"sounds" folder in subpacks doesn't work

The sounds folder within subpacks is able to tell that there is a .ogg file located within it however, when trying to play it, it will be completely silent.

Steps to reproduce:
1. Download attached file and run it in minecraft
2. make sure the subpack is set to "No subpack music"
3. Do "/playsound music.game.end @p"
4. Game will play end music
5. exit world and change subpack to "Subpack music"
6. Do "/playsound music.game.end @p"
7. Game will not play any music

Observed results:
1. "no subpack music" will play the games default end music
2. "subpack music" will not play anything

Expected results:
1. "no subpack music" will play the games default end music
2. "subpack music" will play the games modified end music