Put the summary of the bug you're having here

What I expected to happen was...:
that the character doesn't get stuck in the fence gate.

What actually happened was...:
that the character got stuck in the fence gate.

Steps to Reproduce:
1. Open the fence gate and walk in it
2. Close it when the character is almost out of the fence gate.
3. Now you can't escape, place blocks or open the gate again, you are stuck unless you go in to spectator or creative mode.

Update: The glitch works on trapdoors and even on Stone-walls.

How to do with Stone-Wall:

Place 3 Stone-walls in a line.

Walk against to the middle one.

Place something on top of that middle wall (like a torch or string, on F3, the block-status "up" is changed from "false" to "true")

P.S.: The World file backup (fence gate) is in the attachments, Cheats are on, so you can escape with spectator or creative.