Fix issue where deleting mixed trees would not set EcsIdMarkedForDelete flag

Author: SanderMertens

distr/flecs.c

@@ -18130,6 +18130,8 @@ void flecs_component_delete_non_fragmenting_childof(
     ecs_world_t *world,
     ecs_component_record_t *cr)
 {
+    cr->flags |= EcsIdMarkedForDelete;
+
     ecs_pair_record_t *pr = cr->pair;
     int32_t i, count = ecs_vec_count(&pr->ordered_children);
     ecs_entity_t *children = ecs_vec_first(&pr->ordered_children);

src/on_delete.c

@@ -204,6 +204,8 @@ void flecs_component_delete_non_fragmenting_childof(
     ecs_world_t *world,
     ecs_component_record_t *cr)
 {
+    cr->flags |= EcsIdMarkedForDelete;
+
     ecs_pair_record_t *pr = cr->pair;
     int32_t i, count = ecs_vec_count(&pr->ordered_children);
     ecs_entity_t *children = ecs_vec_first(&pr->ordered_children);

test/core/src/NonFragmentingChildOf.c

@@ -5772,9 +5772,18 @@ void NonFragmentingChildOf_delete_mixed_tree_2(void) {
 }
 
 void NonFragmentingChildOf_delete_mixed_tree_3(void) {
-    ecs_world_t *world = ecs_init(); // using ecs_init vs. ecs_mini causes a crash
+    ecs_world_t *world = ecs_mini();
+
+    ECS_TAG(world, Foo);
+
+    ecs_observer(world, {
+        .query.terms = {{ Foo, .src.id = EcsUp }},
+        .events = { EcsOnRemove },
+        .callback = DummyObserver
+    });
 
     ecs_entity_t root = ecs_new(world);
+    ecs_add(world, root, Foo);
     ecs_entity_t prefab = ecs_new_w_id(world, EcsPrefab);
 
     ecs_entity_t parent = ecs_new(world);
@@ -5789,5 +5798,10 @@ void NonFragmentingChildOf_delete_mixed_tree_3(void) {
 
     ecs_delete(world, root);
 
+    test_assert(!ecs_is_alive(world, root));
+    test_assert(!ecs_is_alive(world, parent));
+    test_assert(!ecs_is_alive(world, child_a));
+    test_assert(!ecs_is_alive(world, child_b));
+
     ecs_fini(world);
 }