Properly save and restore caches when entering/leaving the walkthrough

modules/services/osm.js

@@ -1,4 +1,5 @@
 import _chunk from 'lodash-es/chunk';
+import _cloneDeep from 'lodash-es/cloneDeep';
 import _extend from 'lodash-es/extend';
 import _forEach from 'lodash-es/forEach';
 import _filter from 'lodash-es/filter';
@@ -893,9 +894,27 @@ export default {
     },
 
 
-    loadedTiles: function(_) {
-        if (!arguments.length) return _tileCache.loaded;
-        _tileCache.loaded = _;
+    caches: function(obj) {
+        if (!arguments.length) {
+            return {
+                tile: _cloneDeep(_tileCache),
+                note: _cloneDeep(_noteCache),
+                user: _cloneDeep(_userCache)
+            };
+        }
+
+        if (obj.tile) {
+            _tileCache = obj.tile;
+            _tileCache.inflight = {};
+        }
+        if (obj.note) {
+            _noteCache = obj.note;
+            _tileCache.inflight = {};
+        }
+        if (obj.user) {
+            _userCache = obj.user;
+        }
+
         return this;
     },
 
@@ -969,18 +988,6 @@ export default {
     },
 
 
-    loadedNotes: function(_) {
-        if (!arguments.length) return _noteCache.loaded;
-        _noteCache.loaded = _;
-        return this;
-    },
-
-
-    notesCache: function() {
-        return _noteCache;
-    },
-
-
     toggleNoteStatus: function(note, comment, callback) {
         if (!(note instanceof osmNote) && !(this.getNote(note.id))) return;
         if (!this.authenticated()) return;

modules/ui/intro/intro.js

@@ -71,7 +71,7 @@ export function uiIntro(context) {
         var background = context.background().baseLayerSource();
         var overlays = context.background().overlayLayerSources();
         var opacity = d3_selectAll('#map .layer-background').style('opacity');
-        var loadedTiles = osm && osm.loadedTiles();
+        var caches = osm && osm.caches();
         var baseEntities = context.history().graph().base().entities;
         var countryCode = services.geocoder.countryCode;
 
@@ -147,7 +147,7 @@ export function uiIntro(context) {
             curtain.remove();
             navwrap.remove();
             d3_selectAll('#map .layer-background').style('opacity', opacity);
-            if (osm) { osm.toggle(true).reset().loadedTiles(loadedTiles); }
+            if (osm) { osm.toggle(true).reset().caches(caches); }
             context.history().reset().merge(_values(baseEntities));
             context.background().baseLayerSource(background);
             overlays.forEach(function (d) { context.background().toggleOverlayLayer(d); });