This bug will cause two of the same item to be consumed from two slots on the hotbar when consumed.

Steps to reproduce:

1) Give yourself a stack of any item that can be used with right click (cooked beef, cooked pork, etc)

2) Split the stack into two hotbar slots that are next to each other (see attached image)

3) Hold one of the stacks

4) Begin consuming the stack (right click and hold)

5) While in the process of consuming the item, scroll to the other slot containing the same item.

When you finish consuming the item, one item from each of the two stacks will be consumed.

Expected behavior:

Only one of the items should be consumed.

If you test this with a bow/trident/non-food, the item that was originally used to perform the action is correctly damaged/thrown.

Note: I systematically tested versions for this regression, and have found that it was first introduced in 1.14.4-pre1. Prior to this version, switching hotbar slots always reset the progress of any usable item.