Fix issue with deleting & recycling same id in command buffer

flecs.c

@@ -8101,7 +8101,7 @@ bool flecs_defer_end(
             for (i = 0; i < count; i ++) {
                 ecs_cmd_t *cmd = &cmds[i];
                 ecs_entity_t e = cmd->entity;
-                bool is_alive = flecs_entities_is_valid(world, e);
+                bool is_alive = flecs_entities_is_alive(world, e);
 
                 /* A negative index indicates the first command for an entity */
                 if (merge_to_world && (cmd->next_for_entity < 0)) {

src/entity.c

@@ -4729,7 +4729,7 @@ bool flecs_defer_end(
             for (i = 0; i < count; i ++) {
                 ecs_cmd_t *cmd = &cmds[i];
                 ecs_entity_t e = cmd->entity;
-                bool is_alive = flecs_entities_is_valid(world, e);
+                bool is_alive = flecs_entities_is_alive(world, e);
 
                 /* A negative index indicates the first command for an entity */
                 if (merge_to_world && (cmd->next_for_entity < 0)) {

test/api/project.json

@@ -2545,7 +2545,8 @@
                 "on_set_hook_before_on_add_for_existing_component",
                 "defer_2_sets_w_observer_same_component",
                 "defer_2_sets_w_observer_other_component",
-                "on_remove_after_deferred_clear_and_add"
+                "on_remove_after_deferred_clear_and_add",
+                "defer_delete_recycle_same_id"
             ]
         }, {
             "id": "SingleThreadStaging",

test/api/src/DeferredActions.c

@@ -3407,3 +3407,42 @@ void DeferredActions_on_remove_after_deferred_clear_and_add(void) {
 
     ecs_fini(world);
 }
+
+static void Recycle(ecs_iter_t *it) {
+    ecs_new_id(it->world);
+    *(ecs_entity_t*)it->ctx = ecs_new_id(it->world);
+}
+
+void DeferredActions_defer_delete_recycle_same_id(void) {
+    ecs_world_t *world = ecs_mini();
+
+    ECS_TAG(world, Foo);
+    ECS_TAG(world, Bar);
+
+    ecs_entity_t parent = ecs_new_id(world);
+    ecs_entity_t e1 = ecs_new_w_pair(world, EcsChildOf, parent);
+    ecs_entity_t e2 = ecs_new_id(world);
+
+    ecs_observer(world, {
+        .filter.terms = {
+            { .id = ecs_id(Foo) }
+        },
+        .events = { EcsOnAdd },
+        .callback = Recycle,
+        .ctx = &e1
+    });
+
+    ecs_defer_begin(world);
+    ecs_delete(world, parent);
+    ecs_add(world, e2, Foo);
+    ecs_add(world, e1, Bar);
+    ecs_defer_end(world);
+
+    test_assert(!ecs_is_alive(world, parent));
+    test_assert(ecs_is_alive(world, e2));
+    test_assert(ecs_is_alive(world, e1));
+    test_assert((uint32_t)e1 != e1);
+    test_assert(ecs_has(world, e2, Foo));
+
+    ecs_fini(world);
+}

test/api/src/main.c

@@ -2455,6 +2455,7 @@ void DeferredActions_on_set_hook_before_on_add_for_existing_component(void);
 void DeferredActions_defer_2_sets_w_observer_same_component(void);
 void DeferredActions_defer_2_sets_w_observer_other_component(void);
 void DeferredActions_on_remove_after_deferred_clear_and_add(void);
+void DeferredActions_defer_delete_recycle_same_id(void);
 
 // Testsuite 'SingleThreadStaging'
 void SingleThreadStaging_setup(void);
@@ -12144,6 +12145,10 @@ bake_test_case DeferredActions_testcases[] = {
     {
         "on_remove_after_deferred_clear_and_add",
         DeferredActions_on_remove_after_deferred_clear_and_add
+    },
+    {
+        "defer_delete_recycle_same_id",
+        DeferredActions_defer_delete_recycle_same_id
     }
 };
 
@@ -13054,7 +13059,7 @@ static bake_test_suite suites[] = {
         "DeferredActions",
         NULL,
         NULL,
-        115,
+        116,
         DeferredActions_testcases
     },
     {