After witnessing behavior of the regeneration logs, its clear that Vanilla
has had bugs with saving duplicate entities for a while....
Some entities are saved in multiple chunks, and now we are bringing those duplicates
out that use to never surface.
This mode will analyze if the entity appears to be a duplicate (near the other dupe uuid)
and delete the entity instead.
This should reduce regenerations to entities that are nowhere near each other, and
therefore more likely to be subject to real UUID collisions due to our
previous bug, and therefor should survive the chunk load.
Vanilla logic checks unload queue and overwrites if its in it.
we're triggering this if a chunk unloads, and reloads immediately in same tick.
Added check for unload queue to not treat as duplicate
Also fixed the config setting not even loading
Should fix#1280
Citizens hijacks entity map, and im guessing under the right conditions
the result might actually be null during entity creation
Pre the cache patch, the id is looked up on save, so it was fine.
Now, if its null and the save ID is requested, we will try to look
it up again and cache it if found.
Due to a bug in 2e29af3df0
which was added all the way back in March of 2016, it was unknown (potentially not at the time)
that an entity might actually change the seed of the random object.
At some point, EntitySquid did start setting the seed. Due to this shared random, this caused
every entity to use a Random object with a predictable seed.
This has caused entities to potentially generate with the same UUID....
Over the years, servers have had entities disappear, but no sign of trouble
because CraftBukkit removed the log lines indicating that something was wrong.
We have fixed the root issue causing duplicate UUID's, however we now have chunk
files full of entities that have the same UUID as another entity!
When these chunks load, the 2nd entity will not be added to the world correctly.
If that chunk loads in a different order in the future, then it will reverse and the
missing one is now the one added to the world and not the other. This results in very
inconsistent entity behavior.
This change allows you to recover any duplicate entity by generating a new UUID for it.
This also lets you delete them instead if you don't want to risk having new entities added to
the world that you previously did not see.
But for those who are ok with leaving this inconsistent behavior, you may use WARN or NOTHING options.
It is recommended you regenerate the entities, as these were legit entities, and deserve your love.
Aikar