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MC-51340

Certain blocks do not update when falling, placed or cloned next to a power source

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

  1. Place down a dispenser or dropper or command block

  2. Put items or a command into the block, depending what it is

  3. Control and middle-click the block to get the block with NBT data

  4. 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.

Related issues

MC-18631 Some redstone components (block entities) do not update themselves when placed MC-73882 Dispenser does not look for redstone power when placed MC-75576 Redstone Repeater Bug MC-80901 Landed Falling Block does not trigger redstone updates for block entities (Command Blocks, ...) MC-86663 Chain Command Block not powered by Redstone Block when Chain Block is placed next to or on a Redstone Block before being turned from Impulse to Chain. MC-87131 Repeated Command Block Activation Issues MC-88681 when summoning falling sand riding falling sand upper most command block does not activate MC-91510 All command blocks DO NOT respond to redstone blocks when placed w/ custom tag MC-105522 Detecting wool in a commandblock MC-156919 Block doesn't get triggerd by redstone after you placed it MC-233642 Items with BlockStateTag placed will not update redstone. MC-266379 Some blocks stay unpowered when placing adjancent redstone blocks

Comments

gentlegiantJGC

This is still a problem but I feel like it is probably going to be marked as "Works as Intended"

galaxy_2alex

Reopened, thanks.

Frank Steffahn

This behavior is somewhat useful as you can use command blocks as block update detectors

Meri Diana

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.

gentlegiantJGC

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

Meri Diana

Hello there!

If you're fine with it, usually the moderators wouldn't oppose transferring and might do so as soon as they see it, unless there'll be a merge of all bugposts including this one, which anyone else might get assigned to, no idea, up to them.

Whenever someone (like we did now) does any changes to a bugpost, including comments, it seems to get into their update feed, so they will see our comments here eventually and then make a decision ๐Ÿ™‚

Thank you, have a good day and take care!

wobst.michael

Gave ticket to @unknown

Panda4994

Confirmed for 1.13pre4.

Panda4994

Confirmed for 1.13-pre6.

Panda4994

Confirmed for 1.13-pre7.

Panda4994

Confirmed for 1.13-pre8.

Panda4994

Confirmed for 1.13.

Kraif

Confirmed for 1.13.1.

CreeperMagnet_

Confirmed for 1.16.4 and most recent snapshot (20w48a).

Giovanni Lanzarote

confirmed for 20w49a

Giovanni Lanzarote

Still an issue in snapshot 20W51A

Giovanni Lanzarote

Still an issue in snapshot 21w03a

Hayden Wong

Still an issue in 1.17.1.

Also affects items with BlockStateTagย when placed, even when that block is not a block entity, see this video.

ampolive

Since this also affects blocks which are not block entities, such as composters and note blocks, I have updated the title to reflect this.

gentlegiantJGC

Meri Diana

(Unassigned)

Confirmed

Platform

Low

Commands

/clone, block-entity, block-update, command_block, dispenser, dropper, note_block, powered, redstone

Minecraft 14w11b, Minecraft 14w17a, Minecraft 14w18a, Minecraft 14w30b, Minecraft 14w30c, ..., 1.17 Pre-release 3, 1.17.1, 1.18.2, 1.19.1 Pre-release 5, 1.20.2

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