fix issue with really large tile tables

Author: caldwellc

lib/geoPackage.ts

@@ -301,7 +301,7 @@ export class GeoPackage {
       const tm = tileMatrixDao.createObject(result);
       // verify first that there are actual tiles at this zoom level due to QGIS doing weird things and
       // creating tile matrix entries for zoom levels that have no tiles
-      if (tileMatrixDao.tileCount(tm)) {
+      if (tileMatrixDao.hasTiles(tm)) {
         tileMatrices.push(tm);
       }
     });

lib/tiles/matrix/tileMatrixDao.ts

@@ -73,4 +73,10 @@ export class TileMatrixDao extends Dao<TileMatrix> {
     const result = this.connection.get(query, whereArgs);
     return result?.count;
   }
+  hasTiles(tileMatrix: TileMatrix): boolean {
+    const where = this.buildWhereWithFieldAndValue(TileColumn.COLUMN_ZOOM_LEVEL, tileMatrix.zoom_level);
+    const whereArgs = this.buildWhereArgs([tileMatrix.zoom_level]);
+    const query = SqliteQueryBuilder.buildQuery(false, tileMatrix.table_name, undefined, where);
+    return this.connection.get(query, whereArgs) != null;
+  }
 }