From 02025eff0b25bb8c18103dbafc33a764e1989ad4 Mon Sep 17 00:00:00 2001
From: Mike <mike.hsu@gmail.com>
Date: Thu, 31 Aug 2023 15:52:59 -0700
Subject: [PATCH] Fix anonymous set name stack overflow (#9650)

# Objective

- Fixes #9641
- Anonymous sets are named by their system members. When
`ScheduleBuildSettings::report_sets` is on, systems are named by their
sets. So when getting the anonymous set name this would cause an
infinite recursion.

## Solution
- When getting the anonymous system set name, don't get their system's
names with the sets the systems belong to.

## Other Possible solutions
- An alternate solution might be to skip anonymous sets when getting the
system's name for an anonymous set's name.
---
 crates/bevy_ecs/src/schedule/mod.rs      | 33 ++++++++++++++++++++++++
 crates/bevy_ecs/src/schedule/schedule.rs | 10 +++++--
 2 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/crates/bevy_ecs/src/schedule/mod.rs b/crates/bevy_ecs/src/schedule/mod.rs
index ad5bc617a6a2e..88671df5c3575 100644
--- a/crates/bevy_ecs/src/schedule/mod.rs
+++ b/crates/bevy_ecs/src/schedule/mod.rs
@@ -1045,5 +1045,38 @@ mod tests {
                 assert!(ambiguities.contains(entry));
             }
         }
+
+        // Test that anonymous set names work properly
+        // Related issue https://github.com/bevyengine/bevy/issues/9641
+        #[test]
+        fn anonymous_set_name() {
+            use super::*;
+
+            #[derive(ScheduleLabel, Hash, PartialEq, Eq, Debug, Clone)]
+            struct TestSchedule;
+
+            let mut schedule = Schedule::new(TestSchedule);
+            schedule.add_systems((resmut_system, resmut_system).run_if(|| true));
+
+            let mut world = World::new();
+            schedule.graph_mut().initialize(&mut world);
+            let _ = schedule
+                .graph_mut()
+                .build_schedule(world.components(), &TestSchedule.dyn_clone());
+
+            let ambiguities: Vec<_> = schedule
+                .graph()
+                .conflicts_to_string(schedule.graph().conflicting_systems(), world.components())
+                .collect();
+
+            assert_eq!(
+                ambiguities[0],
+                (
+                    "resmut_system (in set (resmut_system, resmut_system))".to_string(),
+                    "resmut_system (in set (resmut_system, resmut_system))".to_string(),
+                    vec!["bevy_ecs::schedule::tests::system_ambiguity::R"],
+                )
+            );
+        }
     }
 }
diff --git a/crates/bevy_ecs/src/schedule/schedule.rs b/crates/bevy_ecs/src/schedule/schedule.rs
index 8b174abdcc7ff..f012cef7ffd3c 100644
--- a/crates/bevy_ecs/src/schedule/schedule.rs
+++ b/crates/bevy_ecs/src/schedule/schedule.rs
@@ -1257,10 +1257,15 @@ enum ReportCycles {
 // methods for reporting errors
 impl ScheduleGraph {
     fn get_node_name(&self, id: &NodeId) -> String {
+        self.get_node_name_inner(id, self.settings.report_sets)
+    }
+
+    #[inline]
+    fn get_node_name_inner(&self, id: &NodeId, report_sets: bool) -> String {
         let mut name = match id {
             NodeId::System(_) => {
                 let name = self.systems[id.index()].get().unwrap().name().to_string();
-                if self.settings.report_sets {
+                if report_sets {
                     let sets = self.names_of_sets_containing_node(id);
                     if sets.is_empty() {
                         name
@@ -1294,7 +1299,8 @@ impl ScheduleGraph {
             self.hierarchy
                 .graph
                 .edges_directed(*id, Direction::Outgoing)
-                .map(|(_, member_id, _)| self.get_node_name(&member_id))
+                // never get the sets of the members or this will infinite recurse when the report_sets setting is on.
+                .map(|(_, member_id, _)| self.get_node_name_inner(&member_id, false))
                 .reduce(|a, b| format!("{a}, {b}"))
                 .unwrap_or_default()
         )