Allow raster source tile updates to re-trigger tile request that failed previously

src/source/raster_tile_source.ts

@@ -85,7 +85,7 @@ export class RasterTileSource extends Evented implements Source {
         extend(this, pick(options, ['url', 'scheme', 'tileSize']));
     }
 
-    async load() {
+    async load(sourceDataChanged: boolean = false) {
         this._loaded = false;
         this.fire(new Event('dataloading', {dataType: 'source'}));
         this._tileJSONRequest = new AbortController();
@@ -101,7 +101,7 @@ export class RasterTileSource extends Evented implements Source {
                 // before the TileJSON arrives. this makes sure the tiles needed are loaded once TileJSON arrives
                 // ref: https://github.com/mapbox/mapbox-gl-js/pull/4347#discussion_r104418088
                 this.fire(new Event('data', {dataType: 'source', sourceDataType: 'metadata'}));
-                this.fire(new Event('data', {dataType: 'source', sourceDataType: 'content'}));
+                this.fire(new Event('data', {dataType: 'source', sourceDataType: 'content', sourceDataChanged}));
             }
         } catch (err) {
             this._tileJSONRequest = null;
@@ -133,7 +133,9 @@ export class RasterTileSource extends Evented implements Source {
 
         callback();
 
-        this.load();
+        const sourceDataChanged = true;
+
+        this.load(sourceDataChanged);
     }
 
     /**

src/source/source_cache.test.ts

@@ -528,10 +528,37 @@
         sourceCache.onAdd(undefined);
         // we expect the source cache to have five tiles, but only to have reloaded one
         expect(Object.keys(sourceCache._tiles)).toHaveLength(5);
         expect(reloadTileSpy).toHaveBeenCalledTimes(1);
 
     });
 
+    test('does reload errored tiles, if event is source data change', () => {
+        const transform = new Transform();
+        transform.resize(511, 511);
+        transform.zoom = 1;
+
+        const sourceCache = createSourceCache();
+        sourceCache._source.loadTile = async (tile) => {
+            // this transform will try to load the four tiles at z1 and a single z0 tile
+            // we only expect _reloadTile to be called with the 'loaded' z0 tile
+            tile.state = tile.tileID.canonical.z === 1 ? 'errored' : 'loaded';
+        };
+
+        const reloadTileSpy = jest.spyOn(sourceCache, '_reloadTile');
+        sourceCache.on('data', (e) => {
+            if (e.dataType === 'source' && e.sourceDataType === 'metadata') {
+                sourceCache.update(transform);
+                sourceCache.getSource().fire(new Event('data', {dataType: 'source', sourceDataType: 'content', sourceDataChanged: true}));
+            }
+        });
+        sourceCache.onAdd(undefined);
+        // We expect the source cache to have five tiles, and for all of them
+        // to be reloaded
+        expect(Object.keys(sourceCache._tiles)).toHaveLength(5);
+        expect(reloadTileSpy).toHaveBeenCalledTimes(5);
+
+    });
+
 });
 
 describe('SourceCache#update', () => {

src/source/source_cache.ts

@@ -85,7 +85,7 @@
 
         this.on('data', (e: MapSourceDataEvent) => this._dataHandler(e));
 
-        this.on('dataloading', () => {
+        this.on('dataloading', (e) => {
             this._sourceErrored = false;
         });
 
@@ -94,7 +94,7 @@
             this._sourceErrored = this._source.loaded();
         });
 
         this._source = createSource(id, options, dispatcher, this);
 
         this._tiles = {};
         this._cache = new TileCache(0, (tile) => this._unloadTile(tile));
@@ -244,7 +244,7 @@
             !this._coveredTiles[id] && (symbolLayer || !this._tiles[id].holdingForFade());
     }
 
-    reload() {
+    reload(sourceDataChanged?: boolean) {
         if (this._paused) {
             this._shouldReloadOnResume = true;
             return;
@@ -253,7 +253,9 @@
         this._cache.reset();
 
         for (const i in this._tiles) {
-            if (this._tiles[i].state !== 'errored') this._reloadTile(i, 'reloading');
+            if (sourceDataChanged || this._tiles[i].state !== 'errored') {
+                this._reloadTile(i, 'reloading');
+            }
         }
     }
 
@@ -919,7 +921,8 @@
         // for sources with mutable data, this event fires when the underlying data
         // to a source is changed. (i.e. GeoJSONSource#setData and ImageSource#serCoordinates)
         if (this._sourceLoaded && !this._paused && e.dataType === 'source' && eventSourceDataType === 'content') {
-            this.reload();
+            const sourceDataChanged = Boolean(e.sourceDataChanged);
+            this.reload(sourceDataChanged);
             if (this.transform) {
                 this.update(this.transform, this.terrain);
             }

src/ui/events.ts

@@ -450,6 +450,7 @@ export type MapSourceDataEvent = MapLibreEvent & {
     source: SourceSpecification;
     sourceId: string;
     sourceDataType: MapSourceDataType;
+    sourceDataChanged?: boolean;
     /**
      * The tile being loaded or changed, if the event has a `dataType` of `source` and
      * the event is related to loading of a tile.