Fix leaving channels and supergroups.

Fixes #5838.

Telegram/SourceFiles/apiwrap.cpp

@@ -2363,21 +2363,6 @@ void ApiWrap::clearHistory(not_null<PeerData*> peer, bool revoke) {
 }
 
 void ApiWrap::deleteConversation(not_null<PeerData*> peer, bool revoke) {
-	if (const auto history = _session->data().historyLoaded(peer->id)) {
-		_session->data().setPinnedDialog(history, false);
-		App::main()->removeDialog(history);
-		history->clear();
-		if (const auto channel = peer->asMegagroup()) {
-			channel->addFlags(MTPDchannel::Flag::f_left);
-			if (const auto from = channel->getMigrateFromChat()) {
-				if (const auto migrated = _session->data().historyLoaded(from)) {
-					migrated->updateChatListExistence();
-				}
-			}
-		} else {
-			history->markFullyLoaded();
-		}
-	}
 	if (const auto chat = peer->asChat()) {
 		request(MTPmessages_DeleteChatUser(
 			chat->inputChat,
@@ -2388,13 +2373,13 @@ void ApiWrap::deleteConversation(not_null<PeerData*> peer, bool revoke) {
 		}).fail([=](const RPCError &error) {
 			deleteHistory(peer, false, revoke);
 		}).send();
-		return;
 	} else if (const auto channel = peer->asChannel()) {
 		channel->ptsWaitingForShortPoll(-1);
 		leaveChannel(channel);
 	} else {
 		deleteHistory(peer, false, revoke);
 	}
+	_session->data().deleteConversationLocally(peer);
 }
 
 void ApiWrap::deleteHistory(not_null<PeerData*> peer, bool justClear, bool revoke) {

Telegram/SourceFiles/data/data_session.cpp

@@ -10,6 +10,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "observer_peer.h"
 #include "auth_session.h"
 #include "apiwrap.h"
+#include "mainwidget.h"
 #include "core/application.h"
 #include "core/crash_reports.h" // for CrashReports::SetAnnotation
 #include "ui/image/image.h"
@@ -717,6 +718,25 @@ History *Session::historyLoaded(const PeerData *peer) {
 	return peer ? historyLoaded(peer->id) : nullptr;
 }
 
+void Session::deleteConversationLocally(not_null<PeerData*> peer) {
+	const auto history = historyLoaded(peer);
+	if (history) {
+		setPinnedDialog(history, false);
+		App::main()->removeDialog(history);
+		history->clear();
+	}
+	if (const auto channel = peer->asMegagroup()) {
+		channel->addFlags(MTPDchannel::Flag::f_left);
+		if (const auto from = channel->getMigrateFromChat()) {
+			if (const auto migrated = historyLoaded(from)) {
+				migrated->updateChatListExistence();
+			}
+		}
+	} else if (history) {
+		history->markFullyLoaded();
+	}
+}
+
 void Session::registerSendAction(
 		not_null<History*> history,
 		not_null<UserData*> user,

Telegram/SourceFiles/data/data_session.h

@@ -125,6 +125,8 @@ public:
 	[[nodiscard]] not_null<History*> history(not_null<const PeerData*> peer);
 	[[nodiscard]] History *historyLoaded(const PeerData *peer);
 
+	void deleteConversationLocally(not_null<PeerData*> peer);
+
 	void registerSendAction(
 		not_null<History*> history,
 		not_null<UserData*> user,