It's similar to bug MC-105049, but holding on the other hand another carrot on a stick. It occurs when switching between them.
What I expected to happen was...:
The durability of the item would have been the same.
What actually happened was...:
The durability was restored.
Steps to Reproduce:
1. Mount on saddled pig.
2. Hold in both hands a carrot on a stick.
3. Use the item.
4. Switch to the other one.
5. The item is "repaired".
This is a dupe of MC-105049:
And the rod in your off hand doesn't change anything because you only use the one in your main hand