Add test that repros observer cache invalidation

Author: SanderMertens

test/core/project.json

@@ -964,7 +964,8 @@
                 "defer_remove_set_parent_different_stages_w_observer",
                 "defer_reparent_to_deleted_parent",
                 "delete_mixed_tree_1",
-                "delete_mixed_tree_2"
+                "delete_mixed_tree_2",
+                "delete_mixed_tree_3"
             ]
         }, {
             "id": "Hierarchies",

test/core/src/NonFragmentingChildOf.c

@@ -5770,3 +5770,24 @@ void NonFragmentingChildOf_delete_mixed_tree_2(void) {
 
     ecs_fini(world);
 }
+
+void NonFragmentingChildOf_delete_mixed_tree_3(void) {
+    ecs_world_t *world = ecs_init(); // using ecs_init vs. ecs_mini causes a crash
+
+    ecs_entity_t root = ecs_new(world);
+    ecs_entity_t prefab = ecs_new_w_id(world, EcsPrefab);
+
+    ecs_entity_t parent = ecs_new(world);
+    ecs_set(world, parent, EcsParent, {root});
+    ecs_add_pair(world, parent, EcsIsA, prefab);
+
+    ecs_entity_t child_a = ecs_new(world);
+    ecs_add_pair(world, child_a, EcsChildOf, parent);
+    
+    ecs_entity_t child_b = ecs_new(world);
+    ecs_set(world, child_b, EcsParent, {parent});
+
+    ecs_delete(world, root);
+
+    ecs_fini(world);
+}

test/core/src/main.c

@@ -933,6 +933,7 @@ void NonFragmentingChildOf_defer_remove_set_parent_different_stages_w_observer(v
 void NonFragmentingChildOf_defer_reparent_to_deleted_parent(void);
 void NonFragmentingChildOf_delete_mixed_tree_1(void);
 void NonFragmentingChildOf_delete_mixed_tree_2(void);
+void NonFragmentingChildOf_delete_mixed_tree_3(void);
 
 // Testsuite 'Hierarchies'
 void Hierarchies_setup(void);
@@ -6823,6 +6824,10 @@ bake_test_case NonFragmentingChildOf_testcases[] = {
     {
         "delete_mixed_tree_2",
         NonFragmentingChildOf_delete_mixed_tree_2
+    },
+    {
+        "delete_mixed_tree_3",
+        NonFragmentingChildOf_delete_mixed_tree_3
     }
 };
 
@@ -15735,7 +15740,7 @@ static bake_test_suite suites[] = {
         "NonFragmentingChildOf",
         NULL,
         NULL,
-        227,
+        228,
         NonFragmentingChildOf_testcases
     },
     {