Iron Trapdoors not Have Name

The New Trapdoor not have name, making tile.IrontTrapdoor.name
What I expected to happen was...:
Iron Trapdoor have name

What actually happened was...:
the name is missing,just tile.ironTrapdoor.name

Steps to Reproduce:
1. Change the Gamemode to Creative or create a one
2. Go to at Redstone Section
3. See the iron trapdoor,the name is missing,wooden one have name correct