From 0f20cfaa570872d14c24cee679363e0b5ff2ce47 Mon Sep 17 00:00:00 2001
From: Ricky Taylor <rickytaylor26@gmail.com>
Date: Mon, 2 Oct 2023 01:05:36 +0100
Subject: [PATCH] Only attempt to copy resources that still exist from scenes
 (#9984)

# Objective

Avert a panic when removing resources from Scenes.

### Reproduction Steps
```rust
let mut scene = Scene::new(World::default());
scene.world.init_resource::<Time>();
scene.world.remove_resource::<Time>();
scene.clone_with(&app.resource::<AppTypeRegistry>());
```

### Panic Message
```
thread 'Compute Task Pool (10)' panicked at 'Requested resource bevy_time::time::Time does not exist in the `World`.
                Did you forget to add it using `app.insert_resource` / `app.init_resource`?
                Resources are also implicitly added via `app.add_event`,
                and can be added by plugins.', .../bevy/crates/bevy_ecs/src/reflect/resource.rs:203:52

```

## Solution

Check that the resource actually still exists before copying.

---

## Changelog

- resolved a panic caused by removing resources from scenes
---
 crates/bevy_scene/src/scene.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/crates/bevy_scene/src/scene.rs b/crates/bevy_scene/src/scene.rs
index db9f7fae7d..afb178eb19 100644
--- a/crates/bevy_scene/src/scene.rs
+++ b/crates/bevy_scene/src/scene.rs
@@ -63,7 +63,11 @@ impl Scene {
         let type_registry = type_registry.read();
 
         // Resources archetype
-        for (component_id, _) in self.world.storages().resources.iter() {
+        for (component_id, resource_data) in self.world.storages().resources.iter() {
+            if !resource_data.is_present() {
+                continue;
+            }
+
             let component_info = self
                 .world
                 .components()