Can't break minecart while sitting in it

What should happend is that I can break it so I don't keep going on a rail if I want to stop

I couldn't break the minecart on the rail and I had do click shift to go out from it and then break it. I also tested this in creative mode and I got the same result

Steps to Reproduce:
1. Sit in a minecart on a rail or on the ground
2. Try to break it.
3. and you will see whats happend..