From 35979922df9de488e67dfdf5d8a7c857527cb2a7 Mon Sep 17 00:00:00 2001
From: bilsen <40690317+bilsen@users.noreply.github.com>
Date: Tue, 31 Aug 2021 20:52:21 +0000
Subject: [PATCH] Fix Option<NonSend<T>> and Option<NonSendMut<T>> (#2757)
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# Objective
Fix `Option<NonSend<T>>` to work when T isn't `Send`
Fix `Option<NonSendMut<T>>` to work when T isnt in the world.

## Solution
Simple two row fix, properly initialize T in `OptionNonSendState` and remove `T: Component` bound for `Option<NonSendMut<T>>`
also added a rudimentary test


Co-authored-by: Ïvar Källström <ivar.kallstrom@gmail.com>
---
 crates/bevy_ecs/src/system/mod.rs          | 46 +++++++++++++++++++++-
 crates/bevy_ecs/src/system/system_param.rs |  4 +-
 2 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/crates/bevy_ecs/src/system/mod.rs b/crates/bevy_ecs/src/system/mod.rs
index 8f0172af97a59..d4fd0ad79909c 100644
--- a/crates/bevy_ecs/src/system/mod.rs
+++ b/crates/bevy_ecs/src/system/mod.rs
@@ -27,8 +27,8 @@ mod tests {
         query::{Added, Changed, Or, QueryState, With, Without},
         schedule::{Schedule, Stage, SystemStage},
         system::{
-            ConfigurableSystem, IntoExclusiveSystem, IntoSystem, Local, Query, QuerySet,
-            RemovedComponents, Res, ResMut, System, SystemState,
+            ConfigurableSystem, IntoExclusiveSystem, IntoSystem, Local, NonSend, NonSendMut, Query,
+            QuerySet, RemovedComponents, Res, ResMut, System, SystemState,
         },
         world::{FromWorld, World},
     };
@@ -331,6 +331,48 @@ mod tests {
         assert!(*world.get_resource::<bool>().unwrap());
     }
 
+    #[test]
+    fn non_send_option_system() {
+        let mut world = World::default();
+
+        world.insert_resource(false);
+        struct NotSend1(std::rc::Rc<i32>);
+        struct NotSend2(std::rc::Rc<i32>);
+        world.insert_non_send(NotSend1(std::rc::Rc::new(0)));
+
+        fn sys(
+            op: Option<NonSend<NotSend1>>,
+            mut _op2: Option<NonSendMut<NotSend2>>,
+            mut run: ResMut<bool>,
+        ) {
+            op.expect("NonSend should exist");
+            *run = true;
+        }
+
+        run_system(&mut world, sys);
+        // ensure the system actually ran
+        assert!(*world.get_resource::<bool>().unwrap());
+    }
+
+    #[test]
+    fn non_send_system() {
+        let mut world = World::default();
+
+        world.insert_resource(false);
+        struct NotSend1(std::rc::Rc<i32>);
+        struct NotSend2(std::rc::Rc<i32>);
+
+        world.insert_non_send(NotSend1(std::rc::Rc::new(1)));
+        world.insert_non_send(NotSend2(std::rc::Rc::new(2)));
+
+        fn sys(_op: NonSend<NotSend1>, mut _op2: NonSendMut<NotSend2>, mut run: ResMut<bool>) {
+            *run = true;
+        }
+
+        run_system(&mut world, sys);
+        assert!(*world.get_resource::<bool>().unwrap());
+    }
+
     #[test]
     fn remove_tracking() {
         let mut world = World::new();
diff --git a/crates/bevy_ecs/src/system/system_param.rs b/crates/bevy_ecs/src/system/system_param.rs
index 2e350c05f3eb1..6f3e731ad3f22 100644
--- a/crates/bevy_ecs/src/system/system_param.rs
+++ b/crates/bevy_ecs/src/system/system_param.rs
@@ -820,7 +820,7 @@ impl<'w, 's, T: 'static> SystemParamFetch<'w, 's> for NonSendState<T> {
 /// See: [`NonSend<T>`]
 pub struct OptionNonSendState<T>(NonSendState<T>);
 
-impl<'w, T: Component> SystemParam for Option<NonSend<'w, T>> {
+impl<'w, T: 'static> SystemParam for Option<NonSend<'w, T>> {
     type Fetch = OptionNonSendState<T>;
 }
 
@@ -877,7 +877,7 @@ unsafe impl<T: 'static> SystemParamState for NonSendMutState<T> {
     fn init(world: &mut World, system_meta: &mut SystemMeta, _config: Self::Config) -> Self {
         system_meta.set_non_send();
 
-        let component_id = world.components.get_or_insert_non_send_resource_id::<T>();
+        let component_id = world.initialize_non_send_resource::<T>();
         let combined_access = system_meta.component_access_set.combined_access_mut();
         if combined_access.has_write(component_id) {
             panic!(