Bot Freezes when no cards in hand against Vault

[breppert]

I played multiple Vault's in a turn, and Rattington started with a 5 card hand, discarded all the way down to just 1 card, then discarded that one card against my Vault (but didn't draw a card, because it only discarded one card), leaving it with a zero card hand.

I then played yet another Vault, and Rattington had to make a decision about whether to discard or not (he had a zero card hand), and this broke him.

game #178029 on frankfurt.