Unrecoverable item deletion in shop interface

Repro:

1. Open trade window with a shopkeeper.
2. Add the top row of the items in your inventory to the trade window.
3. Click the "REORDER" button.
4. Switch to a different character (do NOT conclude the transaction).
5. Switch back to the previous character. Note that the items that were previously selected as part of the transaction are now gone.

It seems that when a transaction is canceled, if the inventory slot the item was previously occupying is now occupied by a new item (due to REORDER button), the item is simply deleted.