Do song ids retain across server restarts

[itslychee]

I believe the title should explain it all

[MaxKellermann]

What is a "song id"?

[itslychee]

As it's described here https://mpd.readthedocs.io/en/latest/protocol.html#the-queue

Song ids on the other hand are stable: an id is assigned to a song when it is added, and will stay the same, no matter how much it is moved around. Adding the same song twice will assign different ids to them, and a deleted-and-readded song will have a new id. This way, a client can always be sure the correct song is being used.

[naglis]

After a quick look at

MPD/src/queue/QueueSave.cxx

Line 51 in feac1a3

queue_save_song(BufferedOutputStream &os, int idx, const DetachedSong &song)

and

MPD/src/SongSave.cxx

Line 52 in feac1a3

song_save(BufferedOutputStream &os, const Song &song)

and a simple test with addid/deleteid/playlistid commands across MPD restarts it seems that song ids are not written to the state file and thus are not preserved across MPD restarts.

[itslychee]

Thanks for the detailed response! Thankfully I wrote my program to work with any eventual MPD restart so this shouldn't be a problem.