It seems after playing around with the latest snapshot some worlds containers got reset , this is inventory chests and furnaces
and also got rid of world borders
i only played the snapshot on a newly created world and didn't open any other worlds with the snapshot
If you played a 1.7.9 world on snapshots then reverted back to 1.7.9 after you were done, your inventory would be erased along with all the chests, since reverting is not the same as playing in a newer version and may cause major problems in your world.