nil error when attempting to play a playlist that contains any number of offline files.

Describe the bug Cannot connect to device with spotify when listening to a playlist with any number of offline files.

Version librespot-java-api-v1.5.5

To Reproduce Steps to reproduce the behavior:

1. Restart machine
2. Play a custom playlist that contains Offline files, but play a Spotify track.
3. Try to attach to spocon.
4. See error

Expected behavior Spotify should attach and skip songs that spocon hasn’t downloaded / doesn’t have access to.

Logs

Apr 09 05:12:41 spotipi java[1135]: 2021-04-09 05:12:41,223 TRACE DealerClient:97 - Received request. {mid: hm://connect-state/v1/player/command, key: cbf79024-7486-47ec-9fb9-c6268e81005c, pid: 886375822, sender: 4caaba3413d4673d3929a47864cd72a79628748d, command: {"endpoint":"transfer","data":"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","options":{"restore_paused":"restore","restore_position":"extrapolate","restore_track":"only_current","license":"premium"},"from_device_identifier":"4caaba3413d4673d3929a47864cd72a79628748d"}}
Apr 09 05:12:41 spotipi java[1135]: 2021-04-09 05:12:41,227 DEBUG Player:89 - Received command: Transfer
Apr 09 05:12:41 spotipi java[1135]: 2021-04-09 05:12:41,254 DEBUG Player:379 - Loading context (transfer), uri: spotify:playlist:5RJVwl6dJXaR3IUD2mLQHp
Apr 09 05:12:41 spotipi java[1135]: 2021-04-09 05:12:41,260 TRACE MercuryClient:140 - Send Mercury request, seq: 5, uri: hm://context-resolve/v1/spotify:playlist:5RJVwl6dJXaR3IUD2mLQHp, method: GET
Apr 09 05:12:41 spotipi java[1135]: 2021-04-09 05:12:41,662 TRACE MercuryClient:183 - Handling packet, cmd: MercuryReq, seq: 5, flags: 0, parts: 1
Apr 09 05:12:41 spotipi java[1135]: 2021-04-09 05:12:41,769 TRACE MercuryClient:183 - Handling packet, cmd: MercuryReq, seq: 5, flags: 2, parts: 1
Apr 09 05:12:41 spotipi java[1135]: 2021-04-09 05:12:41,801 TRACE MercuryClient:183 - Handling packet, cmd: MercuryReq, seq: 5, flags: 2, parts: 1
Apr 09 05:12:41 spotipi java[1135]: 2021-04-09 05:12:41,841 TRACE MercuryClient:183 - Handling packet, cmd: MercuryReq, seq: 5, flags: 1, parts: 1
Apr 09 05:12:41 spotipi java[1135]: 2021-04-09 05:12:41,945 ERROR DealerClient:112 - Failed handling request. {key: cbf79024-7486-47ec-9fb9-c6268e81005c}
Apr 09 05:12:41 spotipi java[1135]: java.lang.UnsupportedOperationException: null
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.metadata.UnsupportedId.getGid(UnsupportedId.java:17) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.common.ProtoUtils.lambda$jsonToContextTrack$0(ProtoUtils.java:121) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at java.util.Optional.ifPresent(Optional.java:183) ~[?:?]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.common.ProtoUtils.jsonToContextTrack(ProtoUtils.java:119) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.common.ProtoUtils.jsonToContextTracks(ProtoUtils.java:137) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.common.ProtoUtils.jsonToContextPage(ProtoUtils.java:148) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.common.ProtoUtils.jsonToContextPages(ProtoUtils.java:156) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.mercury.MercuryRequests$ResolvedContextWrapper.pages(MercuryRequests.java:142) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.player.PagesLoader.getPage(PagesLoader.java:95) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.player.PagesLoader.nextPage(PagesLoader.java:129) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.player.StateWrapper$TracksKeeper.initializeFrom(StateWrapper.java:1075) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.player.StateWrapper.transfer(StateWrapper.java:480) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.player.Player.handleTransferState(Player.java:382) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.player.Player.access$300(Player.java:49) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.player.Player$1.command(Player.java:96) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.player.state.DeviceStateHandler.notifyCommand(DeviceStateHandler.java:110) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.player.state.DeviceStateHandler.onRequest(DeviceStateHandler.java:176) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.dealer.DealerClient.lambda$handleRequest$1(DealerClient.java:107) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.common.AsyncWorker.lambda$new$0(AsyncWorker.java:20) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at xyz.gianlu.librespot.common.AsyncProcessor.lambda$submit$1(AsyncProcessor.java:40) ~[librespot-java-api-v1.5.5.jar:1.5.5]
Apr 09 05:12:41 spotipi java[1135]:         at java.util.concurrent.FutureTask.run(FutureTask.java:264) [?:?]
Apr 09 05:12:41 spotipi java[1135]:         at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) [?:?]
Apr 09 05:12:41 spotipi java[1135]:         at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) [?:?]
Apr 09 05:12:41 spotipi java[1135]:         at java.lang.Thread.run(Thread.java:834) [?:?]

[devgianlu]

That should be fixed too.

I’ve also added the snapshots link to the README.

[devgianlu]

Should be good now.