fixes#2295
There is still an issue in that the spawn point will not be offset if the chunk is not generated, but this is better than the spawn point being down at y=0. The other issue is a job for another time.
This is quite an interesting bug. If you have
```php
class A{
public function onMove(PlayerMoveEvent $event){} //shouldn't be a handler because this class isn't a Listener
}
class B extends A implements Listener{}
```
then
```php
registerEvents(new B, $plugin);
```
then `A::onMove()` will be registered as an event handler even though `A` is not an instanceof `Listener`.
This was observed by noting that plugins which do something like `extends PluginBase implements Listener` causes `registerEvents()` to try and register `PluginBase` methods as event handlers, which could lead to astonishing behaviour.
then A::onMove() will be registered as an event handler even though A is not an instanceof Listener.
This was observed by noting that plugins which do something like "extends PluginBase implements Listener" causes registerEvents() to try and register PluginBase methods as event handlers, which could lead to astonishing behaviour.
this fixes a potential exploit where clients could append JWTs signed with their own keys to the end of the chain containing fake XUID/UUID/username which would then overwrite the legitimate ones in earlier links.
This stems from the fact that the final link of the vanilla chain contains the client's own pubkey, so the client is able to append its own data to the end of the chain.
I considered making this instead save the default config instead of creating an empty config file, but that would be (albeit minor) a behavioural change which therefore belongs in 3.1.
If there is an empty list of blocks in the changedBlocks array for a chunk, that means that blocks changed the normal way and then were later set the direct way in the same tick. This means that no action needs to be taken on these chunks.
onGround doesn't necessarily reflect 0 motion, because something else could change the motion prior to the onGround flag getting updated - for example 2 knockbacks in a row.
This can happen when an attacker attacks a victim wearing thorns armour while having low health, which prior to this commit would cause the tool to be duplicated.
this has already been seen to cause duplication bugs when thorns is used. Anything else that modifies inventory during applyPostDamageEffects() when the mob is possibly dead will also cause duplication issues.
they got removed from the tasks array, but not from the queue (for performance reasons). The queue gets cleaned up by the heartbeat, but it was checking if there were things in the main array, not in the queue.
There are a couple of other bugs with cancelling tasks that this doesn't fix that are rather more complicated to deal with.
