Minor Open box of donuts in backpack is invisible/unremoveable

[The Grim Sleeper]

If you (accidentally) open a box of donut inside of a backpack, it's sprite becomes invisible. You can still take donuts out of the box and even put them back in, but it is no longer possible to click-drag the box itself.

[Roomba]

Hand this happen with a carton of eggs, too. Also, despite the egg carton being still ‘there’ (I could take eggs out of it and put them back into the invisible carton), the slot was treated as empty backpack-wise and items would overlay themselves on top of it.

[warcrimes]

A similar and probably related bug can be reproduced as follows.
1. Enter locker, close it
2. Open backpack
3. Click-Drag any item, container or otherwise, from the bag to the locker ( you )
the item now occupies no slot, and its sprite moves to slot 1. Repeat to stack as many sprites as you wish

BONUS bug: you can't grab your backpack anymore.