Comment 3 for bug 1115954

I can replicate the problem and i have discovered a different replaced problem.

1. create a PO and receive a product with serial number 123
2. create a PO and receive a product with serial number 456
--so now you have a quantity of 2 of the same product with 2 different serial numbers
3. create a sales order for a quantity of 2 of the product
4. deliver the order and when you hit deliver just enter one of the serial numbers
--i would expect a warning to be raised because there is only 1 qty of each serial number but you are allowed to ship a qty of 2 assigned to 1 serial number

this is the bug i was attempting to originally report

I discovered a second bug while investigating this issue, but i think if one problem is fixed the other one would be also.
In your example, in the stock.picking.out hit the deliver button and when the pop up appears to assign a serial number, you can change the quantity to any value and it will be accepted.

Please let me know if you need more details.