playlist(s) fail to update ("skipping forceUpdate since playlist is being updated")

[simon-weber]

I've gotten into this state twice in the past 24 hours or so. It looks like the playlist update lock is being acquired and never released due to errors during a previous update. Here's an example:

lock [auto] not heard recently
background.js:123 [auto] not heard recently found 592
background.js:125 first is Object
https://play.google.com/music/services/loaduserplaylist?... Failed to load resource: net::ERR_NETWORK_CHANGED
googlemusic.js:47 request failed: https://play.google.com/music/services/loaduserplaylist?format=... Array[2] Objectabort: ... @ googlemusic.js:47
background.js:217 periodic update for 17736759431493700887
background.js:51 get poll for 17736759431493700887 1452397617030000
background.js:31 index for 17736759431493700887 1
googlemusic.js:62 getTrackChanges 1452397617030000
googlemusic.js:111 1 "tracks"
googlemusic.js:114 Object
background.js:61 done with diff upsert of 1
background.js:63 done with diff delete of 0
background.js:43 set poll for 17736759431493700887 1452445341027000
background.js:153 renaming to [auto] frequent metal
background.js:31 index for 17736759431493700887 1
googlemusic.js:124 updatePlaylist Object
background.js:177 skipping forceUpdate since playlist is being updated: [auto] not heard recently

I had a feeling this would happen because the unlock isn't in something like a finally, but I didn't think it'd be as common as this.

[simon-weber]

I'm surprised I managed to trigger this twice, since the timing is actually pretty precise: you need to lose connection in between the request for changes and the request to update a playlist. Fixing it is straightforward.

[simon-weber]

This can also happen when Google returns an unexpected response.

For example, this just crashed on a response [[4, 2, 2]] (which I think signals some kind of error on Google's end).