[MC-846] Dispenser and Dropper shooting out when updated Created: 27/Oct/12  Updated: 27/Mar/17  Resolved: 05/Mar/13

Status: Resolved
Project: Minecraft: Java Edition
Component/s: None
Affects Version/s: Minecraft 1.4.1, Minecraft 1.4.2, Minecraft 1.4.5, Snapshot 12w50a, Minecraft 1.4.6, Minecraft 1.4.7, Snapshot 13w01a, Snapshot 13w02b, Snapshot 13w03a, Snapshot 13w09c, Snapshot 13w10a
Fix Version/s: Snapshot 13w10b

Type: Bug
Reporter: [YT]ZeBests Assignee: [Mojang] Jeb (Jens Bergensten)
Resolution: Fixed Votes: 21
Labels: dispenser, dropper

Attachments: PNG File 2013-01-18_19.05.18.png     PNG File 2013-03-04_22.55.20.png     PNG File 2013-03-04_22.55.21.png     PNG File 2013-03-04_22.55.21_2.png     JPEG File screenshot-1.jpg    
Issue Links:
Duplicate
is duplicated by MC-5955 Redstone torches' placed block powers... Resolved
is duplicated by MC-6287 Dispenser glitch Resolved
is duplicated by MC-6293 4 tick clock is made when Comparators... Resolved
is duplicated by MC-6813 Dispensers Comparators pointing at th... Resolved
is duplicated by MC-7227 Comparator makes Dispenser mad Resolved
is duplicated by MC-7262 Charged dispenser reacts to diagonal ... Resolved
is duplicated by MC-7562 Redstone-Loop/Dispenser Bug Resolved
is duplicated by MC-7649 Rapid pulse bug with dispensers & dro... Resolved
is duplicated by MC-7696 Camparator doing crazy stuff Resolved
is duplicated by MC-7724 Comparator causing update behind itse... Resolved
is duplicated by MC-7910 Whopper bug Resolved
is duplicated by MC-8669 Dropper responding to redstone clock ... Resolved
is duplicated by MC-8918 Powered Droppers and Dispensers fire ... Resolved
is duplicated by MC-9005 This Causes Dispensers to constantly ... Resolved
is duplicated by MC-9054 Inconsistent behaviour with repeaters... Resolved
is duplicated by MC-9508 While a dropper is powered, any redst... Resolved
is duplicated by MC-10340 weird repeater update Resolved
is duplicated by MC-654 Tripwire Updating Dispensers incorrec... Resolved
is duplicated by MC-2812 When I am Pressing button, Dispenser ... Resolved
is duplicated by MC-4223 dispenser shoots twice when connected... Resolved
is duplicated by MC-4298 Dispenser dispenses 2 times probably ... Resolved
is duplicated by MC-4341 Dispenser bug Resolved
is duplicated by MC-4572 putting a tripwire hook on a dispense... Resolved
is duplicated by MC-4843 Dispenser Glitch Resolved
Relates
relates to MC-10948 Dispensers continually shoot/use cert... Resolved
relates to MC-55623 An un-powered dispenser keeps shootin... Resolved
CHK:
Confirmation Status: Confirmed

 Description   

How to reproduce this bug:
1. place a dispenser with about 64 items in it
2. power it; shoots out one.
3. Place redstone (not connected to the input that is powering the dispenser) or any other block near the diespenser (radius of 2 or 3 blocks)
4. It shoots out another item.

ATTENTION!
screenshot-1.jpg is the bug I'm talking about, not others! Comparators are intended to make constant updates, and dispenser BUD.jpg is acutally not BUD, because the redstone dust is powering the block and that powers the dispenser. I would like to remove the picture but I don't know how and I don't even know if I can.



 Comments   
Comment by asdf [ 07/Mar/13 ]

@William Pearson: One of the goals of the Redstone Update was to make Redstone more reliable and self-consistent. No other block activates on redstone updates, and the behavior didn't even make sense. Yes, it IS all bug.

Comment by Anon Ymus [ 06/Mar/13 ]

There is a way to rewire everything so that it works with the new behavior. It is always better to have something be larger than founded on bugs. And if you don't like the behavior, you can always run 13w10a.

Comment by bruno rodrigues [ 04/Mar/13 ]

http://youtu.be/qyzFkmp3G3c that's what it does on the latest snapshot

Comment by bruno rodrigues [ 04/Mar/13 ]

The powered dispenser dispense the lava cause of an update in front of it and don't stop until we remove the bucket from the dispenser. The dispenser act like a BUD but not only with redstone

Comment by David Whitcomb [ 01/Mar/13 ]

I was making a contraption with a dropper and a Comparator. The redstone dust from the comparator(changing the redstone strength) was causing a update, which messed up the timing/item count. Hopefully his bug gets fixed soon. Vote for it.

Comment by Stephen Train [ 11/Feb/13 ]

Allow me to clarify: I think that the dispenser update bug should be fixed for the same reasons that the comparator bug was fixed.

Comment by [YT]ZeBests [ 11/Feb/13 ]

um...Comparator are already fixed so that it won't constantly update blocks Which made the redstone more consistent.

Comment by asdf [ 11/Feb/13 ]

I couldn't have said it better myself.

Comment by Stephen Train [ 11/Feb/13 ]

This bug is widely used by the community, however I believe it should be fixed. As with the 'constantly updating comparator' issue it causes far more issues than it solves. One of the stated goals of 1.5 is to make redstone logic 'more predictable and consistent', and fixing this issue is a perfect way to do that.

Comment by [YT]ZeBests [ 09/Feb/13 ]

Comparator was suppose to update blocks that are in contact with it (If my English makes sense); But this has been changed in 13w05a. But anyways thanks and hopefully people won't get confused when they see this (When the hell is Mojang going to see this?)

Comment by Anon Ymus [ 09/Feb/13 ]

It is actually the same problem, but we don't need tons of screenshots. Deleted.

Comment by [YT]ZeBests [ 09/Feb/13 ]

Do remove the picture if you can, or tell me how to (since I started the issue). That is not a bug, or at least not what I'm trying to say anyways. If you consider this as a bug, there won't be a compact piston elevator. What I'm trying to say in this issue was screenshot-1.jpg, not other pictures from people who doesn't understand redstone.

Comment by Brett Prairie [ 08/Feb/13 ]

Have added a photo. If I power the signal, all three droppers fire one item. When I unpower the signal, a dropper will fire again if the delay between any two droppers is greater than two ticks. (so if the repeater is set to the second slot or more, it will fire an item when the signal is turned off).

Comment by asdf [ 03/Feb/13 ]

The rules of redstone are very simple when you know them. No other device takes a block update as an input, except piston bud switches, which is also confirmed to be a bug. It also causes more problems than it solves, as redstone that isn't pointing at the dispenser, and in some cases not even next to the dispenser, will set it off.

Comment by Jake [ 02/Feb/13 ]

This bug is OLD and useful, is it really a bug, or just complicated redstone?

Comment by [YT]ZeBests [ 23/Jan/13 ]

screenshot-1.jpg is the bug I'm talking about, not others! Comparators are intended to make constant updates, and dispenser BUD.jpg is acutally not BUD, because the redstone dust is powering the block and that powers the dispenser. I would like to remove the picture but I don't know how and I don't even know if I can.

Comment by Anon Ymus [ 22/Jan/13 ]

This is the same bug.

Comment by Exopandora [ 22/Jan/13 ]

Hey, the Bug I reported isn't the same like that one. You've to wtach the video COMPLETE not the first 10 seconds. The real Bug is that the Dispenser/Dropper is ticking despite the Dispenser/Dropper isn't connected with redstone.

Comment by asdf [ 21/Jan/13 ]

If it were intended, it would have been marked as "Works as intended" as soon as it was confirmed. But no, this report is marked as Confirmed and Unresolved.

Comment by Anon Ymus [ 21/Jan/13 ]

This is a well known bug, but definitely not intended.

Comment by Michael Hubbert [ 21/Jan/13 ]

This is an intended feature of dispensers and droppers.
When they receive a redstone update, as comparators do constantly, the dispenser or dropper will fire repeatedly.

Comment by Phssthpok Pak [ 18/Jan/13 ]

If a comparator is placed facing into a dispenser or dropper and a switch is placed on the side then flipping the switch will make the dispenser/dropper fire continuously. Even though the comparator is un-powered, it seems to cause redstone updates every tick.

Comment by Tails [ 17/Jan/13 ]

Same for the Dropper.

Comment by Benjamin Klingebiel [ 14/Jan/13 ]

This even works when a redstone line two blocks below the dispenser is updated.

Comment by Phssthpok Pak [ 13/Jan/13 ]

An added complication is that, if a comparator is attached to a dispenser filled with non-stacking items (e.g. potions) the comparator output changes each time an item is dispensed, causing a redstone update that triggers the dispenser again. See screen-shot for example set-up.

Comment by Kumasasa [ 28/Nov/12 ]

Thanks for fixing the fix, I intended to set the affected version to 1.4.5, not the fixed version.

Comment by Tails [ 28/Nov/12 ]

Corrected

Comment by asdf [ 28/Nov/12 ]

I believe it's a request to fix version 1.4.5, not a version in which it is fixed. English is a silly language.

Comment by Joël Fivat [ 28/Nov/12 ]

@Kumasasa : Why did you update fix version to "Minecraft 1.4.5" ? Has this been fixed ?

Comment by asdf [ 21/Nov/12 ]

A good fix would be to simply make the dispenser fire as fast as whatever clock you're using can go. It would not only resolve the update bug but also remove the need to use a silly workaround to make the dispenser fire quickly.

Comment by Joël Fivat [ 12/Nov/12 ]

WARNING : this is a well known and useful bug. A lot of people use it to make the dispensers shoot faster. You should check with the community before fixing it.

Google "rapid fire dispenser"
https://www.google.ch/search?q=rapid+fire+dispenser

Comment by Chalmes (Jon) [ 28/Oct/12 ]

Can confirm. Redstone dust placed in positions 1 or 2 will trigger the dispenser, but not on dust removal.

Placing dust in positions 3, 4 or 5 however won't trigger dispenser, but will trigger on removal.

Position 6 has no effect

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