Unable to play a playlist in go-librespot using the Spotify API

[felixstorm]

When trying to play a playlist using the Spotify API with go-librespot (0.0.17 as well as current master), I get the following error:

ERRO[0062] failed unmarshalling dealer request payload   error="json: cannot unmarshal number into Go struct field RequestPayload.target_alias_id of type string" uri="hm://connect-state/v1/player/command"

I added some debug statements and apparently the JSON that is being received looks like this (formatting for readability):

{
    "message_id": 860749268,
    "target_alias_id": 0,
    "sent_by_device_id": "webapi-cfc0c47944b9400cb5db4f8faf9cbe36",
    "command": {
        "endpoint": "play",
        "context": {
            "uri": "spotify:playlist:37i9dQZF1DX7F6T2n2fegs",
            "url": "context://spotify:playlist:37i9dQZF1DX7F6T2n2fegs"
        },
        "play_origin": {
            "device_identifier": "webapi-cfc0c47944b9400cb5db4f8faf9cbe36"
        },
        "options": {},
        "logging_params": {
            "device_identifier": "webapi-cfc0c47944b9400cb5db4f8faf9cbe36"
        }
    }
}

Changing the type of TargetAliasId from string to uint32 seems to fix this problem, but then the code will panic later on:

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x28 pc=0x916012]

goroutine 1 [running]:
main.(*AppPlayer).handlePlayerCommand(_, {0x334fdf7f, 0x0, {0xc00013d140, 0x27}, {{0xc000015dd0, 0x4}, {0x0, 0x0}, {0x0, ...}, ...}})
        .../go-librespot/cmd/daemon/player.go:223 +0x1f2
main.(*AppPlayer).handleDealerRequest(_, {0xc00029c360, {0xc00013c690, 0x24}, {0x334fdf7f, 0x0, {0xc00013d140, 0x27}, {{0xc000015dd0, 0x4}, ...}}})
        .../go-librespot/cmd/daemon/player.go:336 +0xe8
main.(*AppPlayer).Run(0xc000056800, 0xc0000444e0)
        .../go-librespot/cmd/daemon/player.go:520 +0x565
...

Thereafter I commented out the statements causing the segfault and then it seems to finally work. But unfortunately I do not have any real experience with any of the Spotify Connect APIs to estimate whether my first change is appropriate and why the segfault happens or what to do to fix it...

Also see:

• Spotify plugin not working with Spotify API volumio/volumio-plugins#664
• https://community.volumio.com/t/new-2023-spotify-plugin/63381/113

[devgianlu]

Since Spotify does not know what type target_alias_id should have and we are not using it I've removed it. Also fixed the subsequent problem you had regarding the player options overrides.

[felixstorm]

Great, thanks a lot!