this should produce some reduction in spam at the source.
This could also be used to control the rate at which constantly-crashing servers restart to stop them spamming the disk as well, but the main concern here is eliminating crash archive involuntary DDoS by crashy servers.
This supersedes addChunkPacket() in most cases, and has a more clear name. It broadcasts the given packet to every player who has the target position within their chunk load radius.
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 can happen when eval() is used, and then we get a big blank mess with nothing on it. eval() is a special case that should be handled separately, but for now this is just fixing a bug.
This was observed in a recent crashdump where a plugin triggered a recursion error, but the stack trace did not contain any sign of a recursive event call. I conclude that this must have been caused by previous event handlers triggering errors 50 times in order to make the recursion detection break, because the recursion detection did not decrement the counter in cases where an exception was thrown.
while we can't deal with this information, it's needed for the sake of unit testing so we don't shit on every bit of incoming data of these packet types.