Horse Riding Error

I was checking out the new horses, after I've trained one, put diamond horse armour on it, and then put a saddle on it, I rode it for a while, logged off then logged back on.

What I expected to happen was...:
I would be dismounted from the horse, and everything would be fine.

What actually happened was...:
I was still riding the horse, and every step I took my character would shake rapidly.

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...
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