Upstream has released updates that appear to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing
Bukkit Changes:
82af5dc6 SPIGOT-7396: Add PlayerSignOpenEvent
3f0281ca SPIGOT-7063, PR-763: Add DragonBattle#initiateRespawn with custom EnderCrystals
f83c8df4 PR-873: Add PlayerRecipeBookClickEvent
14560d39 SPIGOT-7435: Add TeleportCause#EXIT_BED
2cc6db92 SPIGOT-7422, PR-887: Add API to set sherds on decorated pots
36022f02 PR-883: Add ItemFactory#getSpawnEgg
12eb5c46 PR-881: Update Scoreboard Javadocs, remove explicit exception throwing
f6d8d44a PR-882: Add modern time API methods to ban API
21a7b710 Upgrade some Maven plugins to reduce warnings
11fd1225 PR-886: Deprecate the SmithingRecipe constructor as it now does nothing
dbd1761d SPIGOT-7406: Improve documentation for getDragonBattle
CraftBukkit Changes:
d548daac2 SPIGOT-7446: BlockState#update not updating a spawner's type to null
70e0bc050 SPIGOT-7447: Fix --forceUpgrade
6752f1d63 SPIGOT-7396: Add PlayerSignOpenEvent
847b4cad5 SPIGOT-7063, PR-1071: Add DragonBattle#initiateRespawn with custom EnderCrystals
c335a555f PR-1212: Add PlayerRecipeBookClickEvent
4be756ecb SPIGOT-7445: Fix opening smithing inventory
db70bd6ed SPIGOT-7441: Fix issue placing certain items in creative/op
f7fa6d993 SPIGOT-7435: Add TeleportCause#EXIT_BED
b435e8e8d SPIGOT-7349: Player#setDisplayName not working when message/format unmodified
a2fafdd1d PR-1232: Re-add fix for player rotation
7cf863de1 PR-1233: Remove some old MC bug fixes now fixed in vanilla
08ec344ad Fix ChunkGenerator#generateCaves never being called
5daeb502a SPIGOT-7422, PR-1228: Add API to set sherds on decorated pots
52faa6b32 PR-1224: Add ItemFactory#getSpawnEgg
01cae71b7 SPIGOT-7429: Fix LEFT_CLICK_AIR not working for passable entities and spectators
a94277a18 PR-1223: Remove non-existent scoreboard display name/prefix/suffix limits
36b107660 PR-1225: Add modern time API methods to ban API
59ead25bc Upgrade some Maven plugins to reduce warnings
202fc5c4e Increase outdated build delay
ce545de57 SPIGOT-7398: TextDisplay#setInterpolationDuration incorrectly updates the line width
Spigot Changes:
b41c46db Rebuild patches
3374045a SPIGOT-7431: Fix EntityMountEvent returning opposite entities
0ca4eb66 Rebuild patches
Patch documentation to come
Issues with the old system that are fixed now:
- World generation does not scale with cpu cores effectively.
- Relies on the main thread for scheduling and maintaining chunk state, dropping chunk load/generate rates at lower tps.
- Unreliable prioritisation of chunk gen/load calls that block the main thread.
- Shutdown logic is utterly unreliable, as it has to wait for all chunks to unload - is it guaranteed that the chunk system is in a state on shutdown that it can reliably do this? Watchdog shutdown also typically failed due to thread checks, which is now resolved.
- Saving of data is not unified (i.e can save chunk data without saving entity data, poses problems for desync if shutdown is really abnormal.
- Entities are not loaded with chunks. This caused quite a bit of headache for Chunk#getEntities API, but now the new chunk system loads entities with chunks so that they are ready whenever the chunk loads in. Effectively brings the behavior back to 1.16 era, but still storing entities in their own separate regionfiles.
The above list is not complete. The patch documentation will complete it.
New chunk system hard relies on starlight and dataconverter, and most importantly the new concurrent utilities in ConcurrentUtil.
Some of the old async chunk i/o interface (i.e the old file io thread reroutes _some_ calls to the new file io thread) is kept for plugin compat reasons. It will be removed in the next major version of minecraft.
The old legacy chunk system patches have been moved to the removed folder in case we need them again.