Hoppers pointing at minecarts with chest sideways fail to fill the carts depending on the direction.

Steps to reproduce:

1. Place a minecart with chest on a rail
2. Place a hopper pointing at the cart sideways.
3. Put some items into the hopper.
   

What happened:
The hopper doesn't transfer items into the minecart with chest depending on the direction. In my screenshot, the upper two work as expected but the lower two don't.

What I expected:
Hoppers fill the carts regardless of direction.