Retry aligning audio playlist with main playlist if levelloaded came …

…too early (#4600)

* Retry align audio playlist with main playlist if levelloaded came too early

Fixes #4288.

* Revert "Retry align audio playlist with main playlist if levelloaded came too early"

This reverts commit b1a2d82.

* Emit AUDIO_TRACK_LOADED event if LEVEL_LOADED came too early

Fixes #4288.

* Mock mainDetails in test

src/controller/audio-stream-controller.ts

@@ -55,6 +55,7 @@ class AudioStreamController
   private waitingData: WaitingForPTSData | null = null;
   private mainDetails: LevelDetails | null = null;
   private bufferFlushed: boolean = false;
+  private cachedTrackLoadedData: TrackLoadedData | null = null;
 
   constructor(hls: Hls, fragmentTracker: FragmentTracker) {
     super(hls, fragmentTracker, '[audio-stream-controller]');
@@ -413,9 +414,17 @@ class AudioStreamController
 
   onLevelLoaded(event: Events.LEVEL_LOADED, data: LevelLoadedData) {
     this.mainDetails = data.details;
+    if (this.cachedTrackLoadedData !== null) {
+      this.hls.trigger(Events.AUDIO_TRACK_LOADED, this.cachedTrackLoadedData);
+      this.cachedTrackLoadedData = null;
+    }
   }
 
   onAudioTrackLoaded(event: Events.AUDIO_TRACK_LOADED, data: TrackLoadedData) {
+    if (this.mainDetails == null) {
+      this.cachedTrackLoadedData = data;
+      return;
+    }
     const { levels } = this;
     const { details: newDetails, id: trackId } = data;
     if (!levels) {

tests/unit/controller/audio-stream-controller.js

@@ -61,6 +61,7 @@ describe('AudioStreamController', function () {
       };
 
       audioStreamController.levels = tracks;
+      audioStreamController.mainDetails = details;
       audioStreamController.tick = () => {};
 
       audioStreamController.onAudioTrackLoaded(Events.AUDIO_TRACK_LOADED, {