If you try to place end portal, the portal isn't placed. Instead, the block is air.
How to reproduce :
Do one of the commands:
/fill ~-1 ~-1 ~-1 ~1 ~-1 ~1 end_portal
/setblock ~ ~-1 ~ end_portal/fill ~-1 ~-1 ~-1 ~1 ~-1 ~1 end_portal
/setblock ~ ~-1 ~ end_portalEDIT : If you place manually the portal block, the portal despawn.
Comments 6
You aren't supposed to do it before the dragon is dead. I tried in 14w21a and you should be able to place them after its death.
I think the fact that it replaces the blocks with air can definitely be considered a bug, no matter what the rest of the issue is considered (although I also think that seems like a bug).
Confirmed