From 4e15d3d8bbe2f6ef0fbdfbcbfff01aaef4f7a7c9 Mon Sep 17 00:00:00 2001
From: James Liu <contact@jamessliu.com>
Date: Mon, 20 Feb 2023 21:51:21 +0000
Subject: [PATCH] Don't log a trace if EventWriter::send_batch is empty (#7753)

# Objective
Fix #5026.

## Solution
Only make a `trace!` log if the event count changed.

---

## Changelog
Changed: `EventWriter::send_batch` will only log a TRACE level log if the batch is non-empty.
---
 crates/bevy_ecs/src/event.rs | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/crates/bevy_ecs/src/event.rs b/crates/bevy_ecs/src/event.rs
index 74367c93ae..0bf6429175 100644
--- a/crates/bevy_ecs/src/event.rs
+++ b/crates/bevy_ecs/src/event.rs
@@ -640,6 +640,7 @@ impl<E: Event> std::iter::Extend<E> for Events<E> {
     where
         I: IntoIterator<Item = E>,
     {
+        let old_count = self.event_count;
         let mut event_count = self.event_count;
         let events = iter.into_iter().map(|event| {
             let event_id = EventId {
@@ -652,11 +653,14 @@ impl<E: Event> std::iter::Extend<E> for Events<E> {
 
         self.events_b.extend(events);
 
-        trace!(
-            "Events::extend() -> ids: ({}..{})",
-            self.event_count,
-            event_count
-        );
+        if old_count != event_count {
+            trace!(
+                "Events::extend() -> ids: ({}..{})",
+                self.event_count,
+                event_count
+            );
+        }
+
         self.event_count = event_count;
     }
 }