fix: release pooled EmoteReferences on the legacy-emote early-out (#9665)

Playing a legacy emote while legacy animations were disabled took an early
return before returning the rented EmoteReferences to the pool, leaking them.
Add the instance to emotesInUse before the early-out.

Verified on real Unity 6000.4.0f1 (compile + EditMode/PlayMode regression tests).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0154z8arJX8jRXX8vipKGSj2

Author: 2 people

Explorer/Assets/DCL/AvatarRendering/Emotes/Systems/Play/EmotePlayer.cs

@@ -58,6 +58,8 @@ public bool Play(GameObject mainAsset, AudioClip? audioAsset, bool isLooping, bo
             EmoteReferences? emoteReferences = AcquireEmoteReferences(mainAsset, audioAsset, isLooping, isSpatial, in view, emoteInUse);
             if (emoteReferences == null) return false;
 
+            emotesInUse.Add(emoteReferences, pools[mainAsset]);
+
             if (emoteReferences.legacy)
             {
                 if (!legacyAnimationsEnabled)
@@ -71,7 +73,6 @@ public bool Play(GameObject mainAsset, AudioClip? audioAsset, bool isLooping, bo
             else
                 PlayMecanimEmote(view, ref emoteComponent, emoteReferences, isLooping);
 
-            emotesInUse.Add(emoteReferences, pools[mainAsset]);
             emoteComponent.CurrentEmoteReference = emoteReferences;
             return true;
         }
@@ -87,6 +88,8 @@ public bool PlayMasked(GameObject mainAsset, AudioClip? audioAsset, bool isLoopi
             EmoteReferences? emoteReferences = AcquireEmoteReferences(mainAsset, audioAsset, isLooping, isSpatial, in view, emoteInUse);
             if (emoteReferences == null) return false;
 
+            emotesInUse.Add(emoteReferences, pools[mainAsset]);
+
             if (emoteReferences.legacy)
             {
                 if (!PlayMaskedLegacyEmote(view, ref maskedEmote, emoteReferences, isLooping))
@@ -98,7 +101,6 @@ public bool PlayMasked(GameObject mainAsset, AudioClip? audioAsset, bool isLoopi
             else
                 PlayMaskedMecanimEmote(view, ref maskedEmote, emoteReferences, isLooping);
 
-            emotesInUse.Add(emoteReferences, pools[mainAsset]);
             maskedEmote.CurrentEmoteReference = emoteReferences;
             return true;
         }

Explorer/Assets/DCL/AvatarRendering/Emotes/Tests/EmotePlayerShould.cs

@@ -0,0 +1,69 @@
+using DCL.AvatarRendering.AvatarShape.UnityInterface;
+using DCL.AvatarRendering.Emotes.Play;
+using NSubstitute;
+using NUnit.Framework;
+using UnityEngine;
+using Object = UnityEngine.Object;
+
+namespace DCL.AvatarRendering.Emotes.Tests
+{
+    public class EmotePlayerShould
+    {
+        private GameObject poolRoot = null!;
+        private GameObject audioSourcePrefab = null!;
+        private GameObject legacyEmoteAsset = null!;
+        private GameObject avatarGameObject = null!;
+        private EmotePlayer emotePlayer = null!;
+        private IAvatarView avatarView = null!;
+
+        [SetUp]
+        public void Setup()
+        {
+            poolRoot = new GameObject("ROOT_POOL_CONTAINER");
+            audioSourcePrefab = new GameObject("EmoteAudioSource");
+            audioSourcePrefab.AddComponent<AudioSource>();
+
+            emotePlayer = new EmotePlayer(audioSourcePrefab.GetComponent<AudioSource>(),
+                ScriptableObject.CreateInstance<EmoteMaskCatalog>(), legacyAnimationsEnabled: false);
+
+            // Legacy emote asset: an Animator with no controller (so CreateNewEmoteReference takes the
+            // legacy branch) plus an Animation carrying a legacy clip.
+            legacyEmoteAsset = new GameObject("LegacyEmoteAsset");
+            legacyEmoteAsset.AddComponent<Animator>();
+            var animation = legacyEmoteAsset.AddComponent<Animation>();
+            var clip = new AnimationClip { legacy = true, name = "wave" };
+            animation.AddClip(clip, clip.name);
+
+            avatarGameObject = new GameObject("Avatar");
+
+            avatarView = Substitute.For<IAvatarView>();
+            avatarView.GetTransform().Returns(avatarGameObject.transform);
+        }
+
+        [TearDown]
+        public void TearDown()
+        {
+            Object.DestroyImmediate(avatarGameObject);
+            Object.DestroyImmediate(legacyEmoteAsset);
+            Object.DestroyImmediate(audioSourcePrefab);
+            Object.DestroyImmediate(poolRoot);
+        }
+
+        // Regression for https://github.com/decentraland/unity-explorer/issues/9665: a legacy emote
+        // rejected because legacyAnimationsEnabled is false must return its pooled instance to the pool.
+        // Before the fix the reference was registered in emotesInUse only after the early-out, so Stop()
+        // released nothing and the instance stayed parented under the avatar, leaking on every play.
+        [Test]
+        public void NotLeakPooledInstanceWhenLegacyEmoteRejected()
+        {
+            var emoteComponent = new CharacterEmoteComponent();
+
+            bool played = emotePlayer.Play(legacyEmoteAsset, null, false, false, in avatarView, ref emoteComponent);
+
+            Assert.IsFalse(played);
+            Assert.IsNull(emoteComponent.CurrentEmoteReference);
+            Assert.IsNull(avatarGameObject.GetComponentInChildren<EmoteReferences>(true),
+                "Rejected legacy emote leaked a pooled instance under the avatar.");
+        }
+    }
+}