Made discussion group open in same non-primary window as its channel.

Telegram/SourceFiles/info/profile/info_profile_top_bar.cpp

@@ -922,9 +922,10 @@ void TopBar::setupActions(not_null<Window::SessionController*> controller) {
 					tr::lng_channel_invite_private(tr::now));
 				return;
 			}
-			controller->showPeerHistory(
-				chat,
+			auto params = Window::SectionShow(
 				Window::SectionShow::Way::Forward);
+			params.preferCurrentWindow = true;
+			controller->showPeerHistory(chat, params);
 		});
 		discuss->setAccessibleName(tr::lng_profile_action_short_discuss(tr::now));
 		_actions->add(discuss);

Telegram/SourceFiles/mainwidget.cpp

@@ -1354,6 +1354,8 @@ bool MainWidget::showHistoryInDifferentWindow(
 		return true;
 	} else if (windowId().hasChatsList()) {
 		return false;
+	} else if (params.preferCurrentWindow) {
+		return false;
 	}
 	const auto account = not_null(&session().account());
 	auto primary = Core::App().separateWindowFor(account);

Telegram/SourceFiles/window/window_session_controller.h

@@ -211,6 +211,7 @@ struct SectionShow {
 	bool childColumn = false;
 	bool forbidLayer = false;
 	bool forceTopicsList = false;
+	bool preferCurrentWindow = false;
 	bool reapplyLocalDraft = false;
 	bool dropSameFromStack = false;
 	bool allowDuplicateInStack = false;