Added '-scale' command-line argument for custom scale.

- Fixed #5272.
 - Fixed #5365.
 - Fixed #6055.

Telegram/SourceFiles/core/launcher.cpp

@@ -425,6 +425,7 @@ void Launcher::processArguments() {
 		{ "-sendpath"       , KeyFormat::AllLeftValues },
 		{ "-workdir"        , KeyFormat::OneValue },
 		{ "--"              , KeyFormat::OneValue },
+		{ "-scale"          , KeyFormat::OneValue },
 	};
 	auto parseResult = QMap<QByteArray, QStringList>();
 	auto parsingKey = QByteArray();
@@ -474,6 +475,14 @@ void Launcher::processArguments() {
 		}
 	}
 	gStartUrl = parseResult.value("--", {}).join(QString());
+
+	const auto scaleKey = parseResult.value("-scale", {});
+	if (scaleKey.size() > 0) {
+		const auto value = scaleKey[0].toInt();
+		gConfigScale = ((value < 75) || (value > 300))
+			? kInterfaceScaleAuto
+			: value;
+	}
 }
 
 int Launcher::executeApplication() {

Telegram/SourceFiles/settings/settings_main.cpp

@@ -125,14 +125,24 @@ void SetupInterfaceScale(
 		object_ptr<Ui::SettingsSlider>(container, st::settingsSlider),
 		icon ? st::settingsScalePadding : st::settingsBigScalePadding);
 
-	static const auto ScaleValues = (cIntRetinaFactor() > 1)
-		? std::vector<int>{ 100, 110, 120, 130, 140, 150 }
-		: std::vector<int>{ 100, 125, 150, 200, 250, 300 };
+	static const auto ScaleValues = [&] {
+		auto values = (cIntRetinaFactor() > 1)
+			? std::vector<int>{ 100, 110, 120, 130, 140, 150 }
+			: std::vector<int>{ 100, 125, 150, 200, 250, 300 };
+		if (cConfigScale() == kInterfaceScaleAuto) {
+			return values;
+		}
+		if (ranges::find(values, cConfigScale()) == end(values)) {
+			values.push_back(cConfigScale());
+		}
+		return values;
+	}();
+
 	const auto sectionFromScale = [](int scale) {
 		scale = cEvalScale(scale);
 		auto result = 0;
 		for (const auto value : ScaleValues) {
-			if (scale <= value) {
+			if (scale == value) {
 				break;
 			}
 			++result;

Telegram/SourceFiles/storage/localstorage.cpp

@@ -1521,7 +1521,10 @@ bool _readSetting(quint32 blockId, QDataStream &stream, int version, ReadSetting
 		stream >> v;
 		if (!_checkStreamStatus(stream)) return false;
 
-		SetScaleChecked(v);
+		// If cConfigScale() has value then it was set via command line.
+		if (cConfigScale() == kInterfaceScaleAuto) {
+			SetScaleChecked(v);
+		}
 	} break;
 
 	case dbiLangOld: {