Javelin Bug

If you are holding a javelin(I assume any kind) and prepare to throw it, when it is completely drawn back and you release it, if you scroll-wheel to the next item in the hot bar it will delete the existing item and replaces it with a duplicate javelin (again I assume any kind of javelin that is thrown). This glitch will happen even if nothing is in the next slot and only happens if you scroll-wheel in the ascending slot.