Let's hope this is fine

patches/server/Add-TickThread.patch

@@ -0,0 +1,105 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Spottedleaf <Spottedleaf@users.noreply.github.com>
+Date: Sun, 3 Mar 2019 20:53:18 -0800
+Subject: [PATCH] Add TickThread
+
+Placeholder patch, to be used by chunksystem rewrite
+
+diff --git a/src/main/java/io/papermc/paper/util/TickThread.java b/src/main/java/io/papermc/paper/util/TickThread.java
+new file mode 100644
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+--- /dev/null
++++ b/src/main/java/io/papermc/paper/util/TickThread.java
+@@ -0,0 +0,0 @@
++package io.papermc.paper.util;
++
++import net.minecraft.server.MinecraftServer;
++import net.minecraft.server.level.ServerLevel;
++import net.minecraft.world.entity.Entity;
++import org.bukkit.Bukkit;
++import java.util.concurrent.atomic.AtomicInteger;
++
++public final class TickThread extends Thread {
++
++    public static final boolean STRICT_THREAD_CHECKS = Boolean.getBoolean("paper.strict-thread-checks");
++
++    static {
++        if (STRICT_THREAD_CHECKS) {
++            MinecraftServer.LOGGER.warn("Strict thread checks enabled - performance may suffer");
++        }
++    }
++
++    public static void softEnsureTickThread(final String reason) {
++        if (!STRICT_THREAD_CHECKS) {
++            return;
++        }
++        ensureTickThread(reason);
++    }
++
++    public static void ensureTickThread(final String reason) {
++        if (!isTickThread()) {
++            MinecraftServer.LOGGER.error("Thread " + Thread.currentThread().getName() + " failed main thread check: " + reason, new Throwable());
++            throw new IllegalStateException(reason);
++        }
++    }
++
++    public static void ensureTickThread(final ServerLevel world, final int chunkX, final int chunkZ, final String reason) {
++        if (!isTickThreadFor(world, chunkX, chunkZ)) {
++            MinecraftServer.LOGGER.error("Thread " + Thread.currentThread().getName() + " failed main thread check: " + reason, new Throwable());
++            throw new IllegalStateException(reason);
++        }
++    }
++
++    public static void ensureTickThread(final Entity entity, final String reason) {
++        if (!isTickThreadFor(entity)) {
++            MinecraftServer.LOGGER.error("Thread " + Thread.currentThread().getName() + " failed main thread check: " + reason, new Throwable());
++            throw new IllegalStateException(reason);
++        }
++    }
++
++    public final int id; /* We don't override getId as the spec requires that it be unique (with respect to all other threads) */
++
++    private static final AtomicInteger ID_GENERATOR = new AtomicInteger();
++
++    public TickThread(final String name) {
++        this(null, name);
++    }
++
++    public TickThread(final Runnable run, final String name) {
++        this(run, name, ID_GENERATOR.incrementAndGet());
++    }
++
++    private TickThread(final Runnable run, final String name, final int id) {
++        super(run, name);
++        this.id = id;
++    }
++
++    public static TickThread getCurrentTickThread() {
++        return (TickThread)Thread.currentThread();
++    }
++
++    public static boolean isTickThread() {
++        return Bukkit.isPrimaryThread();
++    }
++
++    public static boolean isTickThreadFor(final ServerLevel world, final int chunkX, final int chunkZ) {
++        return Bukkit.isPrimaryThread();
++    }
++
++    public static boolean isTickThreadFor(final Entity entity) {
++        return Bukkit.isPrimaryThread();
++    }
++}
+diff --git a/src/main/java/org/spigotmc/AsyncCatcher.java b/src/main/java/org/spigotmc/AsyncCatcher.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/spigotmc/AsyncCatcher.java
++++ b/src/main/java/org/spigotmc/AsyncCatcher.java
+@@ -0,0 +0,0 @@ public class AsyncCatcher
+ 
+     public static void catchOp(String reason)
+     {
+-        if ( AsyncCatcher.enabled && Thread.currentThread() != MinecraftServer.getServer().serverThread )
++        if ( (AsyncCatcher.enabled || io.papermc.paper.util.TickThread.STRICT_THREAD_CHECKS) && Thread.currentThread() != MinecraftServer.getServer().serverThread ) // Paper
+         {
+             throw new IllegalStateException( "Asynchronous " + reason + "!" );
+         }

patches/server/Adventure.patch

@@ -2578,6 +2578,15 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
          }
          // CraftBukkit end
  
+@@ -0,0 +0,0 @@ public abstract class PlayerList {
+ 
+     }
+ 
+-    public String remove(ServerPlayer entityplayer) { // CraftBukkit - return string
++    public net.kyori.adventure.text.Component remove(ServerPlayer entityplayer) { // CraftBukkit - return string // Paper - return Component
+         ServerLevel worldserver = entityplayer.serverLevel();
+ 
+         entityplayer.awardStat(Stats.LEAVE_GAME);
 @@ -0,0 +0,0 @@ public abstract class PlayerList {
              entityplayer.closeContainer();
          }
@@ -2795,6 +2804,34 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
              ((ServerPlayer) player).connection.send(this.getUpdatePacket()); // CraftBukkit
          }
      }
+@@ -0,0 +0,0 @@ public class SignBlockEntity extends BlockEntity implements CommandSource { // C
+ 
+             // CraftBukkit start
+             Player player1 = ((ServerPlayer) player).getBukkitEntity();
+-            String[] lines = new String[4];
++            // Paper start
++            List<net.kyori.adventure.text.Component> lines = new java.util.ArrayList<>();
+ 
+             for (int j = 0; j < messages.size(); ++j) {
+-                lines[j] = CraftChatMessage.fromComponent(text.getMessage(j, player.isTextFilteringEnabled()));
++                lines.add(io.papermc.paper.adventure.PaperAdventure.asAdventure(text.getMessage(j, player.isTextFilteringEnabled())));
+             }
+ 
+             SignChangeEvent event = new SignChangeEvent(CraftBlock.at(this.level, this.worldPosition), player1, lines);
+             player.level().getCraftServer().getPluginManager().callEvent(event);
+ 
+             if (!event.isCancelled()) {
+-                Component[] components = org.bukkit.craftbukkit.block.CraftSign.sanitizeLines(event.getLines());
+-                for (int j = 0; j < components.length; j++) {
+-                    text = text.setMessage(j, components[j]);
++                // Paper start
++                for (int j = 0; j < 4; j++) {
++                    text = text.setMessage(j, io.papermc.paper.adventure.PaperAdventure.asVanilla(lines.get(j)));
+                 }
++                // Paper end
+             }
+             // CraftBukkit end
+         }
 diff --git a/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java b/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
 --- a/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java