Giving Pokemon an item via newbox menu hangs game (item-newbox branch)

[MarioBones]

If you try to give an item to a Pokemon via the PC the game hangs. If you leave it long enough a list of items will load but it will be full of invalid items and quantities all in the same pocket

Steps to reproduce:

1. Use the PC in a Pokemon Centre
2. Select Bill's PC
3. Select a Pokemon with no Held Item
4. Select Item -> Give

Affected branches:
item-newbox (regular newbox branch works fine)