Play next crashes the app with a single-song queue

[SunBreaker1]

Play next crashes the app with a single-song queue

[OxygenCobalt]

Could reproduce with a single-song queue. This seems like another thing I forgot to test with gapless playback. Thanks for reporting this.

[unrenowned]

I stumbled onto this bug while looking into #733. Not sure if you're already working on this @OxygenCobalt, but thought I'd mention it here anyway.

This bug doesn't just affect single-song queues. It occurs whenever you try to use "Play next" on the last song of a queue. I've put the (truncated) stracktrace you get when the crash happens below:

FATAL EXCEPTION: main
Process: org.oxycblt.auxio.debug, PID: 11379
java.lang.IllegalArgumentException
	at androidx.media3.common.util.Assertions.checkArgument(Assertions.java:40)
	at androidx.media3.exoplayer.ExoPlayerImpl.addMediaSources(ExoPlayerImpl.java:661)
	at androidx.media3.exoplayer.ExoPlayerImpl.addMediaItems(ExoPlayerImpl.java:637)
	at org.oxycblt.auxio.playback.system.PlaybackService.playNext(PlaybackService.kt:380)
...

From this, I think I can see the cause. When you run getNextMediaItemIndex() at the end of a playlist, you get back C.INDEX_UNSET (-1). This value fails the argument check in ExoPlayerImpl.addMediaSources():

checkArgument(index >= 0)

I'm pretty sure you can fix this with a check in PlaybackService.playNext(), something like this maybe?

val nextIndex = player.nextMediaItemIndex
if (nextIndex == C.INDEX_UNSET) {
    player.addMediaItems(songs.map { it.toMediaItem() })
} else {
    player.addMediaItems(nextIndex, songs.map { it.toMediaItem() })
}

If you want I can make a PR for this: just let me know which branch you want me to merge into as I think dev is a little behind on some shuffle order hotfixes.

[OxygenCobalt]

You're probably right about this @unrenowned. Feel free to branch off hotfixes and make a patch PR, I'm super busy right now.

[OxygenCobalt]

Resolved in #748. Will arrive in a hotfix release eventually.