Lava / water / powder snow bucket desync when using it while rapidly turning

I hope somebody will response! 😃 🙂

This is an old bug and does not actually relate to doors.
Occasionally lava source blocks do not fill buckets correctly (serverside) and minecraft restates the faulty bucket (clientside) in your inventory as empty when you happen to update its item. If the item is in your hand it restates immediately after you use it (right click) even if you actually use something else like a door. Because you cannot stack full buckets, they also appear full in your inventory when (pseudo)filled. In this case your bucket will be restated when you try to move it in inventory.

Guide to reproduce:
1. Take 10-20 empty buckets to the lava source.
2. Quickly use them to drain as much source blocks as you can reach.
3. Try to move your lava buckets within your inventory or use them in any way. There is a chance some of them would reappear empty. Repeat if necessary.

Alright! 🙂
Thank you for your reply!

Is this still a concern in the latest Minecraft version 14w30c? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

Probably fixed. Spent 4 stacks of buckets in survival to drain a small lake - no bucket was considered empty by the game.

This just happened to me today on the latest snapshot 15w35e - was quite happily filling buckets of lava from a deep underground pool got to the surface to find the bucket was empty when I tried to placer it in a chest, had been carrying it in my hand on the way up not in my inventory. Happened after 7 buckets of lava had been transported.

I can still reproduce this in SSP in 15w46a. A single bucket and a single lava source is enough; I just walked around constantly placing and the picking up the lava. After a minute, I ended up with a full bucket, but also lava flowing in front of me. Moving the bucket in my inventory cause the bucket to magically 'empty'. Simple client-server mismatch.

It sounds like possibly MC-94008 has some simple repro steps to reproduce this bug with milk, though I've not confirmed it.

MC-95720 has some useful demo/repro of possible de-sync conditions

Made a quick video https://www.youtube.com/watch?v=GiCs20Rcn9Q

Can also be abused on servers https://www.youtube.com/watch?v=TMJefiUYleI

I can confirm that this issue is still occurring sporadically, playing on Minecraft 1.10.2. Yesterday I was able to carry lava around in buckets just fine, but for some reason when I tried to do it today I encountered this issue where I would fill the bucket with lava, and then I would walk a little ways and look down and see that the bucket is empty.

Can someone tell me reproduction steps with lava or water for the current snapshot version?
I tried several tests, but couldn't manage to reproduce it so far with lava or water. Someone said (in 2015) it seemed to occur more frequently with high ping, which messes badly in PvP of course, if this is still the case.

I only could reproduce it in 17w16b with milk (MC-107103) as demonstrated in MC-94008.

(Offer to overtake this bugpost for more frequent updating, in case it still occurs with water/lava in the newest snapshot.)

Here you go, did the same thing I did a year ago (but now on the latest snapshot ofc). The second test (placing water) behaved a bit different this time around. This is all on singleplayer, once again the higher your ping to a server, the more often this happens.

Is this still an issue in the most recent versions (currently that is 1.12.2, or 18w02a) of Minecraft? If so, please update the affected versions and help us keeping this ticket updated from time to time. If you are the owner/reporter of this ticket, you can modify the affected version(s) yourself.

I am the Reporter, yes. I don't really play the game anymore so I can't tell, if it is still an issue or not.

If it's possible I give anyone the right who is currently active to modify the version. 🙂

This is trivial to reproduce:

Give yourself a lava bucket. As you spin around (move mouse) standing on a flat plain, repeatedly try to put down and pick up the lava in the bucket. About 1 in 10 times, the client and server desync (e.g. I see the lava on the ground, and also in my bucket, until I use the bucket again or move it in my inventory; or I see no lava on the ground and my inventory displays the bucket as empty, but I actually still have lava and can place it).

(I just reproduced in in 18w02a)

Gave the report to @unknown.

Happened to me with water as well, therefore I am going to change the report.

Confirmed for 18w20c

@unknown, please write new comments (and delete your old ones if you want to keep the comment section clean) instead of just editing your latest comment. If you edit a comment, that's only visible to users that are watching the report, and doesn't appear in the activity feed.

Thank you, I did'nt know that

Confirmed for 1.13-pre2

Confirmed for 1.13-pre3

Confirmed for 1.13-pre9

@@unknown, thank you very much, but there is no need to provide screenshots or gifs every time you confirm this bug. The now attached examples should be enough.

@Marcono1234 Oh okay! Sorry

And also... Confirmed for 1.13-pre10!

Just a question : why no manager is still associated with this bug report?

Because this bug isn't being worked on right now.

Still in 18w30b

Still in 18w31a

Still in 18w32a

Still in 18w33a

Still in 1.13.1-pre1

Still in 1.13.1 release

Ghost water blocks are still a thing in 1.13.1

Still in 1.13.2-pre1

Still in 1.13.2-pre2

Still in 18w43b

Why is there still a fixed version for a bug that was reopened ? Also, it can happen in creative too (not only in gamemode survival)

Still in 19w05a

Still in 19w06a

Still in 19w07a

Still in 19w08a

Still in 19w09a

Still in 19w11a

Still in 19w11b

Still in 19w12b

Still in 19w13a

Still in 19w14a

Still in 1.14 Pre-Release 1

Still in 1.14 Pre-Release 2

Still in 1.14 pre-3 and 1.14 pre-4

Still in 1.14 pre-5

Still in 1.14 Release

Still in 1.14.1 Release

Still in 1.14.2 Pre-Release 1 and 1.14.2 Pre-Release 2

Still in 19w36a

Relates to MC-9591

Affects 20w12a

Also affects multiplayer from my experience.

Affects 1.16 pre-release 5

Affects 1.16.2 snapshot 20w28a

Can't imagine this has never been reported, almost positive this is a duplicate.

This is the original report? It was created in 2013

The eternal bug

Just replicated this bug in the latest version (1.16.3). Saving and exiting the world then relaunching it fixes the holes in the water. With this you can theoritically make an empty pool on nothing and have a player drown in the air.

Also affects powder snow buckets, see MC-205225

Confirmed in 20w46a

Confirmed in 20w51a

I wonder if they will ever fix this, it is marked as important and should be a simple fix

Try making the max speed of picking up water less.

I feel like this is from the bucket picking up two blocks of water/lava simultaneously then not filling in the gap that's left over, making the speed of picking up water less would still cause the bug but just less frequently

Can confirm in 21w07a.

Can confirm in 21w08b.

I'd like to request ownership of this ticket since the reporter has been inactive since February 2018. I'm willing to keep this ticket updated and provided all of the necessary information.

It is not fully fixed in 21w11a, but it seems harder to reproduce now.

@unknown Thanks for testing! Impressive how fast you managed to break it 😉
I was able to reproduce what you showed, though it turns out to be a different issue with a similar effect.
This report is about the desync when rapidly turning the camera (because the position and rotation server and client would simulate the right click action with could be mismatched), the other version you found happens when picking up two liquid blocks that are behind each other in close succession. It can be reproduced by having two water blocks with empty space behind them and then clicking two times with an empty bucket with roughly 250ms delay in between.

This issue warrants a new report.

New report is MC-219875

@panda4994 Why exactly are liquids calculated server-side? It would be much simpler to calculate it client-side and have the server validate it, just like the rest off the blocks. 

@unknown Yes, you are absolutely right, it should work like this. However it's not a simple change to do at the moment, as it has implications for how the offhand is handled, and the resulting changes have implications for modded servers.
The current fix is a small patch to avoid the most annoying part of the issue from showing up.

I can confirm this happening on 1.16.5. In vanilla survival on a vanilla server.

Scenarios that can happen (from experience) that can be related to this:
1. 

2. Your water bucket looks full with water, but when you try to place it, your water disappears.

This issue has been fixed in the 1.17 snapshots, and should be released alongside Caves and Cliffs: Part 1 on June 8th (in a little less than two days).

Not fixed, Reproduced in 1.17

Are you experiencing MC-219875?

This bug is not possible to fix — it is a knowledge problem between the server and client. There will always be a chance of desynchronization due to simple physics, and packet loss is a reality. Attempts at fixing it have only caused more issues for plugin developers, who then have to deal with filtering duplicate packets.