1) Sign loading code was trying to parse the JSON before the check for oldSign.
That code could then skip the old sign converting code if it triggers a JSON parse exception.
2) New Mojang Schematic system has Tile Entities in the new converted format, but missing the Bukkit.isConverted flag
This causes Igloos and such to render broken signs. We fix this by ignoring sign conversion for Defined Structures
Vanilla will double add Spider Jockeys to the world, so ignore already added.
Also add debug if something else tries to, and abort before world gets bad state
Some pretty micro optimizations, but this is the hottest method in the server....
This will drastically reduce number of operations to perform getType
the 2 previous patches was squashed into 1
When players are moving in the world, doing things such as building or exploring,
they will commonly go back and forth in a small area. This causes a ton of chunk load
and unload activity on the edge chunks of their view distance.
A simple back and forth movement in 6 blocks could spam a chunk to thrash a
loading and unload cycle over and over again.
This is very wasteful. This system introduces a delay of inactivity on a chunk
before it actually unloads, which is maintained separately from ChunkGC.
This allows servers with smaller worlds who do less long distance exploring to stop
wasting cpu cycles on saving/unloading/reloading chunks repeatedly.
Crystals can end up in a bad state in certain conditions which causes
an exception on the expected number of crystals going negative.
This ensures the crystals/pillars are in expected state when the dragon spawns.
See #3522
On servers with plugins that constantly churn through scoreboards, there is a risk of
degraded GC performance due to the number of scoreboards held on by weak references.
Most plugins don't even need the (vanilla) functionality that requires all plugin
scoreboards to be tracked by the server. Instead, only track scoreboards when an
objective is added with a non-dummy criteria.
This is a breaking change, however the change is a much more sensible default. In case
this breaks your workflow you can always force all scoreboards to be tracked with
settings.track-plugin-scoreboards in paper.yml.
