:
 		-> const base::flat_set<not_null<Window::SessionController*>> &;
 
 	// Shortcuts.
-	[[nodiscard]] base::Observable<void> &downloaderTaskFinished();
+	void notifyDownloaderTaskFinished();
+	[[nodiscard]] rpl::producer<> downloaderTaskFinished() const;
 	[[nodiscard]] MTP::DcId mainDcId() const;
 	[[nodiscard]] MTP::Instance &mtp() const;
 	[[nodiscard]] const MTP::ConfigFields &serverConfig() const;

Telegram/SourceFiles/media/view/media_view_overlay_widget.cpp

@@ -3530,8 +3530,7 @@ void OverlayWidget::setSession(not_null<Main::Session*> session) {
 	_session = session;
 	setWindowIcon(Window::CreateIcon(session));
 
-	base::ObservableViewer(
-		session->downloaderTaskFinished()
+	session->downloaderTaskFinished(
 	) | rpl::start_with_next([=] {
 		if (!isHidden()) {
 			updateControls();

Telegram/SourceFiles/platform/mac/mac_touchbar.mm

@@ -812,8 +812,7 @@ void AppendEmojiPacks(
 		[self setNeedsDisplayInRect:PeerRectByIndex(userpicIndex)];
 	};
 	const auto listenToDownloaderFinished = [=] {
-		base::ObservableViewer(
-			_session->downloaderTaskFinished()
+		_session->downloaderTaskFinished(
 		) | rpl::start_with_next([=] {
 			const auto all = ranges::all_of(_pins, [=](const auto &pin) {
 				return (!pin->peer->hasUserpic())
@@ -1193,8 +1192,7 @@ void AppendEmojiPacks(
 		[self updateImage];
 		return;
 	}
-	base::ObservableViewer(
-		document->session().downloaderTaskFinished()
+	document->session().downloaderTaskFinished(
 	) | rpl::start_with_next([=] {
 		_image = _media->getStickerSmall();
 		if (_image) {

Telegram/SourceFiles/profile/profile_block_peer_list.cpp

@@ -33,7 +33,11 @@ PeerListWidget::PeerListWidget(
 , _removeText(removeText)
 , _removeWidth(st::normalFont->width(_removeText)) {
 	setMouseTracking(true);
-	subscribe(peer->session().downloaderTaskFinished(), [=] { update(); });
+
+	peer->session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
+		update();
+	}, lifetime());
 }
 
 int PeerListWidget::resizeGetHeight(int newWidth) {

Telegram/SourceFiles/storage/download_manager_mtproto.h

@@ -38,8 +38,11 @@ public:
 	void enqueue(not_null<Task*> task, int priority);
 	void remove(not_null<Task*> task);
 
-	[[nodiscard]] base::Observable<void> &taskFinished() {
-		return _taskFinishedObservable;
+	void notifyTaskFinished() {
+		_taskFinished.fire({});
+	}
+	[[nodiscard]] rpl::producer<> taskFinished() const {
+		return _taskFinished.events();
 	}
 
 	int changeRequestedAmount(MTP::DcId dcId, int index, int delta);
@@ -101,7 +104,7 @@ private:
 
 	const not_null<ApiWrap*> _api;
 
-	base::Observable<void> _taskFinishedObservable;
+	rpl::event_stream<> _taskFinished;
 
 	base::flat_map<MTP::DcId, DcBalanceData> _balanceData;
 	base::Timer _resetGenerationTimer;

Telegram/SourceFiles/storage/file_download.cpp

@@ -140,7 +140,7 @@ void FileLoader::finishWithBytes(const QByteArray &data) {
 		Platform::File::PostprocessDownloaded(
 			QFileInfo(_file).absoluteFilePath());
 	}
-	_session->downloaderTaskFinished().notify();
+	_session->notifyDownloaderTaskFinished();
 	_updates.fire_done();
 }
 
@@ -440,7 +440,7 @@ bool FileLoader::finalizeResult() {
 					_cacheTag));
 		}
 	}
-	_session->downloaderTaskFinished().notify();
+	_session->notifyDownloaderTaskFinished();
 	_updates.fire_done();
 	return true;
 }

Telegram/SourceFiles/ui/special_buttons.cpp

@@ -639,8 +639,7 @@ void UserpicButton::setupPeerViewers() {
 		update();
 	}, lifetime());
 
-	base::ObservableViewer(
-		_peer->session().downloaderTaskFinished()
+	_peer->session().downloaderTaskFinished(
 	) | rpl::filter([=] {
 		return _waiting;
 	}) | rpl::start_with_next([=] {

Telegram/SourceFiles/window/notifications_manager_default.cpp

@@ -21,6 +21,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "window/themes/window_theme.h"
 #include "storage/file_download.h"
 #include "main/main_session.h"
+#include "main/main_account.h"
 #include "history/history.h"
 #include "history/history_item.h"
 #include "platform/platform_specific.h"
@@ -229,14 +230,16 @@ void Manager::showNextFromQueue() {
 void Manager::subscribeToSession(not_null<Main::Session*> session) {
 	auto i = _subscriptions.find(session);
 	if (i == _subscriptions.end()) {
-		i = _subscriptions.emplace(session, base::Subscription()).first;
-		session->lifetime().add([=] {
+		i = _subscriptions.emplace(session).first;
+		session->account().sessionChanges(
+		) | rpl::start_with_next([=] {
 			_subscriptions.remove(session);
-		});
-	} else if (i->second) {
+		}, i->second.lifetime);
+	} else if (i->second.subscription) {
 		return;
 	}
-	i->second = session->downloaderTaskFinished().add_subscription([=] {
+	session->downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
 		auto found = false;
 		for (const auto &notification : _notifications) {
 			if (const auto history = notification->maybeHistory()) {
@@ -247,9 +250,9 @@ void Manager::subscribeToSession(not_null<Main::Session*> session) {
 			}
 		}
 		if (!found) {
-			_subscriptions[session].destroy();
+			_subscriptions[session].subscription.destroy();
 		}
-	});
+	}, i->second.subscription);
 }
 
 void Manager::moveWidgets() {

Telegram/SourceFiles/window/notifications_manager_default.h

@@ -56,6 +56,10 @@ private:
 	friend class internal::Widget;
 	using Notification = internal::Notification;
 	using HideAllButton = internal::HideAllButton;
+	struct SessionSubscription {
+		rpl::lifetime subscription;
+		rpl::lifetime lifetime;
+	};
 
 	[[nodiscard]] QPixmap hiddenUserpicPlaceholder() const;
 
@@ -91,7 +95,7 @@ private:
 	std::vector<std::unique_ptr<Notification>> _notifications;
 	base::flat_map<
 		not_null<Main::Session*>,
-		base::Subscription> _subscriptions;
+		SessionSubscription> _subscriptions;
 
 	std::unique_ptr<HideAllButton> _hideAll;
 

Telegram/SourceFiles/window/themes/window_themes_cloud_list.cpp

@@ -666,8 +666,7 @@ void CloudList::subscribeToDownloadFinished() {
 	if (_downloadFinishedLifetime) {
 		return;
 	}
-	base::ObservableViewer(
-		_window->session().downloaderTaskFinished()
+	_window->session().downloaderTaskFinished(
 	) | rpl::start_with_next([=] {
 		auto &&waiting = _elements | ranges::view::filter(&Element::waiting);
 		const auto still = ranges::count_if(waiting, [&](Element &element) {

Telegram/SourceFiles/window/window_main_menu.cpp

@@ -580,7 +580,10 @@ MainMenu::MainMenu(
 	_version->setLink(1, std::make_shared<UrlClickHandler>(qsl("https://desktop.telegram.org/changelog")));
 	_version->setLink(2, std::make_shared<LambdaClickHandler>([] { Ui::show(Box<AboutBox>()); }));
 
-	subscribe(_controller->session().downloaderTaskFinished(), [=] { update(); });
+	_controller->session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
+		update();
+	}, lifetime());
 
 	_controller->session().changes().peerUpdates(
 		_controller->session().user(),

Telegram/SourceFiles/window/window_media_preview.cpp

@@ -36,9 +36,10 @@ MediaPreviewWidget::MediaPreviewWidget(
 , _controller(controller)
 , _emojiSize(Ui::Emoji::GetSizeLarge() / cIntRetinaFactor()) {
 	setAttribute(Qt::WA_TransparentForMouseEvents);
-	subscribe(_controller->session().downloaderTaskFinished(), [=] {
+	_controller->session().downloaderTaskFinished(
+	) | rpl::start_with_next([=] {
 		update();
-	});
+	}, lifetime());
 }
 
 QRect MediaPreviewWidget::updateArea() const {