Sorry if this isn’t the proper forum for this, but the bug subfora seem to have been archived…
I’ve done a quick search on the forum and on Google, but found no results matching this particular bug. Maybe it’s new.
Also, I’ve only tested it in the Black Pits atm.
The bug: if a shop has only a limited amount of a particular item (say, a scroll, potion or magic weapon) this can be easily bypassed. It is possible to buy (maybe also steal, I haven’t checked that) the item and not have it subtracted from the shop’s inventory.
It may also possibly apply to containers, but I don’t have one in the Black Pits, so I can’t test that as well.
How to reproduce:
1) enter the shop
2) buy an item that the shop has limited stock of
3) switch to character inventory screen (or any other screeb, as long as you don’t press the “Done” button)
4) switch to main game screen
—> now you have the item and the shop’s stock state change hasn’t been applied. You can buy the item again. And again. And again.