From b5893e570d2a68471d2f3d147751dcc33bac32e0 Mon Sep 17 00:00:00 2001
From: JoJoJet <21144246+JoJoJet@users.noreply.github.com>
Date: Tue, 17 Jan 2023 03:29:08 +0000
Subject: [PATCH] Add a missing impl of `ReadOnlySystemParam` for
 `Option<NonSend<>>` (#7245)

# Objective

The trait `ReadOnlySystemParam` is not implemented for `Option<NonSend<>>`, even though it should be.

Follow-up to #7243. This fixes another mistake made in #6919.

## Solution

Add the missing impl.
---
 crates/bevy_ecs/src/system/system_param.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/crates/bevy_ecs/src/system/system_param.rs b/crates/bevy_ecs/src/system/system_param.rs
index 921bba36b2710..9cb7fb3dfc8b2 100644
--- a/crates/bevy_ecs/src/system/system_param.rs
+++ b/crates/bevy_ecs/src/system/system_param.rs
@@ -985,6 +985,9 @@ unsafe impl<'a, T: 'static> SystemParam for NonSend<'a, T> {
     }
 }
 
+// SAFETY: Only reads a single World non-send resource
+unsafe impl<T: 'static> ReadOnlySystemParam for Option<NonSend<'_, T>> {}
+
 // SAFETY: this impl defers to `NonSend`, which initializes and validates the correct world access.
 unsafe impl<T: 'static> SystemParam for Option<NonSend<'_, T>> {
     type State = ComponentId;