Update Paper

The delta position packet instructs the client to update
the entity position by a position difference. However, this position
difference is relative to the last position in the entity tracker
state, not the last position which has been sent to the player. As
a result, if the last position the player has recorded is different
than the one stored in the entity tracker (which occurs when a new
player is added to an existing entity tracker state) then the sent
position difference will cause a position desync for the client.

We can resolve this problem by either tracking the last position
sent per-player, or by simply resetting the last sent position
in the entity tracker state every time a new player is added.
Resetting the last sent position every time a new player is
added to the tracker is just easier to do, so that is what
this patch does.

Fixes https://github.com/PaperMC/Folia/issues/197

gradle.properties

@@ -2,7 +2,7 @@ group=dev.folia
 
 version=1.20.4-R0.1-SNAPSHOT
 mcVersion=1.20.4
-paperRef=31699ae9a8f3a57491e9c9276cffa5a51e9a5f60
+paperRef=4939f8711884901ddf1c56337f606de71cdae78d
 
 org.gradle.caching=true
 org.gradle.parallel=true

patches/api/0003-Require-plugins-to-be-explicitly-marked-as-Folia-sup.patch

@@ -14,7 +14,7 @@ more helpful than some random error log caused by
 a breakage.
 
 diff --git a/src/main/java/io/papermc/paper/plugin/configuration/PluginMeta.java b/src/main/java/io/papermc/paper/plugin/configuration/PluginMeta.java
-index ef393f1f93ca48264fc1b6e3a27787f6a9152e1b..1325f9fed80731b74b80145dadc843b1a34b851b 100644
+index bcf91d048d84144f6acf9bfd2095df9ada2e585f..3072f95dc1cafb47c1820dc67c8d24991540fc4a 100644
 --- a/src/main/java/io/papermc/paper/plugin/configuration/PluginMeta.java
 +++ b/src/main/java/io/papermc/paper/plugin/configuration/PluginMeta.java
 @@ -200,4 +200,12 @@ public interface PluginMeta {

patches/server/0001-Build-changes.patch

@@ -5,7 +5,7 @@ Subject: [PATCH] Build changes
 
 
 diff --git a/build.gradle.kts b/build.gradle.kts
-index 376e8983fdfdbb6c3e5fd8ad0f6a05e655b622bf..959e62d800de05b2dd77a252f442c3daf8438490 100644
+index ce3747d8d2a8f4327766cf23d5aaa72cfcb380bc..08d434023226af0d2c469055a3b2188fe8a4ed38 100644
 --- a/build.gradle.kts
 +++ b/build.gradle.kts
 @@ -13,8 +13,12 @@ configurations.named(log4jPlugins.compileClasspathConfigurationName) {
@@ -23,7 +23,7 @@ index 376e8983fdfdbb6c3e5fd8ad0f6a05e655b622bf..959e62d800de05b2dd77a252f442c3da
      // Paper start
      implementation("org.jline:jline-terminal-jansi:3.21.0")
      implementation("net.minecrell:terminalconsoleappender:1.3.0")
-@@ -69,7 +73,7 @@ tasks.jar {
+@@ -70,7 +74,7 @@ tasks.jar {
          attributes(
              "Main-Class" to "org.bukkit.craftbukkit.Main",
              "Implementation-Title" to "CraftBukkit",
@@ -32,7 +32,7 @@ index 376e8983fdfdbb6c3e5fd8ad0f6a05e655b622bf..959e62d800de05b2dd77a252f442c3da
              "Implementation-Vendor" to date, // Paper
              "Specification-Title" to "Bukkit",
              "Specification-Version" to project.version,
-@@ -153,7 +157,7 @@ fun TaskContainer.registerRunTask(
+@@ -154,7 +158,7 @@ fun TaskContainer.registerRunTask(
      name: String,
      block: JavaExec.() -> Unit
  ): TaskProvider<JavaExec> = register<JavaExec>(name) {

patches/server/0011-Prevent-block-updates-in-non-loaded-or-non-owned-chu.patch

@@ -54,7 +54,7 @@ index b84c48902ef24fdae17578a304e6c93dc20c5dce..218c1954a7922c9e6bf6f34f9497f89c
          } else {
              RailShape blockpropertytrackposition1 = (RailShape) iblockdata.getValue(PoweredRailBlock.SHAPE);
 diff --git a/src/main/java/net/minecraft/world/level/block/RedStoneWireBlock.java b/src/main/java/net/minecraft/world/level/block/RedStoneWireBlock.java
-index 18cb719ae55b736a6dade61237a845c866fb6858..306e8dc1546927def934148c0c542c48872544e7 100644
+index 1fd29331e928bc76de06d5eb5ba781390af76ebe..d6df2f1d3342fcbcf8ee5aa86c4d6f3431fac580 100644
 --- a/src/main/java/net/minecraft/world/level/block/RedStoneWireBlock.java
 +++ b/src/main/java/net/minecraft/world/level/block/RedStoneWireBlock.java
 @@ -200,8 +200,9 @@ public class RedStoneWireBlock extends Block {

patches/server/0013-Skip-worldstate-access-when-waking-players-up-during.patch

@@ -22,7 +22,7 @@ index add6fc106d3c38d97b48ec0df3ac2515c8c0486e..cbc89b8898f9243776af88c2b04ad3c2
  
          // CraftBukkit start
 diff --git a/src/main/java/net/minecraft/world/entity/LivingEntity.java b/src/main/java/net/minecraft/world/entity/LivingEntity.java
-index a463c46778e5ee641c1b7d634b79ec68414cd936..b640d877f924094bcabbf9618bbd9aa0a70bf94a 100644
+index ffec458e5b6dc4250758fb8a97ab1e737dcedb1d..2fa76a711a629e38a95b93e473272b8217783f99 100644
 --- a/src/main/java/net/minecraft/world/entity/LivingEntity.java
 +++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java
 @@ -4374,6 +4374,11 @@ public abstract class LivingEntity extends Entity implements Attackable {

patches/server/0018-Region-profiler.patch

@@ -1629,10 +1629,10 @@ index d532043f33825ce2971d9e53f290cdead22d6916..74483543836d9ed042cc7b9cbbde8d58
              // Folia end - region threading
              // Paper end - optimise chunk tick iteration
 diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
-index 172f8e1abb036669b787fde570da8d326d2ab262..a16fc5ba55dbde0cf7f968884da40d70a754a0d8 100644
+index a74538bdc720efc435e7890aa835c9f255f9ebb6..ec25610cbffe30fecaeaadf9098e187bc15b5405 100644
 --- a/src/main/java/net/minecraft/server/level/ServerLevel.java
 +++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
-@@ -892,6 +892,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
+@@ -891,6 +891,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
  
      public void tick(BooleanSupplier shouldKeepTicking, io.papermc.paper.threadedregions.TickRegions.TickRegionData region) { // Folia - regionised ticking
          final io.papermc.paper.threadedregions.RegionizedWorldData regionizedWorldData = this.getCurrentWorldData(); // Folia - regionised ticking
@@ -1640,7 +1640,7 @@ index 172f8e1abb036669b787fde570da8d326d2ab262..a16fc5ba55dbde0cf7f968884da40d70
          ProfilerFiller gameprofilerfiller = this.getProfiler();
  
          regionizedWorldData.setHandlingTick(true); // Folia - regionised ticking
-@@ -920,9 +921,13 @@ public class ServerLevel extends Level implements WorldGenLevel {
+@@ -919,9 +920,13 @@ public class ServerLevel extends Level implements WorldGenLevel {
          if (!this.isDebug() && flag) {
              j = regionizedWorldData.getRedstoneGameTime(); // Folia - region threading
              gameprofilerfiller.push("blockTicks");
@@ -1654,7 +1654,7 @@ index 172f8e1abb036669b787fde570da8d326d2ab262..a16fc5ba55dbde0cf7f968884da40d70
              gameprofilerfiller.pop();
          }
          this.timings.scheduledBlocks.stopTiming(); // Paper
-@@ -930,18 +935,24 @@ public class ServerLevel extends Level implements WorldGenLevel {
+@@ -929,18 +934,24 @@ public class ServerLevel extends Level implements WorldGenLevel {
          gameprofilerfiller.popPush("raid");
          if (flag) {
              this.timings.raids.startTiming(); // Paper - timings
@@ -1679,7 +1679,7 @@ index 172f8e1abb036669b787fde570da8d326d2ab262..a16fc5ba55dbde0cf7f968884da40d70
              this.timings.doSounds.stopTiming(); // Spigot
          }
  
-@@ -957,6 +968,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
+@@ -956,6 +967,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
              gameprofilerfiller.push("entities");
              this.timings.tickEntities.startTiming(); // Spigot
              if (this.dragonFight != null && flag) {
@@ -1687,7 +1687,7 @@ index 172f8e1abb036669b787fde570da8d326d2ab262..a16fc5ba55dbde0cf7f968884da40d70
                  if (io.papermc.paper.util.TickThread.isTickThreadFor(this, this.dragonFight.origin)) { // Folia - region threading
                  gameprofilerfiller.push("dragonFight");
                  this.dragonFight.tick();
-@@ -969,10 +981,12 @@ public class ServerLevel extends Level implements WorldGenLevel {
+@@ -968,10 +980,12 @@ public class ServerLevel extends Level implements WorldGenLevel {
                          fightCenter
                      );
                  } // Folia end - region threading
@@ -1700,7 +1700,7 @@ index 172f8e1abb036669b787fde570da8d326d2ab262..a16fc5ba55dbde0cf7f968884da40d70
              regionizedWorldData.forEachTickingEntity((entity) -> { // Folia - regionised ticking
                  if (!entity.isRemoved()) {
                      if (false && this.shouldDiscardEntity(entity)) { // CraftBukkit - We prevent spawning in general, so this butchering is not needed
-@@ -1000,10 +1014,13 @@ public class ServerLevel extends Level implements WorldGenLevel {
+@@ -999,10 +1013,13 @@ public class ServerLevel extends Level implements WorldGenLevel {
                      }
                  }
              });
@@ -1714,7 +1714,7 @@ index 172f8e1abb036669b787fde570da8d326d2ab262..a16fc5ba55dbde0cf7f968884da40d70
          }
  
          gameprofilerfiller.push("entityManagement");
-@@ -1063,12 +1080,15 @@ public class ServerLevel extends Level implements WorldGenLevel {
+@@ -1062,12 +1079,15 @@ public class ServerLevel extends Level implements WorldGenLevel {
      }
  
      public void tickCustomSpawners(boolean spawnMonsters, boolean spawnAnimals) {
@@ -1730,7 +1730,7 @@ index 172f8e1abb036669b787fde570da8d326d2ab262..a16fc5ba55dbde0cf7f968884da40d70
          }
  
      }
-@@ -1518,6 +1538,11 @@ public class ServerLevel extends Level implements WorldGenLevel {
+@@ -1517,6 +1537,11 @@ public class ServerLevel extends Level implements WorldGenLevel {
          // Paper start- timings
          final boolean isActive = org.spigotmc.ActivationRange.checkIfActive(entity);
          timer = isActive ? entity.getType().tickTimer.startTiming() : entity.getType().inactiveTickTimer.startTiming(); // Paper
@@ -1742,7 +1742,7 @@ index 172f8e1abb036669b787fde570da8d326d2ab262..a16fc5ba55dbde0cf7f968884da40d70
          try {
          // Paper end - timings
          entity.setOldPosAndRot();
-@@ -1543,7 +1568,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
+@@ -1542,7 +1567,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
          // Folia end - region threading
          } else { entity.inactiveTick(); } // Paper - EAR 2
          this.getProfiler().pop();
@@ -1751,7 +1751,7 @@ index 172f8e1abb036669b787fde570da8d326d2ab262..a16fc5ba55dbde0cf7f968884da40d70
          Iterator iterator = entity.getPassengers().iterator();
  
          while (iterator.hasNext()) {
-@@ -1567,6 +1592,11 @@ public class ServerLevel extends Level implements WorldGenLevel {
+@@ -1566,6 +1591,11 @@ public class ServerLevel extends Level implements WorldGenLevel {
                  // Paper - EAR 2
                  final boolean isActive = org.spigotmc.ActivationRange.checkIfActive(passenger);
                  co.aikar.timings.Timing timer = isActive ? passenger.getType().passengerTickTimer.startTiming() : passenger.getType().passengerInactiveTickTimer.startTiming(); // Paper
@@ -1763,7 +1763,7 @@ index 172f8e1abb036669b787fde570da8d326d2ab262..a16fc5ba55dbde0cf7f968884da40d70
                  try {
                  // Paper end
                  passenger.setOldPosAndRot();
-@@ -1606,7 +1636,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
+@@ -1605,7 +1635,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
                      this.tickPassenger(passenger, entity2);
                  }
  

patches/server/0019-Fix-entity-tracker-desync-when-new-players-are-added.patch

@@ -0,0 +1,85 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Spottedleaf <Spottedleaf@users.noreply.github.com>
+Date: Tue, 20 Feb 2024 18:24:16 -0800
+Subject: [PATCH] Fix entity tracker desync when new players are added to the
+ tracker
+
+The delta position packet instructs the client to update
+the entity position by a position difference. However, this position
+difference is relative to the last position in the entity tracker
+state, not the last position which has been sent to the player. As
+a result, if the last position the player has recorded is different
+than the one stored in the entity tracker (which occurs when a new
+player is added to an existing entity tracker state) then the sent
+position difference will cause a position desync for the client.
+
+We can resolve this problem by either tracking the last position
+sent per-player, or by simply resetting the last sent position
+in the entity tracker state every time a new player is added.
+Resetting the last sent position every time a new player is
+added to the tracker is just easier to do, so that is what
+this patch does.
+
+diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
+index 21ec49acb3c1241d9286959c42a7f8363f637e4f..79e507c1463dbb9039b1fed8bdf41c0ee5f4fec3 100644
+--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
++++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
+@@ -1419,6 +1419,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
+                         this.serverEntity.addPairing(player);
+                         }
+                         // Paper end - entity tracking events
++                        this.serverEntity.onPlayerAdd(); // Paper - fix desync when a player is added to the tracker
+                     }
+                 } else if (this.seenBy.remove(player.connection)) {
+                     this.serverEntity.removePairing(player);
+diff --git a/src/main/java/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java
+index 529ab44baaf573b97cf7e89560c548642733188f..16373e0c5ea38199fab3eb289bf2a5fcf0dd7439 100644
+--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
++++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
+@@ -93,6 +93,13 @@ public class ServerEntity {
+         this.trackedDataValues = entity.getEntityData().getNonDefaultValues();
+     }
+ 
++    // Paper start - fix desync when a player is added to the tracker
++    private boolean forceStateResync;
++    public void onPlayerAdd() {
++        this.forceStateResync = true;
++    }
++    // Paper end - fix desync when a player is added to the tracker
++
+     public void sendChanges() {
+         List<Entity> list = this.entity.getPassengers();
+ 
+@@ -141,7 +148,7 @@ public class ServerEntity {
+             }
+         }
+ 
+-        if (this.tickCount % this.updateInterval == 0 || this.entity.hasImpulse || this.entity.getEntityData().isDirty()) {
++        if (this.forceStateResync || this.tickCount % this.updateInterval == 0 || this.entity.hasImpulse || this.entity.getEntityData().isDirty()) { // Paper - fix desync when a player is added to the tracker
+             int i;
+             int j;
+ 
+@@ -177,13 +184,13 @@ public class ServerEntity {
+                 boolean flag4 = false;
+                 boolean flag5 = false;
+ 
+-                if (!(this.entity instanceof net.minecraft.world.entity.decoration.HangingEntity) || this.tickCount > 0 || this.entity instanceof AbstractArrow) { // Paper - Always update position to fix first-tick teleports
++                if (this.forceStateResync || !(this.entity instanceof net.minecraft.world.entity.decoration.HangingEntity) || this.tickCount > 0 || this.entity instanceof AbstractArrow) { // Paper - Always update position to fix first-tick teleports
+                     long k = this.positionCodec.encodeX(vec3d);
+                     long l = this.positionCodec.encodeY(vec3d);
+                     long i1 = this.positionCodec.encodeZ(vec3d);
+                     boolean flag6 = k < -32768L || k > 32767L || l < -32768L || l > 32767L || i1 < -32768L || i1 > 32767L;
+ 
+-                    if (!flag6 && this.teleportDelay <= 400 && !this.wasRiding && this.wasOnGround == this.entity.onGround()&& !(io.papermc.paper.configuration.GlobalConfiguration.get().collisions.sendFullPosForHardCollidingEntities && this.entity.hardCollides())) { // Paper - send full pos for hard colliding entities to prevent collision problems due to desync
++                    if (!this.forceStateResync && !flag6 && this.teleportDelay <= 400 && !this.wasRiding && this.wasOnGround == this.entity.onGround()&& !(io.papermc.paper.configuration.GlobalConfiguration.get().collisions.sendFullPosForHardCollidingEntities && this.entity.hardCollides())) { // Paper - send full pos for hard colliding entities to prevent collision problems due to desync
+                         if ((!flag2 || !flag3) && !(this.entity instanceof AbstractArrow)) {
+                             if (flag2) {
+                                 packet1 = new ClientboundMoveEntityPacket.Pos(this.entity.getId(), (short) ((int) k), (short) ((int) l), (short) ((int) i1), this.entity.onGround());
+@@ -240,6 +247,7 @@ public class ServerEntity {
+             }
+ 
+             this.entity.hasImpulse = false;
++            this.forceStateResync = false; // Paper - fix desync when a player is added to the tracker
+         }
+ 
+         ++this.tickCount;