Fix new window crash for unavailable channels.

Telegram/SourceFiles/dialogs/dialogs_widget.cpp

@@ -263,7 +263,7 @@ Widget::Widget(
 			const auto showAtMsgId = controller->uniqueChatsInSearchResults()
 				? ShowAtUnreadMsgId
 				: row.message.fullId.msg;
-			if (row.newWindow) {
+			if (row.newWindow && controller->canShowSeparateWindow(peer)) {
 				const auto active = controller->activeChatCurrent();
 				if (const auto history = active.history()) {
 					if (history->peer == peer) {

Telegram/SourceFiles/history/history_widget.cpp

@@ -737,8 +737,10 @@ HistoryWidget::HistoryWidget(
 		if (flags & PeerUpdateFlag::UnavailableReason) {
 			const auto unavailable = _peer->computeUnavailableReason();
 			if (!unavailable.isEmpty()) {
-				controller->showBackFromStack();
+				closeCurrent();
-				controller->show(Ui::MakeInformBox(unavailable));
+				if (const auto primary = Core::App().primaryWindow()) {
+					primary->show(Ui::MakeInformBox(unavailable));
+				}
 				return;
 			}
 		}
@@ -2932,7 +2934,7 @@ void HistoryWidget::unreadCountUpdated() {
 	if (_history->chatListUnreadMark()) {
 		crl::on_main(this, [=, history = _history] {
 			if (history == _history) {
-				controller()->showBackFromStack();
+				closeCurrent();
 				_cancelRequests.fire({});
 			}
 		});
@@ -2942,6 +2944,14 @@ void HistoryWidget::unreadCountUpdated() {
 	}
 }
 
+void HistoryWidget::closeCurrent() {
+	if (controller()->isPrimary()) {
+		controller()->showBackFromStack();
+	} else {
+		controller()->window().close();
+	}
+}
+
 void HistoryWidget::messagesFailed(const MTP::Error &error, int requestId) {
 	if (error.type() == qstr("CHANNEL_PRIVATE")
 		&& _peer->isChannel()
@@ -2951,13 +2961,15 @@ void HistoryWidget::messagesFailed(const MTP::Error &error, int requestId) {
 		|| error.type() == qstr("CHANNEL_PUBLIC_GROUP_NA")
 		|| error.type() == qstr("USER_BANNED_IN_CHANNEL")) {
 		auto was = _peer;
-		controller()->showBackFromStack();
+		closeCurrent();
-		Ui::ShowMultilineToast({
+		if (const auto primary = Core::App().primaryWindow()) {
-			.parentOverride = Window::Show(controller()).toastParent(),
+			Ui::ShowMultilineToast({
-			.text = { (was && was->isMegagroup())
+				.parentOverride = Window::Show(primary).toastParent(),
-				? tr::lng_group_not_accessible(tr::now)
+				.text = { (was && was->isMegagroup())
-				: tr::lng_channel_not_accessible(tr::now) },
+					? tr::lng_group_not_accessible(tr::now)
-		});
+					: tr::lng_channel_not_accessible(tr::now) },
+			});
+		}
 		return;
 	}
 
@@ -2972,7 +2984,7 @@ void HistoryWidget::messagesFailed(const MTP::Error &error, int requestId) {
 		_preloadDownRequest = 0;
 	} else if (_firstLoadRequest == requestId) {
 		_firstLoadRequest = 0;
-		controller()->showBackFromStack();
+		closeCurrent();
 	} else if (_delayedShowAtRequest == requestId) {
 		_delayedShowAtRequest = 0;
 	}

Telegram/SourceFiles/history/history_widget.h

@@ -390,6 +390,7 @@ private:
 	void handleHistoryChange(not_null<const History*> history);
 	void showAboutTopPromotion();
 	void unreadCountUpdated();
+	void closeCurrent();
 
 	[[nodiscard]] int computeMaxFieldHeight() const;
 	void toggleMuteUnmute();

Telegram/SourceFiles/mainwidget.cpp

@@ -1314,6 +1314,7 @@ void MainWidget::ui_showPeerHistory(
 		}
 		const auto unavailable = peer->computeUnavailableReason();
 		if (!unavailable.isEmpty()) {
+			Assert(isPrimary());
 			if (params.activation != anim::activation::background) {
 				controller()->show(Ui::MakeInformBox(unavailable));
 			}

Telegram/SourceFiles/window/window_session_controller.cpp

@@ -1220,6 +1220,11 @@ void SessionController::closeThirdSection() {
 	}
 }
 
+bool SessionController::canShowSeparateWindow(
+		not_null<PeerData*> peer) const {
+	return peer->computeUnavailableReason().isEmpty();
+}
+
 void SessionController::showPeer(not_null<PeerData*> peer, MsgId msgId) {
 	const auto currentPeer = activeChatCurrent().peer();
 	if (peer && peer->isChannel() && currentPeer != peer) {

Telegram/SourceFiles/window/window_session_controller.h

@@ -380,6 +380,7 @@ public:
 	void resizeForThirdSection();
 	void closeThirdSection();
 
+	[[nodiscard]] bool canShowSeparateWindow(not_null<PeerData*> peer) const;
 	void showPeer(not_null<PeerData*> peer, MsgId msgId = ShowAtUnreadMsgId);
 
 	void startOrJoinGroupCall(