[MCPE-13608] Redstone components update when world is reloaded Created: 17/Feb/16  Updated: 08/Mar/24  Resolved: 04/Jun/17

Status: Resolved
Project: Minecraft (Bedrock codebase)
Component/s: None
Affects Version/s: 0.14.0, 0.14.0 Beta 7, 0.14.2, 0.15.6, 0.16.0, 0.16.1, 0.17.0.1, 0.16.2, 1.0.0.0, 1.0.0.1, 1.0.2, 1.0.3, 1.0.4.0, 1.0.4.1, 1.0.4.11, 1.0.5.13, 1.0.6.0, 1.0.5.54, 1.1.0.0, 1.0.7.0, 1.1.0.8, 1.1.0.9
Fix Version/s: 1.1.0.55

Type: Bug
Reporter: Jim
Resolution: Fixed Votes: 9
Labels: redstone, world-loading

Attachments: Zip Archive MCPE-15779.zip     PNG File Screenshot_2016-02-17-18-24-51.png    
Issue Links:
Duplicate
is duplicated by MCPE-13609 State of Redstone not saving when wor... Resolved
is duplicated by MCPE-14233 Redstone components update upon reloa... Resolved
Relates
relates to MCPE-29548 Relogging can cause observers to emit... Open
relates to MCPE-13270 Comparators measuring a non-empty con... Resolved
relates to MCPE-13413 Active unpowered locked repeaters bec... Resolved
relates to MCPE-15779 Redstone does not load chunks Resolved
relates to MCPE-17464 Extended pistons retract for a second... Resolved
relates to MCPE-18570 Schrodinger's Steve Resolved
relates to MCPE-179412 Dispenser with bucket may fail to pic... Open
relates to MCPE-20159 Active redstone signals are not resto... Resolved
Confirmation Status: Confirmed
Platform: Phone - Android - LG G2
CHK:
ADO: 55369

 Description   

In my survival world, I have a lever that controls dispensers on a semi automatic wheat farm. The dispensers fire water buckets. I Have a circuit seen below which activates on the rising and falling action of the lever. When I am in the game, the circuit works as intended but if I relog the game (quit to title and join back) the dispenser will fire the bucket and stay in that state. I assume it is the Redstone torches that do not save state as I leave the game.

From MCPE-14233:

Upon loading a world, redstone components update. The redstone may change based on an unloaded chunk, causing it to turn off when it should be being powered by something in the unloaded chunk next to it. To reproduce: make a long line of redstone with repeaters, power one end, then stand at the other end and lower your render distance. Then reload the world. The redstone will turn off, then turn back on as you load the component powering it. This affects all redstone components that I am aware of, including pistons. It tends to break contraptions as one half may update while the other is unloaded, often sending redstone contraptions into a clock.

Steps to reproduce:
1. Create a flat creative world.
2. Place a lever, turn it on, and then place a long line redstone dust and repeaters extending far out some distance outside of chunk-loading range, and then make the wire do a u-turn and come back to the start. Make sure there are repeaters so that the signal can go all the way.
3. Exit the world and reload it.
4. Wait a little while, and you'll notice that the returning end of the wire will turn off, as the redstone updates and can't find a power source, since the connection between the start and end is unloaded, and also because of MCPE-15779. (Though even if that was fixed there might still be a moment where the dust becomes unpowered while the chunks are still being loaded.)

This effect can also sometimes be seen in cases where a piston is being powered by a source in another chunk, and the chunk with the piston loads first. This is more difficult to reproduce in a world, though.


Edit by depressed-pho:
The second part of the original description is WAI: MCPE-15779.
The first part, redstone components being ticked upon loading chunks, is the real issue. It is probably a leftover from the past behavior: state of redstone components used to be forgotten upon unloading chunks, and in order to recover it the game ticked all of them on the chunk reload. Now their state seems to be correctly saved in the file so they need not to be ticked, and doing so also causes the very problem: components in unloaded chunks affect the entire contraption. To reproduce this,

  1. Open a world attached to MCPE-15779.
  2. Load all the chunks where the entire circuit resides in.
  3. Return to the point where the piston is placed.
  4. Close the world and open it again.
  5. Observe that the piston momentarily extends and then retracts. Ideally the piston and the line of dust should stay activated even though the middle part of the dust line is in unloaded chunks, because their last state (active) should be saved in the file and the game only needs to restore it.


 Comments   
Comment by PHO [ 04/Jun/17 ]

Fixed in 1.1.0.55! Yay!

Comment by Zeb [ 07/Oct/16 ]

Affects 0.15.90.8 (0.16.0 beta build 5). Interestingly, I've only had this happen to me on Pocket Edition, and it isn't happening to me on Win10 0.15.10. I may need to do some more testing, though.

Ignore this comment, I believe I was improperly testing this bug. I'll try and properly test it later...

Comment by Jim [ 10/Aug/16 ]

Yes, Azelef is right this still is a major problem. I mistakenly typed 0.15.2 insteard of 0.15.4

I have noticed in my testing that this happens with redstone blocks with a torch on top as well.

Comment by Azelef [ 10/Aug/16 ]

Confirmed in 0.15.4, please reopen.

Comment by AMAN4700 [ 08/Aug/16 ]

I'm sorry sir, 0.15.4 is the current version, not 0.15.2.

Comment by Jim [ 08/Aug/16 ]

Still happens in 0.15.2

I tried in a different world and this happened as well.

Thanks,
Jim

Comment by AMAN4700 [ 08/Aug/16 ]

Please respond and add the current version if you can reproduce this issue.

Comment by Jeff Jewett [ 15/May/16 ]

Yes this bug is still around in 0.14.2 for my iPhone 4- I have tested numerous combinations of redstone, torches, repeaters, comparators and dispensers. Most times there is a single pulse right as the world opens that activates the dispenser. My guess is that the powered state of the dispenser is not saved so when you open the world it activates it again. Please fix. This causes damage when you have TNT dispensers.

Comment by J. C. [ 29/Feb/16 ]

Yes, unfortunately this still occurs same as before.

Comment by AMAN4700 [ 28/Feb/16 ]

Does this bug still appear in 0.14.0? If so please respond.

Comment by PHO [ 18/Feb/16 ]

Never mind, that happens often.

Btw this "Relates to" MCPE-13270 and MCPE-13413 but it is possible that they are all the same bug.

Comment by Jim [ 17/Feb/16 ]

I apoligise I uploaded this 3 Times as my phone does not seem to be giving me confirmation of a successful post.

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