The item is deposited when the mouse button is released, rather than first pressed, and is also deposited at the point where the click happened rather than where it ended.

The preferred behaviour would be to have it be deposited where it was first clicked, like with item stacks normally, but when the button is first pressed. Dragging should either do nothing, or continuously empty the bundle's contents into each highlighted inventory slot.

To reproduce:

1. Have a bundle with one or more items inside
2. Click this bundle to pick it up
3. Hold down right click and drag it across several inventory slots
4. Notice that when releasing right click, an item is dropped off where you first clicked
5. Compare this behaviour to a stack of stackable items and note the inconsistency