I'm not sure if this is a safety mechanism, but when I shift-click items from the Vacuum Chest inventory into the player's inventory, it won't fill the rightmost slot in the hotbar.

Steps to reproduce:

1. Fill player inventory (except for the hotbar) with items
2. Fill Vacuum Chest inventory with items
3. Open Vacuum Chest inventory
4. Shift-click item in Vacuum Chest inventory to have it automatically placed in the player's hotbar (without having to move the mouse cursor; vanilla mechanic)

What happens:

• The rightmost hotbar slot won't get filled, even if all other inventory slots are already occupied.

EnderCore: 1.7.10-0.1.0.26_beta
Ender IO: 1.7.10-2.3.0.417_beta
Forge: 10.13.4.1448-1.7.10

I fixed a bug like that in the shift-clicking code in spring. Seems the Vacuum Chest is using its own version.

Looks like an off-by-one error...

Yes it was. Also a "we need a copy of this code here, here, here and there" error.

Fixed in 419. Thanks!