Merchants: wrong items from vendor

[Thrynn]

After the rollback i noticed that the aviak vendor in SK gives you a different item than you purchased. Bought a small gem to reduce coin weight, and, recieved some kind of jewelry when i purchased, tried it again received a preserved splitpaw eye (in game name: thrynn)

[Uthgaard]

This bug has been around for a while, but I dragged Spirell along to help me test it. This is with all vendors btw. Found the exact steps to reproduce this.

Multiple people go to one vendor. If one person buys or sells items to the vendor, causing the vendor to gain or lose a non-permanent item from stock, the table entries shift places.

Other players who had that window open will still purchase the correct items from the list, while all players still have their window open.

The moment the player that caused the vendor stock to shift closes the window, any players with their window still open will purchase incorrect items. Closing the window only executes that individual's changes.
I tested to see whether it would happen if someone else closed their window after I cleared out items, and it didn't.

So closing the window is the event that runs all of the queries on the actual table, maybe could give each spot in vendor stock an absolute reference in the table, since it's limited to a fixed amount of items in display, instead of allowing them to shift with each table update.