#1762 Fix issue where OrderedChildren from prefab wasn't correctly applied to instance

SanderMertens · web-flow · commit 7bc1e14a2010 · 2025-08-20T16:48:22.000-07:00
diff --git a/distr/flecs.c b/distr/flecs.c
@@ -6651,10 +6651,13 @@ static
 void flecs_on_unparent(
     ecs_world_t *world,
     ecs_table_t *table,
+    ecs_table_t *other_table,
     int32_t row,
     int32_t count)
 {
-    flecs_unparent_name_index(world, table, row, count);
+    if (other_table) {
+        flecs_unparent_name_index(world, table, row, count);
+    }
     flecs_ordered_children_unparent(world, table, row, count);
 }
 
@@ -6880,7 +6883,7 @@ void flecs_notify_on_remove(
         }
 
         if (diff_flags & (EcsTableEdgeReparent|EcsTableHasOrderedChildren)) {
-            flecs_on_unparent(world, table, row, count);
+            flecs_on_unparent(world, table, other_table, row, count);
         }
 
         if (diff_flags & EcsTableHasDontFragment) {
@@ -12283,6 +12286,13 @@ void flecs_instantiate(
                 world, base, instance, tr->hdr.table, ctx);
         }
         ecs_os_perf_trace_pop("flecs.instantiate");
+
+        if (cr->flags & EcsIdOrderedChildren) {
+            ecs_component_record_t *icr = flecs_components_get(world, ecs_childof(instance));
+            /* If base has children, instance must now have children */
+            ecs_assert(icr != NULL, ECS_INTERNAL_ERROR, NULL);
+            flecs_ordered_children_populate(world, icr);
+        }
     }
 }
 
diff --git a/src/component_actions.c b/src/component_actions.c
@@ -130,10 +130,13 @@ static
 void flecs_on_unparent(
     ecs_world_t *world,
     ecs_table_t *table,
+    ecs_table_t *other_table,
     int32_t row,
     int32_t count)
 {
-    flecs_unparent_name_index(world, table, row, count);
+    if (other_table) {
+        flecs_unparent_name_index(world, table, row, count);
+    }
     flecs_ordered_children_unparent(world, table, row, count);
 }
 
@@ -359,7 +362,7 @@ void flecs_notify_on_remove(
         }
 
         if (diff_flags & (EcsTableEdgeReparent|EcsTableHasOrderedChildren)) {
-            flecs_on_unparent(world, table, row, count);
+            flecs_on_unparent(world, table, other_table, row, count);
         }
 
         if (diff_flags & EcsTableHasDontFragment) {
diff --git a/src/instantiate.c b/src/instantiate.c
@@ -426,5 +426,12 @@ void flecs_instantiate(
                 world, base, instance, tr->hdr.table, ctx);
         }
         ecs_os_perf_trace_pop("flecs.instantiate");
+
+        if (cr->flags & EcsIdOrderedChildren) {
+            ecs_component_record_t *icr = flecs_components_get(world, ecs_childof(instance));
+            /* If base has children, instance must now have children */
+            ecs_assert(icr != NULL, ECS_INTERNAL_ERROR, NULL);
+            flecs_ordered_children_populate(world, icr);
+        }
     }
 }
diff --git a/test/core/project.json b/test/core/project.json
@@ -790,10 +790,14 @@
                 "change_order_not_null_children_zero_count",
                 "change_order_on_parent_without_ordered_children",
                 "change_order",
+                "ordered_children_w_name",
                 "get_ordered_children_empty",
                 "get_ordered_children_invalid",
                 "get_ordered_children",
-                "get_ordered_children_from_stage"
+                "get_ordered_children_from_stage",
+                "get_ordered_children_from_prefab_instance_no_children",
+                "get_ordered_children_from_prefab_instance_3_children",
+                "get_ordered_children_from_prefab_instance_nested_children"
             ]
         }, {
             "id": "Has",
diff --git a/test/core/src/OrderedChildren.c b/test/core/src/OrderedChildren.c
@@ -1241,3 +1241,95 @@ void OrderedChildren_get_ordered_children_from_stage(void) {
 
     ecs_fini(world);
 }
+
+void OrderedChildren_ordered_children_w_name(void) {
+    ecs_world_t *world = ecs_mini();
+
+    ecs_entity_t e = ecs_new_w_id(world, EcsPrefab);
+    ecs_add_id(world, e, EcsOrderedChildren);
+
+    ecs_entity(world, { .parent = e, .name = "a" });
+    ecs_entity(world, { .parent = e, .name = "b" });
+    ecs_entity(world, { .parent = e, .name = "c" });
+
+    ecs_entities_t children = ecs_get_ordered_children(world, e);
+    test_int(children.count, 3);
+    test_str(ecs_get_name(world, children.ids[0]), "a");
+    test_str(ecs_get_name(world, children.ids[1]), "b");
+    test_str(ecs_get_name(world, children.ids[2]), "c");
+
+    ecs_delete(world, e);
+
+    test_assert(ecs_lookup(world, "a") == 0);
+    test_assert(ecs_lookup(world, "b") == 0);
+    test_assert(ecs_lookup(world, "c") == 0);
+
+    ecs_fini(world);
+}
+
+void OrderedChildren_get_ordered_children_from_prefab_instance_no_children(void) {
+    ecs_world_t *world = ecs_mini();
+
+    ecs_entity_t p = ecs_new_w_id(world, EcsPrefab);
+    ecs_add_id(world, p, EcsOrderedChildren);
+
+    ecs_entity_t i = ecs_new_w_pair(world, EcsIsA, p);
+    test_assert(ecs_has_id(world, i, EcsOrderedChildren));
+
+    ecs_entities_t children = ecs_get_ordered_children(world, i);
+    test_int(children.count, 0);
+
+    ecs_fini(world);
+}
+
+void OrderedChildren_get_ordered_children_from_prefab_instance_3_children(void) {
+    ecs_world_t *world = ecs_mini();
+
+    ecs_entity_t p = ecs_new_w_id(world, EcsPrefab);
+    ecs_add_id(world, p, EcsOrderedChildren);
+
+    ecs_entity(world, { .parent = p, .name = "a" });
+    ecs_entity(world, { .parent = p, .name = "b" });
+    ecs_entity(world, { .parent = p, .name = "c" });
+
+    ecs_entity_t i = ecs_new_w_pair(world, EcsIsA, p);
+    test_assert(ecs_has_id(world, i, EcsOrderedChildren));
+
+    ecs_entities_t children = ecs_get_ordered_children(world, i);
+    test_int(children.count, 3);
+    test_str(ecs_get_name(world, children.ids[0]), "a");
+    test_str(ecs_get_name(world, children.ids[1]), "b");
+    test_str(ecs_get_name(world, children.ids[2]), "c");
+
+    ecs_fini(world);
+}
+
+void OrderedChildren_get_ordered_children_from_prefab_instance_nested_children(void) {
+    ecs_world_t *world = ecs_mini();
+
+    ecs_entity_t p = ecs_new_w_id(world, EcsPrefab);
+    ecs_add_id(world, p, EcsOrderedChildren);
+
+    ecs_entity(world, { .parent = p, .name = "a" });
+    ecs_entity(world, { .parent = p, .name = "b" });
+    ecs_entity_t c = ecs_entity(world, { .parent = p, .name = "c" });
+    ecs_add_id(world, c, EcsOrderedChildren);
+    ecs_entity(world, { .parent = c, .name = "x" });
+    ecs_entity(world, { .parent = c, .name = "y" });
+
+    ecs_entity_t i = ecs_new_w_pair(world, EcsIsA, p);
+    test_assert(ecs_has_id(world, i, EcsOrderedChildren));
+
+    ecs_entities_t children = ecs_get_ordered_children(world, i);
+    test_int(children.count, 3);
+    test_str(ecs_get_name(world, children.ids[0]), "a");
+    test_str(ecs_get_name(world, children.ids[1]), "b");
+    test_str(ecs_get_name(world, children.ids[2]), "c");
+
+    ecs_entities_t grandchildren = ecs_get_ordered_children(world, children.ids[2]);
+    test_int(grandchildren.count, 2);
+    test_str(ecs_get_name(world, grandchildren.ids[0]), "x");
+    test_str(ecs_get_name(world, grandchildren.ids[1]), "y");
+
+    ecs_fini(world);
+}
diff --git a/test/core/src/main.c b/test/core/src/main.c
@@ -756,10 +756,14 @@ void OrderedChildren_change_order_null_children_nonzero_count(void);
 void OrderedChildren_change_order_not_null_children_zero_count(void);
 void OrderedChildren_change_order_on_parent_without_ordered_children(void);
 void OrderedChildren_change_order(void);
+void OrderedChildren_ordered_children_w_name(void);
 void OrderedChildren_get_ordered_children_empty(void);
 void OrderedChildren_get_ordered_children_invalid(void);
 void OrderedChildren_get_ordered_children(void);
 void OrderedChildren_get_ordered_children_from_stage(void);
+void OrderedChildren_get_ordered_children_from_prefab_instance_no_children(void);
+void OrderedChildren_get_ordered_children_from_prefab_instance_3_children(void);
+void OrderedChildren_get_ordered_children_from_prefab_instance_nested_children(void);
 
 // Testsuite 'Has'
 void Has_zero(void);
@@ -5580,6 +5584,10 @@ bake_test_case OrderedChildren_testcases[] = {
         "change_order",
         OrderedChildren_change_order
     },
+    {
+        "ordered_children_w_name",
+        OrderedChildren_ordered_children_w_name
+    },
     {
         "get_ordered_children_empty",
         OrderedChildren_get_ordered_children_empty
@@ -5595,6 +5603,18 @@ bake_test_case OrderedChildren_testcases[] = {
     {
         "get_ordered_children_from_stage",
         OrderedChildren_get_ordered_children_from_stage
+    },
+    {
+        "get_ordered_children_from_prefab_instance_no_children",
+        OrderedChildren_get_ordered_children_from_prefab_instance_no_children
+    },
+    {
+        "get_ordered_children_from_prefab_instance_3_children",
+        OrderedChildren_get_ordered_children_from_prefab_instance_3_children
+    },
+    {
+        "get_ordered_children_from_prefab_instance_nested_children",
+        OrderedChildren_get_ordered_children_from_prefab_instance_nested_children
     }
 };
 
@@ -13112,7 +13132,7 @@ static bake_test_suite suites[] = {
         "OrderedChildren",
         NULL,
         NULL,
-        33,
+        37,
         OrderedChildren_testcases
     },
     {

Original file line number	Diff line number	Diff line change
`@@ -6651,10 +6651,13 @@ static`
`6651`	`6651`	`void flecs_on_unparent(`
`6652`	`6652`	`ecs_world_t *world,`
`6653`	`6653`	`ecs_table_t *table,`
	`6654`	`+ ecs_table_t *other_table,`
`6654`	`6655`	`int32_t row,`
`6655`	`6656`	`int32_t count)`
`6656`	`6657`	`{`
`6657`		`- flecs_unparent_name_index(world, table, row, count);`
	`6658`	`+ if (other_table) {`
	`6659`	`+ flecs_unparent_name_index(world, table, row, count);`
	`6660`	`+ }`
`6658`	`6661`	`flecs_ordered_children_unparent(world, table, row, count);`
`6659`	`6662`	`}`
`6660`	`6663`
`@@ -6880,7 +6883,7 @@ void flecs_notify_on_remove(`
`6880`	`6883`	`}`
`6881`	`6884`
`6882`	`6885`	`if (diff_flags & (EcsTableEdgeReparent\|EcsTableHasOrderedChildren)) {`
`6883`		`- flecs_on_unparent(world, table, row, count);`
	`6886`	`+ flecs_on_unparent(world, table, other_table, row, count);`
`6884`	`6887`	`}`
`6885`	`6888`
`6886`	`6889`	`if (diff_flags & EcsTableHasDontFragment) {`
`@@ -12283,6 +12286,13 @@ void flecs_instantiate(`
`12283`	`12286`	`world, base, instance, tr->hdr.table, ctx);`
`12284`	`12287`	`}`
`12285`	`12288`	`ecs_os_perf_trace_pop("flecs.instantiate");`
	`12289`	`+`
	`12290`	`+ if (cr->flags & EcsIdOrderedChildren) {`
	`12291`	`+ ecs_component_record_t *icr = flecs_components_get(world, ecs_childof(instance));`
	`12292`	`+ /* If base has children, instance must now have children */`
	`12293`	`+ ecs_assert(icr != NULL, ECS_INTERNAL_ERROR, NULL);`
	`12294`	`+ flecs_ordered_children_populate(world, icr);`
	`12295`	`+ }`
`12286`	`12296`	`}`
`12287`	`12297`	`}`
`12288`	`12298`
Original file line number	Diff line number	Diff line change
`@@ -130,10 +130,13 @@ static`
`130`	`130`	`void flecs_on_unparent(`
`131`	`131`	`ecs_world_t *world,`
`132`	`132`	`ecs_table_t *table,`
	`133`	`+ ecs_table_t *other_table,`
`133`	`134`	`int32_t row,`
`134`	`135`	`int32_t count)`
`135`	`136`	`{`
`136`		`- flecs_unparent_name_index(world, table, row, count);`
	`137`	`+ if (other_table) {`
	`138`	`+ flecs_unparent_name_index(world, table, row, count);`
	`139`	`+ }`
`137`	`140`	`flecs_ordered_children_unparent(world, table, row, count);`
`138`	`141`	`}`
`139`	`142`
`@@ -359,7 +362,7 @@ void flecs_notify_on_remove(`
`359`	`362`	`}`
`360`	`363`
`361`	`364`	`if (diff_flags & (EcsTableEdgeReparent\|EcsTableHasOrderedChildren)) {`
`362`		`- flecs_on_unparent(world, table, row, count);`
	`365`	`+ flecs_on_unparent(world, table, other_table, row, count);`
`363`	`366`	`}`
`364`	`367`
`365`	`368`	`if (diff_flags & EcsTableHasDontFragment) {`
Original file line number	Diff line number	Diff line change
`@@ -426,5 +426,12 @@ void flecs_instantiate(`
`426`	`426`	`world, base, instance, tr->hdr.table, ctx);`
`427`	`427`	`}`
`428`	`428`	`ecs_os_perf_trace_pop("flecs.instantiate");`
	`429`	`+`
	`430`	`+ if (cr->flags & EcsIdOrderedChildren) {`
	`431`	`+ ecs_component_record_t *icr = flecs_components_get(world, ecs_childof(instance));`
	`432`	`+ /* If base has children, instance must now have children */`
	`433`	`+ ecs_assert(icr != NULL, ECS_INTERNAL_ERROR, NULL);`
	`434`	`+ flecs_ordered_children_populate(world, icr);`
	`435`	`+ }`
`429`	`436`	`}`
`430`	`437`	`}`