🐛 Fix problem with thumbnail generation

frontend/src/app/render_wasm/api.cljs

@@ -1031,8 +1031,9 @@
      (perf/end-measure "set-objects")
      (process-pending shapes thumbnails full noop-fn
                       (fn []
-                        (when render-callback (render-callback))
-                        (render-finish)
+                        (if render-callback
+                          (render-callback)
+                          (render-finish))
                         (ug/dispatch! (ug/event "penpot:wasm:set-objects")))))))
 
 (defn clear-focus-mode
@@ -1360,9 +1361,8 @@
         all-children
         (->> ids
              (mapcat #(cfh/get-children-with-self objects %)))]
-
     (h/call wasm/internal-module "_init_shapes_pool" (count all-children))
-    (run! set-object all-children)
+    (run! (partial set-object objects) all-children)
 
     (let [content (-> (calculate-bool* bool-type ids)
                       (path.impl/path-data))]

frontend/src/app/worker/thumbnails.cljs

@@ -179,6 +179,7 @@
 
                       (->> (render-canvas-blob canvas width height bgcolor)
                            (p/fnly (fn [data cause]
+                                     (wasm.api/clear-canvas)
                                      (if cause
                                        (rx/error! subs cause)
                                        (rx/push! subs