Only preallocate the memory when usin moveto/lineto

src/map/mapsforge/mapdata.cpp

@@ -497,6 +497,9 @@ int MapData::level(int zoom) const
 
 void MapData::points(const RectC &rect, int zoom, QList<Point> *list)
 {
+	if (!rect.isValid())
+		return;
+
 	int l(level(zoom));
 	PointCTX ctx(this, rect, zoom, list);
 	double min[2], max[2];
@@ -528,6 +531,9 @@ void MapData::points(const VectorTile *tile, const RectC &rect, int zoom,
 
 void MapData::paths(const RectC &rect, int zoom, QList<Path> *list)
 {
+	if (!rect.isValid())
+		return;
+
 	int l(level(zoom));
 	PathCTX ctx(this, rect, zoom, list);
 	double min[2], max[2];

src/map/mapsforge/rastertile.cpp

@@ -200,17 +200,17 @@ QPainterPath RasterTile::painterPath(const Polygon &polygon, bool curve) const
 {
 	QPainterPath path;
 
+	if (curve) {
 #if QT_VERSION >= QT_VERSION_CHECK(5, 13, 0)
-	int size = 0;
-	for (int i = 0; i < polygon.size(); i++)
-		size += polygon.at(i).size();
-	path.reserve(size);
+		int size = 0;
+		for (int i = 0; i < polygon.size(); i++)
+			size += polygon.at(i).size();
+		path.reserve(size);
 #endif // QT 5.13
 
-	for (int i = 0; i < polygon.size(); i++) {
-		const QVector<Coordinates> &subpath = polygon.at(i);
+		for (int i = 0; i < polygon.size(); i++) {
+			const QVector<Coordinates> &subpath = polygon.at(i);
 
-		if (curve) {
 			QPointF p1(ll2xy(subpath.first()));
 			QPointF p2(0, 0);
 			QPointF p3(0, 0);
@@ -223,7 +223,11 @@ QPainterPath RasterTile::painterPath(const Polygon &polygon, bool curve) const
 				p1 = p3;
 			}
 			path.quadTo(p2, p3);
-		} else {
+		}
+	} else {
+		for (int i = 0; i < polygon.size(); i++) {
+			const QVector<Coordinates> &subpath = polygon.at(i);
+
 			QVector<QPointF> p(subpath.size());
 			for (int j = 0; j < subpath.size(); j++)
 				p[j] = ll2xy(subpath.at(j));

src/map/mapsforgemap.cpp

@@ -211,9 +211,10 @@ void MapsforgeMap::draw(QPainter *painter, const QRectF &rect, Flags flags)
 				_data.points(pointRectD.toRectC(_projection, 20), _zoom,
 				  &points);
 
-				tiles.append(RasterTile(_projection, _transform, &_style, _zoom,
-				  QRect(ttl, QSize(_data.tileSize(), _data.tileSize())),
-				  _tileRatio, paths, points));
+				if (paths.size() || points.size())
+					tiles.append(RasterTile(_projection, _transform, &_style,
+					  _zoom, QRect(ttl, QSize(_data.tileSize(), _data.tileSize())),
+					  _tileRatio, paths, points));
 			}
 		}
 	}