Not getting an error while trying to create shipment of already shipped item

[zahmed-f3]

Steps to reproduce

1. Install Magento version 2.0.4.
2. Create an order with single item having quantity one like below:
   
3. Create a Shipment via Rest API like below:
   POST: /rest/V1/shipment/
   { "entity" : { "orderId" : 5, "items" : [{ "orderItemId" : 5, "qty" : 1 } ] } }
4. Try to create Shipment multiple times using above call with same data.

Expected result

After creating first shipment, it should throw an exception if the quantity of the item in the order has been shipped.

Actual result

Multiple Shipments is creating with single item having quantity one like below:

[piotrekkaminski]

Internal issue MAGETWO-53558

[veloraven]

Internal ticket was closed as a duplicate.
Corresponding internal tickets are already closed as they were fixed for develop branch.
Closed.