move re-gen of index to model reload

src/main/mesh.js

@@ -360,8 +360,6 @@ function space_init(data) {
                         for (let m of selection.models()) {
                             m.deleteSelections(mode);
                             space.refresh()
-                            // re-gen face index
-                            api.mode.check();
                         }
                     } else {
                         for (let s of selection.list(true)) {

src/mesh/model.js

@@ -221,6 +221,8 @@ mesh.model = class MeshModel extends mesh.object {
         this.wireframe(was);
         // fixup normals
         this.normals({refresh: true});
+        // re-gen face index in surface mode
+        mesh.api.mode.check();
     }
 
     rename(file) {