From c7b3fa367b5d2040ee38d52467e39d1d1367b5e9 Mon Sep 17 00:00:00 2001
From: olly <olly@google.com>
Date: Mon, 21 Jun 2021 23:42:35 +0100
Subject: [PATCH] HLS: Fix issue where a live event doesn't transition to
 STATE_ENDED

The problem occurs when the primary media playlist URL switches
from one whose latest snapshot has not yet got the ended tag, to
one whose latest snapshot already has the ended tag. In this case:

- We trigger a redundant load of the ended playlist.
- When the redundant load completes,
  MediaPlaylistBundle.processLoadedPlaylist detects that the
  playlist is unchanged from the one it already has, and so
  doesn't call onPlaylistUpdated.
- PrimaryPlaylistListener.onPrimaryPlaylistRefreshed is never
  called with the new primary. Hence the externally visible primary
  is still the one that hasn't ended. HlsMediaSource therefore thinks
  the event hasn't ended, which in turn prevents the player from
  transitioning to the ended state.

This commit detects when the new primary already has the ended tag.
In this case, we call onPrimaryPlaylistRefreshed directly and remove
the unnecessary playlist load.

Issue: #9067
#minor-release
PiperOrigin-RevId: 380680532
---
 RELEASENOTES.md                                     |  3 +++
 .../hls/playlist/DefaultHlsPlaylistTracker.java     | 13 ++++++++++---
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 1fbce913e7..19ede4cd03 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -65,6 +65,9 @@
         ([#4083](https://github.com/google/ExoPlayer/issues/4083)). Such content
         is malformed and should be re-encoded.
 *   HLS:
+    *   Fix issue where playback of a live event could become stuck rather than
+        transitioning to `STATE_ENDED` when the event ends
+        ([#9067](https://github.com/google/ExoPlayer/issues/9067)).
     *   Fix issue where a new initialization segment, as specified by an
         `EXT-X-MAP` tag in a media playlist, would not be loaded when
         encountered during playback
diff --git a/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/playlist/DefaultHlsPlaylistTracker.java b/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/playlist/DefaultHlsPlaylistTracker.java
index 2a69f5c6af..9ad1cb5934 100644
--- a/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/playlist/DefaultHlsPlaylistTracker.java
+++ b/library/hls/src/main/java/com/google/android/exoplayer2/source/hls/playlist/DefaultHlsPlaylistTracker.java
@@ -339,9 +339,16 @@ public final class DefaultHlsPlaylistTracker
       return;
     }
     primaryMediaPlaylistUrl = url;
-    playlistBundles
-        .get(primaryMediaPlaylistUrl)
-        .loadPlaylistInternal(getRequestUriForPrimaryChange(url));
+    MediaPlaylistBundle newPrimaryBundle = playlistBundles.get(primaryMediaPlaylistUrl);
+    @Nullable HlsMediaPlaylist newPrimarySnapshot = newPrimaryBundle.playlistSnapshot;
+    if (newPrimarySnapshot != null && newPrimarySnapshot.hasEndTag) {
+      primaryMediaPlaylistSnapshot = newPrimarySnapshot;
+      primaryPlaylistListener.onPrimaryPlaylistRefreshed(newPrimarySnapshot);
+    } else {
+      // The snapshot for the new primary media playlist URL may be stale. Defer updating the
+      // primary snapshot until after we've refreshed it.
+      newPrimaryBundle.loadPlaylistInternal(getRequestUriForPrimaryChange(url));
+    }
   }
 
   private Uri getRequestUriForPrimaryChange(Uri newPrimaryPlaylistUri) {