Allow worker_tile to parse the tile for a fractional zoom level even …

…if it is hidden at the current zoom.

src/source/worker_tile.js

@@ -11,6 +11,7 @@ import type TileCoord from './tile_coord';
 import type SymbolBucket from '../data/bucket/symbol_bucket';
 import type {Actor} from '../util/actor';
 import type StyleLayerIndex from '../style/style_layer_index';
+import type StyleLayer from '../style/style_layer';
 import type {
     WorkerTileParameters,
     WorkerTileCallback,
@@ -93,8 +94,8 @@ class WorkerTile {
                 const layer = family[0];
 
                 assert(layer.source === this.source);
-
-                if (layer.minzoom && this.zoom < layer.minzoom) continue;
+                const layerMinzoom = layer.minzoom;
+                if (layerMinzoom && Math.ceil(this.zoom) < layerMinzoom) continue;
                 if (layer.maxzoom && this.zoom >= layer.maxzoom) continue;
                 if (layer.layout && layer.layout.visibility === 'none') continue;