this process of fast-serialization, fast-deserialize, network-serialize is an order of magnitude slower than just doing the network encode directly on the main thread, and also copies more useless data.
For the main thread, the figures were something like 3x more expensive, and then an extra 7x for deserialization on the worker thread. This is a ridiculously large overhead.
This can happen when a light source is removed and later encountering another light source to fill the gap. A higher light level may get set and then not propagated. This bug is difficult to explain, but fairly easy to reproduce.
Grass can cause issues here by requesting blocks randomly offset away from itself, which can cause silent chunk loading on chunk ticking. It also causes crashes if chunk autoloading is taken away, which is obviously undesired.
It was also noticed that player chunkloaders cause chunks to start getting ticked as soon as they load their first chunk, which is before the entity is visible to everyone else on the server. This is probably undesired behaviour.
This assumes that the region is properly garbage-collected and packed, but if the file contains uncollected garbage this may not be the case, resulting in a region larger than a gigabyte.
PhpStorm can't see constructor usages when the class name is dynamic. This causes maintenance problems because cross-referencing constructors called like this doesn't show up dynamic calls.
Previously any random error could occur during an AsyncTask preparing a chunk, and the Level would never know about it and thus never send the chunk.
I don't know how many invisible-chunk bug cases this fixes, but I expect it's quite a lot.
I don't care if this matches PC behaviour or not. bugs.mojang.com is full of bug reports about this. Just search for "minecraft spawn protection not working" and you'll see what I mean.
If you want to disable spawn protection, actually disable it. This behaviour is something that most users are not aware of and find astonishing when they discover it.
This behaviour was copied from Minecraft PC, and it's nearly as unexpected there as it is here.
This commit reverses the stupidity done in eb0525e892.
