From 63d3558b146d7a70278c674b9a8217a1f7c9714a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20T=C5=AFma?= <tumic@cbox.cz>
Date: Sun, 10 Dec 2023 08:46:26 +0100
Subject: [PATCH] Provide the zoom level to QImageReader when fetching the tile
 size

Although technically not needed here, it workarounds the issue with the broken
Qt SVG imageformat plugin (QTBUG-119910).
---
 src/map/mbtilesmap.cpp | 11 +++++------
 src/map/mbtilesmap.h   |  4 +---
 2 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/src/map/mbtilesmap.cpp b/src/map/mbtilesmap.cpp
index 7ac6791a..05c5d67c 100644
--- a/src/map/mbtilesmap.cpp
+++ b/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
-	   (QTBUG-119910 workaround) */
-	QImageReader reader(&buffer, _scalable ? QByteArray("mvt") : QByteArray());
+	QImageReader reader(&buffer, z);
 	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();
 
diff --git a/src/map/mbtilesmap.h b/src/map/mbtilesmap.h
index 2e316f28..c3e9fbf1 100644
--- a/src/map/mbtilesmap.h
+++ b/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());