Memory leak if BukkitPermissionAttachmentManager.getOrAddAttachment called for player that is offline

[MsMaciek123]

Server Implementation

Paper

Server Version

1.21.4

Describe the bug

getOrAddAttachment shouldn't add attachment to attachments hashmap if player is offline, because otherwise it leaks memory.

FastAsyncWorldEdit/worldedit-bukkit/src/main/java/com/fastasyncworldedit/bukkit/BukkitPermissionAttachmentManager.java

Line 22 in f137a11

public PermissionAttachment getOrAddAttachment(@Nullable final Player p) {

This bug happens in WorldGuard, https://github.com/EngineHub/WorldGuard/blob/ab48a6623722ac8ce34172eed13b8319444a61da/worldguard-bukkit/src/main/java/com/sk89q/worldguard/bukkit/listener/WorldGuardPlayerListener.java#L158
where recipient can possibly be a player instance that is offline. This happens because AsyncPlayerChatEvent could be delayed and later executed with player that is offline (see PaperMC discord, https://discord.com/channels/289587909051416579/555462289851940864/1365615050429304955)

I've attached stacktrace where it happens.

To Reproduce

Register onPlayerQuit event, call getOrAddAttachment after few seconds for the player that left. The player will stay in hashmap forever leaking memory.

Expected behaviour

Don't save player in hashmap if is offline

Screenshots / Videos

No response

Error log (if applicable)

https://gist.github.com/MsMaciek123/e56f5548f391b0fb0ce85fdeeaeebab4

Fawe Debugpaste

n/a

Fawe Version

FastAsyncWorldEdit version 2.13.1-SNAPSHOT

Checklist

• I have included a Fawe debugpaste.
• I am using the newest build from https://ci.athion.net/job/FastAsyncWorldEdit/ and the issue still persists.

Anything else?

FAWE doesn't seem to ever be calling getOrAddAttachment for player that is offline, and I was unsure whether to report it to FAWE or WG, but was told to report it here.

[MsMaciek123]

Fixed with PR #3182