From adb249c39484671d6448597a4898fb463e71e072 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois?= <mockersf@gmail.com>
Date: Mon, 28 Dec 2020 22:25:01 +0100
Subject: [PATCH] enable change detection for labels (#1155)

---
 crates/bevy_core/src/label.rs | 3 +--
 crates/bevy_core/src/lib.rs   | 5 +++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/crates/bevy_core/src/label.rs b/crates/bevy_core/src/label.rs
index 179841c53178a..93f7f8ec8e533 100644
--- a/crates/bevy_core/src/label.rs
+++ b/crates/bevy_core/src/label.rs
@@ -74,8 +74,7 @@ impl EntityLabels {
 
 pub(crate) fn entity_labels_system(
     mut entity_labels: ResMut<EntityLabels>,
-    // the system runs in an early stage and so can't use a Changed<Labels> filter
-    query: Query<(Entity, &Labels)>,
+    query: Query<(Entity, &Labels), Changed<Labels>>,
 ) {
     let entity_labels = entity_labels.deref_mut();
 
diff --git a/crates/bevy_core/src/lib.rs b/crates/bevy_core/src/lib.rs
index 03ed4dba4d78a..1058554cbf542 100644
--- a/crates/bevy_core/src/lib.rs
+++ b/crates/bevy_core/src/lib.rs
@@ -18,7 +18,7 @@ pub mod prelude {
     pub use crate::{DefaultTaskPoolOptions, EntityLabels, Labels, Time, Timer};
 }
 
-use bevy_app::prelude::*;
+use bevy_app::{prelude::*, startup_stage};
 
 /// Adds core functionality to Apps.
 #[derive(Default)]
@@ -40,6 +40,7 @@ impl Plugin for CorePlugin {
             .register_type::<Range<f32>>()
             .register_type::<Timer>()
             .add_system_to_stage(stage::FIRST, time_system.system())
-            .add_system_to_stage(stage::PRE_UPDATE, entity_labels_system.system());
+            .add_startup_system_to_stage(startup_stage::POST_STARTUP, entity_labels_system.system())
+            .add_system_to_stage(stage::POST_UPDATE, entity_labels_system.system());
     }
 }