Paper/Spigot-Server-Patches/0429-Ensure-Entity-is-never-double-registered.patch
Spottedleaf dafc7b8f8d
Fix off by one error for scheduling block ticks (#4014)
Co-authored-by: Spottedleaf <Spottedleaf@users.noreply.github.com>

Fixes #4015
2020-07-28 01:19:11 -04:00

80 lines
3.7 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 29 Mar 2020 18:26:14 -0400
Subject: [PATCH] Ensure Entity is never double registered
If something calls register twice, and the world is ticking, it could be
enqueued to add twice.
Vs behavior of non ticking of just overwriting state.
We will now simply log a warning when this happens instead of crashing the server.
diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index c49d157b8ca25f9811bf64396c207b1c1d6e085d..e895bf811ce5d441541725ade48e3f07ca86fc2b 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -59,6 +59,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
}
// Paper start
+ boolean isQueuedForRegister = false;
public static Random SHARED_RANDOM = new Random() {
private boolean locked = false;
@Override
diff --git a/src/main/java/net/minecraft/server/WorldServer.java b/src/main/java/net/minecraft/server/WorldServer.java
index eebd453bfaeb99b8fdf0d11ee8888f27ad2afff2..0e28e829474bea693550b3b2f0e72f97ff9bb10e 100644
--- a/src/main/java/net/minecraft/server/WorldServer.java
+++ b/src/main/java/net/minecraft/server/WorldServer.java
@@ -530,6 +530,7 @@ public class WorldServer extends World implements GeneratorAccessSeed {
Entity entity2;
while ((entity2 = (Entity) this.entitiesToAdd.poll()) != null) {
+ if (!entity2.isQueuedForRegister) continue; // Paper - ignore cancelled registers
this.registerEntity(entity2);
}
@@ -1228,6 +1229,19 @@ public class WorldServer extends World implements GeneratorAccessSeed {
public void unregisterEntity(Entity entity) {
org.spigotmc.AsyncCatcher.catchOp("entity unregister"); // Spigot
+ // Paper start - fix entity registration issues
+ if (entity instanceof EntityComplexPart) {
+ // Usually this is a no-op for complex parts, and ID's should be removed, but go ahead and remove it anyways
+ // Dragon parts are handled special in register. they don't receive a valid = true or register by UUID etc.
+ this.entitiesById.remove(entity.getId(), entity);
+ return;
+ }
+ if (!entity.valid) {
+ // Someone called remove before we ever got added, cancel the add.
+ entity.isQueuedForRegister = false;
+ return;
+ }
+ // Paper end
// Spigot start
if ( entity instanceof EntityHuman )
{
@@ -1294,9 +1308,21 @@ public class WorldServer extends World implements GeneratorAccessSeed {
private void registerEntity(Entity entity) {
org.spigotmc.AsyncCatcher.catchOp("entity register"); // Spigot
+ // Paper start - don't double enqueue entity registration
+ //noinspection ObjectEquality
+ if (this.entitiesById.get(entity.getId()) == entity) {
+ LOGGER.error(entity + " was already registered!");
+ new Throwable().printStackTrace();
+ return;
+ }
+ // Paper end
if (this.tickingEntities) {
- this.entitiesToAdd.add(entity);
+ if (!entity.isQueuedForRegister) { // Paper
+ this.entitiesToAdd.add(entity);
+ entity.isQueuedForRegister = true; // Paper
+ }
} else {
+ entity.isQueuedForRegister = false; // Paper
this.entitiesById.put(entity.getId(), entity);
if (entity instanceof EntityEnderDragon) {
EntityComplexPart[] aentitycomplexpart = ((EntityEnderDragon) entity).eK();