Mending not working

Put the summary of the bug you're having here

What I expected to happen was...:
I would gain experience along with healing a tool with mending.

What actually happened was...:
Experience gained is not applied to experience bar when holding a mending tool.

Steps to Reproduce:
1. Have a mending tool (i.e. a diamond sword with mending)
2. gain experience (i.e. killing a mob)