Support for snapshot 21w43a (Minecraft 1.18)

[ghost]

Hello ! ^^
In the 1.18 snapshot 21w43a, the Level tag doesn't exist anymore.
It means that for region chunks (Not entities or POI), data is now stored at the root of the chunk.
Changes in the code :

• Detect chunk type with a central function (get_chunk_type()).
• Adjustements on REGION chunks which do not have the Level tag.
• Fix entities deletion in 1.17 entities chunks and 1.18 level chunks (Which shouldn't happen).

Wiki : https://minecraft.fandom.com/wiki/Java_Edition_21w43a

Important note : I use the tag DataVersion, which I think is the best thing to do.
I don't know if Mojang will make other changes, but just in case, please do not merge this PR yet, I think it's better to wait.
Have a nice day ! ^^

[Fenixin]

Thank you!

I'll try to look into this the following days but I'm in a busy week.

[ghost]

Update : 1.18 pre-release 1 is out today, no other changes to report. Yay !
https://minecraft.fandom.com/wiki/Java_Edition_1.18_Pre-release_1

[ghost]

Update 1.18 will be released tomorrow, and there is no other change to world storage. Yay ! ^^
https://minecraft.fandom.com/wiki/Java_Edition_1.18#General_2

If you have some time, you can test this PR, and merge it if it's okay for you.

[Fenixin]

Again, thank you for keeping track of the changes, I'll review this soon. I can review the code and test with the worlds I have around in a few days (this weekend if the week keeps being so busy).

[ghost]

You're welcome. Take your time for testing ! ^^

[prenetic]

Trying this out with a 1.5 world that was migrated forward through each major Minecraft version to 1.18 and I'm running into the following exception, not sure if this is relevant but noticed it's from get_chunk_type(). Happy to provide a copy of the world if necessary.

--------- Scanning region, POI and entities files ----------
Scanned region\r.-1.-1.mca (c:0, w:0, tme:0, so:0, mt:0, t:1024)...... 1/507
Scanned region\r.-1.-10.mca (c:0, w:0, tme:0, so:0, mt:0, t:0)......... 2/507
Scanned region\r.-1.-2.mca (c:0, w:0, tme:0, so:0, mt:0, t:1024)...... 3/507
Scanned region\r.-1.-3.mca (c:0, w:0, tme:0, so:0, mt:0, t:1024)...... 4/507
Scanned region\r.-1.-4.mca (c:0, w:0, tme:0, so:0, mt:0, t:1024)...... 5/507
Scanned region\r.-1.-5.mca (c:0, w:0, tme:0, so:0, mt:0, t:1024)...... 6/507
Scanned region\r.-1.-6.mca (c:0, w:0, tme:0, so:0, mt:0, t:1012)...... 7/507


Ops! Something went really wrong and regionfixer crashed.


Bug report:

**********
*** Exception while scanning:
*** r.-1.-7.mca
**********
*** Printing the child's traceback:
*** Exception:<class 'AssertionError'>Unrecognized chunk type in get_chunk_type().
**********
*** File E:\Source\Repos\Minecraft-Region-Fixer\regionfixer_core\scan.py, line 810, in scan_region_file
***   chunk, tup = scan_chunk(region_file,**********
*** File E:\Source\Repos\Minecraft-Region-Fixer\regionfixer_core\scan.py, line 913, in scan_chunk
***   chunk_type = world.get_chunk_type(chunk)**********
*** File E:\Source\Repos\Minecraft-Region-Fixer\regionfixer_core\world.py, line 1847, in get_chunk_type
***   raise AssertionError("Unrecognized chunk type in get_chunk_type().")
**********

[ghost]

Hello @prenetic ! ^^
Thank you for your test.
This is strange. Does a similar error happens with the current version ? You should see the following exception :

AssertionError("Unrecognized scanned chunk in scan_chunk().")

Because get_chunk_type() works the same as the chunk type detection in scan_chunk().
By the way, I would be glad if you could give me a copy of the world ? Or just the region\r.-1.-6.mca file.
Have a nice day !

[prenetic]

Yes that's correct, I receive AssertionError("Unrecognized scanned chunk in scan_chunk().") with the current version. I've attached both r.-1.-6.mca and r.-1.-7.mca since the exception seems to indicate an issue scanning the latter. Perhaps this is a different 1.18 compatibility issue.

region.zip

[ghost]

Thank you for those files. If I'm correct, this is an 1.18 world ?
Did you create it with 1.18, or is it an updated world ?

[ghost]

@prenetic It should be fixed now. ^^
Thank you very much for your tests ! :D

[prenetic]

Thank you for those files. If I'm correct, this is an 1.18 world ? Did you create it with 1.18, or is it an updated world ?

This is a VERY old world, I don't know exactly how old, but it was created pre-Anvil. I upgraded through every major release since then, and is currently a loaded as a 1.18 world.

I'll give your latest update another shot in the morning (it's late here), but if you don't hear back then no news is good news. :)

[prenetic]

Grabbed the latest and gave it another shot (through 3f3fcb1). Just to confirm, this does seem to be an issue with the world converted to 1.18. I pulled down a copy of the world from back when it was still 1.5 and the scans go through just fine. I don't have a copy of any intermediate conversions between the two versions for testing. Below is the latest exception and offending region file.

r.-1.0.mca.zip

--------- Scanning region, POI and entities files ----------
9 of 507|                                                        |ETA:  0:15:36

Ops! Something went really wrong and regionfixer crashed.


Bug report:

**********
*** Exception while scanning:
*** r.-1.0.mca
**********
*** Printing the child's traceback:
*** Exception:<class 'AssertionError'>Unrecognized chunk type in get_chunk_type().
**********
*** File E:\Source\Repos\Minecraft-Region-Fixer\regionfixer_core\scan.py, line 810, in scan_region_file
***   chunk, tup = scan_chunk(region_file,**********
*** File E:\Source\Repos\Minecraft-Region-Fixer\regionfixer_core\scan.py, line 913, in scan_chunk
***   chunk_type = world.get_chunk_type(chunk)**********
*** File E:\Source\Repos\Minecraft-Region-Fixer\regionfixer_core\world.py, line 1856, in get_chunk_type
***   raise AssertionError("Unrecognized chunk type in get_chunk_type().")
**********

[ghost]

Thank you for this new test.
The same problem is occurring : The tag that I use to tell that this is a region chunk (And not entities or POI) doesn't exists.
So, sections isn't mandatory, nor TerrainPopulated...
This is strange. I don't know if it's a Minecraft bug, or if it's normal, and there is no documentation.

[ghost]

@prenetic Here is another try : dd44ce4

[Fenixin]

Hello! I'll dive into this and try to help this weekend. @734F96, thanks!!

[ghost]

@Fenixin You're welcome. ^^
Also, I took the liberty to answer to issues about 1.18 support (#170, #171, #172 and #173).

[prenetic]

@prenetic Here is another try : dd44ce4

Looks like that may have done the trick! I successfully scanned all of the migrated worlds that were leading to issues (overworld, nether, and end dimensions). :)

[ghost]

Thanks for the confirmation @prenetic ! :D
I merged my commits into one to make it easier for @Fenixin. ^^

[Fenixin]

Merged! Thank you!

[Fenixin]

I want to do a few more test with old and broken worlds, but I have delayed this enough.

[ghost]

Hello ! You're welcome @Fenixin ! ^^
It's a always a good idea to make more tests. If you find some errors, you can report them to me and I will try to fix them. ;)

[ghost]

@Fenixin
https://github.com/Fenixin/Minecraft-Region-Fixer/releases/tag/v0.3.5
"if you are using this version you should thank him!"
Thanks for the mention, but it's "her". ^^

[Fenixin]

Ups! I'm really sorry! I've just fixed it!

[ghost]

@Fenixin No problem, thanks for the fix. :D
Have a nice evening ! ^^