The bug
When certain block entities such as a dropper/dispenser or a command block that contain NBT data for items or a command is either placed manually on a power source or cloned on a power source it will receive power because a repeater gets power from the side of it but the dispenser will not place/drop anything and the command block will not run the command.
How to reproduce
Place down a dispenser or dropper or command block
Put items or a command into the block, depending what it is
Control and middle-click the block to get the block with NBT data
Place this on a power source such as a redstone torch or a redstone block
โ It should run the command or drop/place something but it does not
Note: this also affects note blocks, they won't play a note until they received a block update.
Test command for falling block, insert into a command block and trigger:
summon falling_block ~ ~2 ~ {
BlockState:{Name:"minecraft:stone"},
Time:1s,
Passengers:
[
{
id:"falling_block",
BlockState:{Name:"minecraft:redstone_block"},
Time:1s,
Passengers:
[
{
id:"falling_block",
BlockState:{Name:"minecraft:command_block"},
TileEntityData:{Command:"say Test"},
Time:1s
}
]
}
]
}
Related issue
MC-31100 when using /setblock
to place the block it does not update (and more)
Code analysis
Code analysis by @unknown can be found in this comment on bug report MC-18631.
Linked issues
is duplicated by 12
Comments 19
Confirmed for 1.12 pre-7.
Please consider what I wrote here.
I'm more than willing to take over all 4 bugposts or, preferrably, all of them bundled into the oldest one, if the OP regarding that type of problem (MC-18631) doesn't update it; I would also list all 4 test setups for bug reproduction into that one.
Meri if you would like to take over this bug post you are more than welcome to.
I am not sure what the process to go about transferring it is though
Still an issue in 1.17.1.
Also affects items with BlockStateTag
ย when placed, even when that block is not a block entity, see this video.
This is still a problem but I feel like it is probably going to be marked as "Works as Intended"