Depsgraph: Fix violation of evaluated domain

Evaluation must never go to original objects and query them:
this is a huge violation of the entire idea of separating
state across viewports and render engines.

Allowed this to only happen for active dependency graph, where
we at least know order of dependency graph update and user
input.

source/blender/blenkernel/intern/DerivedMesh.c

@@ -2070,7 +2070,6 @@ static void object_get_datamask(const Depsgraph *depsgraph,
                                 bool *r_need_mapping)
 {
   ViewLayer *view_layer = DEG_get_evaluated_view_layer(depsgraph);
-  Object *actob = view_layer->basact ? DEG_get_original_object(view_layer->basact->object) : NULL;
 
   DEG_get_customdata_mask_for_object(depsgraph, ob, r_mask);
 
@@ -2078,6 +2077,13 @@ static void object_get_datamask(const Depsgraph *depsgraph,
     *r_need_mapping = false;
   }
 
+  /* Must never access original objects when dependency graph is not active: it might be already
+   * freed. */
+  if (DEG_is_active(depsgraph)) {
+    return;
+  }
+
+  Object *actob = view_layer->basact ? DEG_get_original_object(view_layer->basact->object) : NULL;
   if (DEG_get_original_object(ob) == actob) {
     bool editing = BKE_paint_select_face_test(actob);