Fishing rod doesn't take damage if you switch to another hotbar slot after casting

Put the summary of the bug you are having here

What I expected to happen was that the fishing rod spent over time.

What is the fishing rod without spending, ie I use it infinitely

1. Put the fishing rod in a hotbar slot.
2. Cast it on the ground or hook a mob.
3. Then, switch to another hotbar slot.
4. Fishing rod will not damaged, so I can use it for infinitely hooking mobs.

PS: sorry for google translator, BR and'm not speak English