reserved screen area in portrait mode

client/renderSDL/ScreenHandler.cpp

@@ -48,6 +48,8 @@ std::tuple<int, int> ScreenHandler::getSupportedScalingRange() const
 	Point renderResolution = getRenderResolution();
 	double reservedAreaWidth = settings["video"]["reservedWidth"].Float();
 	Point availableResolution = Point(renderResolution.x * (1 - reservedAreaWidth), renderResolution.y);
+	if(renderResolution.x < renderResolution.y) // reserved in portrait mode
+		availableResolution = Point(renderResolution.x, renderResolution.y * (1 - reservedAreaWidth));
 
 	double maximalScalingWidth = 100.0 * availableResolution.x / minResolution.x;
 	double maximalScalingHeight = 100.0 * availableResolution.y / minResolution.y;