Code cleanup

Although technically not needed here, it workarounds the issue with the broken
Qt SVG imageformat plugin (QTBUG-119910).

src/map/mbtilesmap.cpp

@@ -129,15 +129,14 @@ bool MBTilesMap::getBounds()
 
 bool MBTilesMap::getTileSize()
 {
-	QString sql("SELECT tile_data FROM tiles LIMIT 1");
+	QString sql("SELECT zoom_level, tile_data FROM tiles LIMIT 1");
 	QSqlQuery query(sql, _db);
 	query.first();
 
-	QByteArray data = query.value(0).toByteArray();
+	QByteArray z(QByteArray::number(query.value(0).toInt()));
+	QByteArray data = query.value(1).toByteArray();
 	QBuffer buffer(&data);
-	/* Explicitly specify the image plugin in case of vector tiles
+	QImageReader reader(&buffer, z);
-	   (QTBUG-119910 workaround) */
-	QImageReader reader(&buffer, _scalable ? QByteArray("mvt") : QByteArray());
 	QSize tileSize(reader.size());
 
 	if (!tileSize.isValid() || tileSize.width() != tileSize.height()) {
@@ -217,9 +216,9 @@ MBTilesMap::MBTilesMap(const QString &fileName, QObject *parent)
 		return;
 	if (!getBounds())
 		return;
-	getTileFormat();
 	if (!getTileSize())
 		return;
+	getTileFormat();
 	getTilePixelRatio();
 	getName();
 

src/map/mbtilesmap.h

@@ -21,10 +21,8 @@ public:
 	const QPixmap &pixmap() const {return _pixmap;}
 
 	void load() {
-		QByteArray z(QString::number(_zoom).toLatin1());
-
 		QBuffer buffer(&_data);
-		QImageReader reader(&buffer, z);
+		QImageReader reader(&buffer, QByteArray::number(_zoom));
 		if (_scaledSize)
 			reader.setScaledSize(QSize(_scaledSize, _scaledSize));
 		_pixmap = QPixmap::fromImage(reader.read());

src/map/tileloader.cpp

@@ -7,6 +7,8 @@
 #include "tileloader.h"
 
 #define SUBSTITUTE_CHAR '$'
+#define IS_INT(zoom) \
+	((QMetaType::Type)((zoom).type()) == QMetaType::Int)
 
 class TileImage
 {
@@ -18,7 +20,8 @@ public:
 	void load()
 	{
 		QImage img;
-		QByteArray z(_tile->zoom().toString().toLatin1());
+		QByteArray z(IS_INT(_tile->zoom())
+		  ? QByteArray::number(_tile->zoom().toInt()) : QByteArray());
 		QImageReader reader(_file, z);
 		if (_scaledSize)
 			reader.setScaledSize(QSize(_scaledSize, _scaledSize));
@@ -220,7 +223,7 @@ QUrl TileLoader::tileUrl(const FetchTile &tile) const
 
 QString TileLoader::tileFile(const FetchTile &tile) const
 {
-	QString zoom(((QMetaType::Type)(tile.zoom().type()) == QMetaType::Int)
+	QString zoom(IS_INT(tile.zoom())
 	  ? tile.zoom().toString() : fsSafeStr(tile.zoom().toString()));
 
 	return _dir + QLatin1Char('/') + zoom + QLatin1Char('-')