Command block dispensers don't work

You used to be able to put a command block with an NBT tag in a dispenser, power the dispenser and have the dispenser place down the command block. I tested it today for the first time in ages and it seems to be broken. I built an entire minigame around this concept some time ago so I hope it's a bug and they'll fix it

edit I tested some more, it stopped working in 1.8.6, in 1.8.5 it still worked.