Fix issue with yield_existing observers and not terms

Summary: This diff fixes an issue where a yield_existing observers with a first term that has a not operator would fail to yield existing entities.

Differential Revision: D64272384

distr/flecs.c

@@ -14567,8 +14567,6 @@ void flecs_multi_observer_invoke(
 
         ecs_table_unlock(it->world, table);
         flecs_stage_set_system(world->stages[0], old_system);
-
-        return;
     } else {
         /* While the observer query was strictly speaking evaluated, it's more
          * useful to measure how often the observer was actually invoked. */
@@ -14579,6 +14577,40 @@ void flecs_multi_observer_invoke(
     return;
 }
 
+static
+void flecs_multi_observer_invoke_no_query(
+    ecs_iter_t *it) 
+{
+    ecs_observer_t *o = it->ctx;
+    flecs_poly_assert(o, ecs_observer_t);
+
+    ecs_world_t *world = it->real_world;
+    ecs_table_t *table = it->table;
+    ecs_iter_t user_it = *it;
+
+    user_it.ctx = o->ctx;
+    user_it.callback_ctx = o->callback_ctx;
+    user_it.run_ctx = o->run_ctx;
+    user_it.param = it->param;
+    user_it.callback = o->callback;
+    user_it.system = o->entity;
+    user_it.event = it->event;
+
+    ecs_entity_t old_system = flecs_stage_set_system(
+        world->stages[0], o->entity);
+    ecs_table_lock(it->world, table);
+
+    if (o->run) {
+        user_it.next = flecs_default_next_callback;
+        o->run(&user_it);
+    } else {
+        user_it.callback(&user_it);
+    }
+
+    ecs_table_unlock(it->world, table);
+    flecs_stage_set_system(world->stages[0], old_system);
+}
+
 /* For convenience, so applications can (in theory) use a single run callback 
  * that uses ecs_iter_next to iterate results */
 bool flecs_default_next_callback(ecs_iter_t *it) {
@@ -14620,7 +14652,7 @@ void flecs_observer_yield_existing(
 {
     ecs_run_action_t run = o->run;
     if (!run) {
-        run = flecs_multi_observer_invoke;
+        run = flecs_multi_observer_invoke_no_query;
     }
 
     ecs_run_aperiodic(world, EcsAperiodicEmptyTables);

src/observer.c

@@ -551,8 +551,6 @@ void flecs_multi_observer_invoke(
 
         ecs_table_unlock(it->world, table);
         flecs_stage_set_system(world->stages[0], old_system);
-
-        return;
     } else {
         /* While the observer query was strictly speaking evaluated, it's more
          * useful to measure how often the observer was actually invoked. */
@@ -563,6 +561,40 @@ void flecs_multi_observer_invoke(
     return;
 }
 
+static
+void flecs_multi_observer_invoke_no_query(
+    ecs_iter_t *it) 
+{
+    ecs_observer_t *o = it->ctx;
+    flecs_poly_assert(o, ecs_observer_t);
+
+    ecs_world_t *world = it->real_world;
+    ecs_table_t *table = it->table;
+    ecs_iter_t user_it = *it;
+
+    user_it.ctx = o->ctx;
+    user_it.callback_ctx = o->callback_ctx;
+    user_it.run_ctx = o->run_ctx;
+    user_it.param = it->param;
+    user_it.callback = o->callback;
+    user_it.system = o->entity;
+    user_it.event = it->event;
+
+    ecs_entity_t old_system = flecs_stage_set_system(
+        world->stages[0], o->entity);
+    ecs_table_lock(it->world, table);
+
+    if (o->run) {
+        user_it.next = flecs_default_next_callback;
+        o->run(&user_it);
+    } else {
+        user_it.callback(&user_it);
+    }
+
+    ecs_table_unlock(it->world, table);
+    flecs_stage_set_system(world->stages[0], old_system);
+}
+
 /* For convenience, so applications can (in theory) use a single run callback 
  * that uses ecs_iter_next to iterate results */
 bool flecs_default_next_callback(ecs_iter_t *it) {
@@ -604,7 +636,7 @@ void flecs_observer_yield_existing(
 {
     ecs_run_action_t run = o->run;
     if (!run) {
-        run = flecs_multi_observer_invoke;
+        run = flecs_multi_observer_invoke_no_query;
     }
 
     ecs_run_aperiodic(world, EcsAperiodicEmptyTables);

test/core/project.json

@@ -487,7 +487,7 @@
                 "emplace_inherited",
                 "override_component",
                 "delete_w_override_component",
-                "delete_w_override_on_remove_isa", 
+                "delete_w_override_on_remove_isa",
                 "ctor_after_emplace",
                 "ctor_dtor_after_remove",
                 "ctor_dtor_after_clear",
@@ -1537,6 +1537,7 @@
                 "yield_existing_flags_w_multi_observer",
                 "yield_on_create_without_on_add",
                 "yield_on_delete_without_on_remove",
+                "yield_existing_w_not_first_term",
                 "observer_superset_wildcard",
                 "observer_superset_wildcard_add_isa",
                 "observer_superset_wildcard_add_isa_at_offset",

test/core/src/Observer.c

@@ -4479,6 +4479,47 @@ void Observer_yield_on_delete_without_on_remove(void) {
     ecs_fini(world);
 }
 
+void Observer_yield_existing_w_not_first_term(void) {
+    ecs_world_t *world = ecs_mini();
+
+    ECS_TAG(world, Foo);
+    ECS_TAG(world, Bar);
+
+    /* Create entities before trigger */
+    ecs_entity_t e1 = ecs_new_w(world, Foo);
+    ecs_entity_t e2 = ecs_new_w(world, Foo);
+    ecs_entity_t e3 = ecs_new_w(world, Foo);
+
+    test_assert(e1 != 0);
+    test_assert(e2 != 0);
+    test_assert(e3 != 0);
+
+    ecs_add(world, e3, Bar);
+
+    Probe ctx = {0};
+    ecs_entity_t t = ecs_observer_init(world, &(ecs_observer_desc_t){
+        .query.terms = {{ Bar, .oper = EcsNot }, { Foo }},
+        .events = {EcsOnAdd},
+        .callback = Observer,
+        .ctx = &ctx,
+        .yield_existing = true
+    });
+
+    test_int(ctx.invoked, 1);
+    test_int(ctx.count, 2);
+    test_int(ctx.system, t);
+    test_int(ctx.event, EcsOnAdd);
+    test_int(ctx.term_count, 2);
+    test_null(ctx.param);
+
+    test_int(ctx.e[0], e1);
+    test_int(ctx.e[1], e2);
+    test_int(ctx.c[0][0], Bar);
+    test_int(ctx.c[0][1], Foo);
+
+    ecs_fini(world);
+}
+
 void Observer_observer_superset_wildcard(void) {
     ecs_world_t *world = ecs_mini();
 

test/core/src/main.c

@@ -1476,6 +1476,7 @@ void Observer_on_add_remove_no_on_remove_yield_existing(void);
 void Observer_yield_existing_flags_w_multi_observer(void);
 void Observer_yield_on_create_without_on_add(void);
 void Observer_yield_on_delete_without_on_remove(void);
+void Observer_yield_existing_w_not_first_term(void);
 void Observer_observer_superset_wildcard(void);
 void Observer_observer_superset_wildcard_add_isa(void);
 void Observer_observer_superset_wildcard_add_isa_at_offset(void);
@@ -7970,6 +7971,10 @@ bake_test_case Observer_testcases[] = {
         "yield_on_delete_without_on_remove",
         Observer_yield_on_delete_without_on_remove
     },
+    {
+        "yield_existing_w_not_first_term",
+        Observer_yield_existing_w_not_first_term
+    },
     {
         "observer_superset_wildcard",
         Observer_observer_superset_wildcard
@@ -11225,7 +11230,7 @@ static bake_test_suite suites[] = {
         "Observer",
         NULL,
         NULL,
-        222,
+        223,
         Observer_testcases
     },
     {