1 files changed, 34 insertions, 5 deletions
diff --git a/src/mbgl/map/source.cpp b/src/mbgl/map/source.cpp
index ed57ddce0b..4432b3a490 100644
--- a/src/mbgl/map/source.cpp
+++ b/src/mbgl/map/source.cpp
@@ -90,14 +90,13 @@ void Source::load() {
     // URL may either be a TileJSON file, or a GeoJSON file.
     FileSource* fs = util::ThreadContext::getFileSource();
     req = fs->request({ Resource::Kind::Source, url }, [this](Response res) {
-        if (res.stale) {
-            // Only handle fresh responses.
+        if (res.error) {
+            observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error(res.error->message)));
             return;
         }
-        req = nullptr;
 
-        if (res.error) {
-            observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error(res.error->message)));
+        if (res.notModified) {
+            // We got the same data back as last time. Abort early.
             return;
         }
 
@@ -111,6 +110,7 @@ void Source::load() {
             return;
         }
 
+        bool reloadTiles = false;
         if (type == SourceType::Vector || type == SourceType::Raster) {
             // Create a new copy of the SourceInfo object that holds the base values we've parsed
             // from the stylesheet. Then merge in the values parsed from the TileJSON we retrieved
@@ -124,10 +124,39 @@ void Source::load() {
                 std::transform(newInfo->tiles.begin(), newInfo->tiles.end(), newInfo->tiles.begin(),
                                util::mapbox::normalizeRasterTileURL);
             }
+
+            // Check whether previous information specifies different tile
+            if (info && info->tiles != newInfo->tiles) {
+                reloadTiles = true;
+
+                // Tile size changed: We need to recalculate the tiles we need to load because we
+                // might have to load tiles for a different zoom level
+                // This is done automatically when we trigger the onSourceLoaded observer below.
+
+                // Min/Max zoom changed: We need to recalculate what tiles to load, if we have tiles
+                // loaded that are outside the new zoom range
+                // This is done automatically when we trigger the onSourceLoaded observer below.
+
+                // Attribution changed: We need to notify the embedding application that this
+                // changed. See https://github.com/mapbox/mapbox-gl-native/issues/2723
+                // This is not yet implemented.
+
+                // Center/bounds changed: We're not using these values currently
+            }
+
             info = std::move(newInfo);
         } else if (type == SourceType::GeoJSON) {
             info = std::make_unique<SourceInfo>();
             geojsonvt = StyleParser::parseGeoJSON(d);
+            reloadTiles = true;
+        }
+
+        if (reloadTiles) {
+            // Tile information changed because we got new GeoJSON data, or a new tile URL.
+            tilePtrs.clear();
+            tileDataMap.clear();
+            tiles.clear();
+            cache.clear();
         }
 
         loaded = true;