[MC-45552] Item frames duplicate on (re)loading

After the snapshot update, the server shuts down reproducibly when a player enters a nether portal. The server log looks normal, and from client side it looks just like the server was shut down normally.

L3viathan delivered reproducibility instructions:

How to reproduce:
1. Create new world
2. Enter Nether
3. Attach Item Frame to block
4. Put Item into Item Frame
5. Leave Nether
6. Reenter Nether
P.S.: This can also be used to dupe items: Place an item in the item frame and break the chest.
P.P.S.: It might have nothing to do with the chests, just with the item frames

Attachments

latest.log

Comments 21

galaxy_2alex 2014-01-23T17:44:47Z

"which I should probably report, too."
Yes, I agree.

Jemus42 2014-01-23T17:51:04Z

Reported the no logfile bug thing

EDIT: …The log thing was fixed by redownloading the .jar, will now try to get to the issue at hand.

Jemus42 2014-01-23T18:18:36Z

I attached the message the player sees after entering the nether portal, comes directly after the "Downloading terrain" screen.
Server seems to shut down as normal as soon as the nether should be loaded.

The server log does not contain any error messages, from the log it looks like a normal shutdown.

DaMaloma 2014-01-23T18:27:09Z

Can confirm this happens on my server too after the redownload. But it only happens on my ordinary world that has been around since late snapshot phase for 1.7. A new fresh world doesn't make it happen.

Jemus42 2014-01-23T18:32:40Z

Well, our world is over a year old, definitely everything but fresh.

11 more comments

Nathan Adams 2014-01-24T08:47:23Z

Can't reproduce. Can you possibly upload the world?

DaMaloma 2014-01-24T09:09:31Z

I opened the world in sp today and managed to go to the nether. It took some time for it to work so I was sure I would crash. Attached is a screenshot of what was there. There are so many pigmen it is a miracle I could do anything at all. I tried killing them with /kill @e[type=PigZombie] but it didn't work, they were totally unaffected. Something is wrong with pigmen spawning and dying it seems.

DaMaloma 2014-01-24T09:14:14Z

I would be happy to upload my world. It is 1,61GB big though...

Jemus42 2014-01-24T09:35:36Z

I uploaded the world here: http://dump.quantenbrot.de/wurstmineberg_2014-01-24_08h00.tar.gz

Disclaimer: It's 1.9 GB, and uncompressed it's 3 GB.

Bob Saggot 2014-01-24T09:40:34Z

Make a copy of your world, open it with MCEdit, switch to The Nether and delete all the chunks in let's say radius of 10 chunks from those containing pigmen, then save the world. Your save file should be good to upload then, but I'm not sure if it won't affect the bug iself.

Jemus42 2014-01-24T09:43:16Z

Regarding getting rid of the pigmen: Maybe it's easier to shut down the server, switch to peaceful/difficulty 0 in the server properties, and start the server again? Of course this would "delete" every hostile mob, which may not be a desired result, bit it's probably better than having no nether.

DaMaloma 2014-01-24T09:50:32Z

I don't see what deleting the pigmen has to do with uploading the file for Mojang to inspect the reason for them being there and crashing the world. I can of course delete them in MCEdit and try using the world, hoping they won't return. But if the bug is still there when 1.8 is released then there will be a lot of server owners with old worlds going nuts over the infestation and crashes...

As for uploading the world for inspection by Mojang I have no idea of where to put it since I am not accustomed to uploading huge files to the net. I am happy that Jemus has uploaded his now and hope that will suffice.

Jemus42 2014-01-24T13:01:29Z

So I'm back home now and downloaded our server world from the link I provided (so it's the same version of the backup), and I entered the nether, where I landed way below our nether hub/portals which are around y110.
Anyway: There are >3200 entities, which is way too many and probably enough to force our server to shutdown, my laptop can barely handle it as it is.

Then I did /kill @e[type=PigZombie], which had close to no effect.
Then I killed all Ghasts, which only resultet in one Ghast being killed, so there's that.
Then I killed all item entities, which didn't help much.
Then I killed all the chicken, which yielded errors, but still too many entities.
… In total, I Killed Zombie Pigmen, Chicken, item entities, Ghasts, Skeletons, Magmacubes, but I still see >3100 entities.

In the end, I used F3 too look for where exactly these entities are, and it seemed to be our chests in the hub where materials for the hub construction/tunnels are stored. After I broke each chest, the total entitiy count did not rise dramatically as expected, but stayed the same. I then used the command to kill item entities after the chest was broken to remove all the items, and then the entitiy count dropped. After I broke all the chests and killed all the items, entitiy count is back to normal.

See final screenshot

Jemus42 2014-01-24T13:16:57Z

More insights!

I deleted the world and unzipped the backup again to try something else: Breaking the item frames attached to the chests, some of them containing blocks, which were rendered weirdly as of the other bug I don't have at hand now, but it's known and appears in the snapshot videos of docm77 and SethBling afair. Anyway, I couldn't break the item frames on the chests, but after I broke the chests (and the item frames with it, obviously), it got better.

I made a screen recording so you can take a look at it, but it's still uploading, will edit this comment.

EDIT:
~~Here's the screen recording, relevant part @ 2min~~
Nevermind, L3viathan's video and reproduction steps are way better.

L3viathan 2014-01-24T13:18:55Z

How to reproduce:

1. Create new world
2. Enter Nether
3. Attach Item Frame to block
4. Put Item into Item Frame
5. Leave Nether
6. Reenter Nether

P.S.: This can also be used to dupe items: Place an item in the item frame and break the block it is attached to.

Jemus42 2014-01-24T13:27:31Z

I attached the latest client log file from my experiment with the world. Has lots of errory looking things.

@l3viathan: So… We basically have a missingno way to dupe items now? That brings back so many memories 🙂

L3viathan 2014-01-24T13:49:11Z

I made a short video demonstrating the bug (and the duping). Note the high entity count:

http://www.youtube.com/watch?v=U_8S18O-ic4

odoto 2014-01-24T13:54:07Z

so the frames create a huge amount of entities both of frames and the item type? that should help a lot with the fixing 🙂

DaMaloma 2014-01-24T14:25:26Z

Can confirm that is has to do with item frames. I could reproduce in two of three worlds. In one the item count went up with only item frames with an item in. By the fifht item frame the zombie pigmen started pouring down a slope next to the portal. On the other I had one item frame on a chest and about eight item frames on blocks, all with items inside, before it became unplayable with over 8000 entities. On the third one nothing at all happened when I placed the item frames with items in, which makes the whole thing a bit confuddling still.

Jemus42 2014-01-24T14:34:48Z

Apparently it's not as easy to reproduce as we thought, it doesn't happen on all worlds.
So here's the seed for our server's world: -6720233900416869526

Howard Chen 2014-05-26T18:19:00Z

Our server ran into the same problem, I think it has to do with the itemframe being in different chunks than the chest