MCPE-52586Clone command does not update observers consistently
If you use a command block to issue a /clone command whose destination includes a block being watched by an observer, the observer usually detects a change and outputs a signal. (This occurs even if the command didn't clone any blocks, or if the destination block contained air both before and after the command; this is reported as the related issue MCPE-52581.) However, if the observer is in a different chunk from the destination block, it does not detect a change even if the command actually replaced the original block with a different one.
The attached world demonstrates this issue. A square of quartz blocks identifies the interior of a chunk. The chunk contains 5 cross-shaped devices, each with an associated command block. One cross is in the center, the others are at the corners of the chunk. When activated, the command block clones a diamond block into the center of the cross. The arms of the cross consist of observers watching the center and redstone lamps to make it easily visible which observers output a signal.
Steps to reproduce:
- Open the attached world.
- While watching the redstone lamps, press the button on one of the command blocks.
Expected results:
The clone command places a diamond block in the center of the cross, triggering a detection in each observer, which activates all four redstone lamps.
Actual results:
Only the device in the center acts as expected. For the devices in the chunk corners, the clone command apparently only triggers the observers that are in the highlighted chunk. If you manually place or break the block in the center of the cross, all four observers are triggered as expected.
Linked Issues
![[Mod] GoldenHelmet](../../../data/avatars/users/18951.svg){kind=small}
![[MCPE Mod] Auldrick](../../../data/avatars/users/10122.svg){kind=small}
Created Issue:
Clone command does not update observers consistently
If you issue a /clone command whose destination includes a block being watched by an observer, the observer usually detects a change and outputs a signal. (This occurs even if the command didn't clone any blocks, or if the destination block contained air both before and after the command; this is reported as the related issue
MCPE-52581.) However, if the observer is in a different chunk from the destination block, it does not detect a change even if the command actually replaced the original block with a different one.The attached world demonstrates this issue. A square of quartz blocks identifies the interior of a chunk. The chunk contains 5 cross-shaped devices, each with an associated command block. One cross is in the center, the others are at the corners of the chunk. When activated, the command block clones a diamond block into the center of the cross. The arms of the cross consist of observers watching the center and redstone lamps to make it easily visible which observers output a signal.
Steps to reproduce:
- Open the attached world.
- While watching the redstone lamps, press the button on one of the command blocks.
Expected results:
The clone command places a diamond block in the center of the cross, triggering a detection in each observer, which activates all four redstone lamps.
Actual results:
Only the device in the center acts as expected. For the devices in the chunk corners, the clone command apparently only triggers the observers that are in the highlighted chunk. If you manually place or break the block in the center of the cross, all four observers are triggered as expected.
If you use a command block to issue a /clone command whose destination includes a block being watched by an observer, the observer usually detects a change and outputs a signal. (This occurs even if the command didn't clone any blocks, or if the destination block contained air both before and after the command; this is reported as the related issue
MCPE-52581.) However, if the observer is in a different chunk from the destination block, it does not detect a change even if the command actually replaced the original block with a different one.The attached world demonstrates this issue. A square of quartz blocks identifies the interior of a chunk. The chunk contains 5 cross-shaped devices, each with an associated command block. One cross is in the center, the others are at the corners of the chunk. When activated, the command block clones a diamond block into the center of the cross. The arms of the cross consist of observers watching the center and redstone lamps to make it easily visible which observers output a signal.
Steps to reproduce:
- Open the attached world.
- While watching the redstone lamps, press the button on one of the command blocks.
Expected results:
The clone command places a diamond block in the center of the cross, triggering a detection in each observer, which activates all four redstone lamps.
Actual results:
Only the device in the center acts as expected. For the devices in the chunk corners, the clone command apparently only triggers the observers that are in the highlighted chunk. If you manually place or break the block in the center of the cross, all four observers are triggered as expected.
relates to
![[Mod] LateLag](../../../data/avatars/users/92884.png){kind=small}
![[Mojang] Mega_Spud (Jay Wells)](../../../data/avatars/users/92696.png){kind=small}
![[Bot] Arisa](../../../data/avatars/users/43007.png){kind=small}
![[MCQA] v-weszaj](../../../data/avatars/users/18941.svg){kind=small}
If you use a command block to issue a /clone command whose destination includes a block being watched by an observer, the observer usually detects a change and outputs a signal. (This occurs even if the command didn't clone any blocks, or if the destination block contained air both before and after the command; this is reported as the related issue
MCPE-52581.) However, if the observer is in a different chunk from the destination block, it does not detect a change even if the command actually replaced the original block with a different one.The attached world demonstrates this issue. A square of quartz blocks identifies the interior of a chunk. The chunk contains 5 cross-shaped devices, each with an associated command block. One cross is in the center, the others are at the corners of the chunk. When activated, the command block clones a diamond block into the center of the cross. The arms of the cross consist of observers watching the center and redstone lamps to make it easily visible which observers output a signal.
Steps to reproduce:
- Open the attached world.
- While watching the redstone lamps, press the button on one of the command blocks.
Expected results:
The clone command places a diamond block in the center of the cross, triggering a detection in each observer, which activates all four redstone lamps.
Actual results:
Only the device in the center acts as expected. For the devices in the chunk corners, the clone command apparently only triggers the observers that are in the highlighted chunk. If you manually place or break the block in the center of the cross, all four observers are triggered as expected.If you use a command block to issue a /clone command whose destination includes a block being watched by an observer, the observer usually detects a change and outputs a signal. (This occurs even if the command didn't clone any blocks, or if the destination block contained air both before and after the command; this is reported as the related issue
MCPE-52581.) However, if the observer is in a different chunk from the destination block, it does not detect a change even if the command actually replaced the original block with a different one.The attached world demonstrates this issue. A square of quartz blocks identifies the interior of a chunk. The chunk contains 5 cross-shaped devices, each with an associated command block. One cross is in the center, the others are at the corners of the chunk. When activated, the command block clones a diamond block into the center of the cross. The arms of the cross consist of observers watching the center and redstone lamps to make it easily visible which observers output a signal.
Steps to reproduce:
- Open the attached world.
- While watching the redstone lamps, press the button on one of the command blocks.
Expected results:
The clone command places a diamond block in the center of the cross, triggering a detection in each observer, which activates all four redstone lamps.
Actual results:
Only the device in the center acts as expected. For the devices in the chunk corners, the clone command apparently only triggers the observers that are in the highlighted chunk. If you manually place or break the block in the center of the cross, all four observers are triggered as expected.
relates to
The fact that observers detect failed cloning attempts may be related to MCPE-29548. My thought is that block placing commands may use a part of the chunk loading function rather than the block update function that runs when a chunk is ticked. This could explain MCPE-52586 as well.
The behavior of the clone command here is similar to other block placement commands (setblock, fill) insofar all of these usually only trigger block updates within the chunk in which they place blocks. This fact can be used to test/demonstrate the possibility of breaking various structures that cross chunk borders during chunk loading. Examples I am aware of are provided in Automatic chunk border break.mcworld
However, setblock and fill do trigger block updates across chunk borders when they place blocks on chunk borders. In this way they differ from clone.
Thank you for your report!
However, this issue has been temporarily closed as Awaiting Response
Is this still an issue in the latest version? If so, can you please add it to the affected versions (or mention it if you are not the reporter).
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The behavior hasn't changed in 1.16.
It's not really a problem for me at the present time, but it makes the results of the /clone command dependent on where the target location is in relation to chunk boundaries, which is potentially a problem for worlds, such as Marketplace worlds, that use command blocks.