fix assertion error

mapbox · Oct 18, 2021 · d0afb1b · d0afb1b
1 parent 8047cd5
commit d0afb1b
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/source/source_cache.js b/src/source/source_cache.js
@@ -595,7 +595,7 @@ class SourceCache extends Evented {
         if (idealTileIDs.length === 0) { return retain; }
 
         const checked: {[_: number | string]: boolean } = {};
-        const minZoom = idealTileIDs[idealTileIDs.length - 1].overscaledZ;
+        const minZoom = idealTileIDs.reduce((min, id) => Math.min(min, id.overscaledZ), Infinity);
         const maxZoom = idealTileIDs[0].overscaledZ;
         assert(minZoom <= maxZoom);
         const minCoveringZoom = Math.max(maxZoom - SourceCache.maxOverzooming, this._source.minzoom);