Upon putting items in an anvil on a multiplayer server while it restarts the item will disappear completely when you log back on.
It occurred in The End. Was unable to test this out in other dimensions either.
I was unable to test on current release version of the game.
Also, sorry in advance if this is a duplicate. I did my best searching with nothing coming up.
Comments 2
Related to MC-13491. If items can't be saved in the anvil (or crafting table), then they shouldn't be removed from the player's inventory until they're altered, removed, etc. Or they should be considered to be in the world, like how items are ejected from the crafting table if you leave them there but close the crafting interface.
The game can't save stuff in the anvil, much like a crafting table, because it is not a tile entity. If the server is forced to stop, there is nothing it can do.