Don't Panic (#651)

Don't panic when despawning recursively

CHANGELOG.md

@@ -13,11 +13,14 @@
   - This allows drop-in use of colors from most applications.
   - New methods `Color::rgb_linear` and `Color::rgba_linear` will accept colors already in linear sRGB (the old behavior)
   - Individual color-components must now be accessed through setters and getters: `.r`, `.g`, `.b`, `.a`, `.set_r`, `.set_g`, `.set_b`, `.set_a`, and the corresponding methods with the `*_linear` suffix.
-- Despawning an entity multiple times causes a debug-level log message to be emitted instead of a panic [649]
+- Despawning an entity multiple times causes a debug-level log message to be emitted instead of a panic [649] [651]
+
 
 [552]: https://github.com/bevyengine/bevy/pull/552
 [616]: https://github.com/bevyengine/bevy/pull/616
 [649]: https://github.com/bevyengine/bevy/pull/649
+[651]: https://github.com/bevyengine/bevy/pull/651
+
 
 ## Version 0.2.1 (2020-9-20)
 

crates/bevy_transform/src/hierarchy/hierarchy.rs

@@ -67,7 +67,9 @@ fn despawn_with_children_recursive_inner(world: &mut World, entity: Entity) {
         }
     }
 
-    world.despawn(entity).unwrap();
+    if let Err(e) = world.despawn(entity) {
+        log::debug!("Failed to despawn entity {:?}: {}", entity, e);
+    }
 }
 
 impl WorldWriter for DespawnRecursive {
@@ -128,6 +130,7 @@ mod tests {
         let parent_entity = world.get::<Children>(grandparent_entity).unwrap()[0];
 
         command_buffer.despawn_recursive(parent_entity);
+        command_buffer.despawn_recursive(parent_entity); // despawning the same entity twice should not panic
         command_buffer.apply(&mut world, &mut resources);
 
         let results = world