Make Source::getZoomRange return an optional range

2 files changed, 6 insertions, 4 deletions

diff --git a/src/mbgl/style/sources/geojson_source_impl.cpp b/src/mbgl/style/sources/geojson_source_impl.cpp
index 5ceb4f71e0..b050e5482e 100644
--- a/src/mbgl/style/sources/geojson_source_impl.cpp
+++ b/src/mbgl/style/sources/geojson_source_impl.cpp
@@ -153,9 +153,11 @@ void GeoJSONSource::Impl::loadDescription(FileSource& fileSource) {
     });
 }
 
-Range<uint8_t> GeoJSONSource::Impl::getZoomRange() const {
-    assert(loaded);
-    return { 0, options.maxzoom };
+optional<Range<uint8_t>> GeoJSONSource::Impl::getZoomRange() const {
+    if (loaded) {
+        return { { 0, options.maxzoom }};
+    }
+    return {};
 }
 
 std::unique_ptr<Tile> GeoJSONSource::Impl::createTile(const OverscaledTileID& tileID,
diff --git a/src/mbgl/style/sources/geojson_source_impl.hpp b/src/mbgl/style/sources/geojson_source_impl.hpp
index 05302d6bc0..b827a0b26c 100644
--- a/src/mbgl/style/sources/geojson_source_impl.hpp
+++ b/src/mbgl/style/sources/geojson_source_impl.hpp
@@ -28,7 +28,7 @@ public:
         return util::tileSize;
     }
 
-    Range<uint8_t> getZoomRange() const final;
+    optional<Range<uint8_t>> getZoomRange() const final;
 
 private:
     void _setGeoJSON(const GeoJSON&);