Breaking various things yields different results.
Minecart (Plain): entity.MinecartRideable.name
Minecart w/ Chest: container.minecart
Minecart w/ Furnace: entity.MinecartFurnace.name
Minecart w/ TNT: entity.MinecartTNT.name
Minecart w/ Hopper: container.minecart
All of these have the same id:"" tag, but their tag:{display:{name:""}} tag is screwed up. Crafting and placing and other things are not affected, so it seems to be purely graphical. (Minecarts don't stack, so that can't be screwed up.)
Hoppers flowing into other hoppers now overrides the "powered; I shouldn't accept items" thing... sounds like an easyish fix.
Can confirm in 51b.
This breaks sorting systems! Oh noes!
@ampolive no - this is just about mobs with fractional health points. "how much damage can this mob survive" is the hp rounded up to the next integer, but the hp for the size of the health bar is rounded to the nearest integer (and then from there, down to an even integer, which is what MC-200102 concerns, but to my knowledge that's intentional)