Item frames can only occupy the same space as fence gates if they're open

The Bug:

Item frames can only occupy the same space as fence gates if they're open.

Steps to Reproduce:

1. Place down a fence gate and ensure it's closed.
2. Attempt to place an item frame on the ground, below the closed fence gate, and take note of how you're unable to.
3. Open the fence gate, and once again, attempt to place an item frame on the ground below it.
4. Take note as to whether or not item frames can only occupy the same space as fence gates if they're open.

Observed Behavior:

Item frames can only occupy the same space as fence gates if they're open.

Expected Behavior:

Item frames would be able to occupy the same space as fence gates even if they're open or closed.