Fix StackOverflowException thrown on shutdown (Fixes #10404) (#10408)

paper previously migrated away from using executeIfPossible as this throws a
RejectedExecutionException when the server is shutting down, which is then picked
up by the Connection handler object and causes the player to be kicked without
the intended disconnection message that comes from commands such as /stop, /restart

This was fine, because previously changes made in spigot would just prevent these
packets from being executed anyways. Instead, we'll just use a marker exception
to try to detect this specific state.

patches/server/Detail-more-information-in-watchdog-dumps.patch

@@ -56,7 +56,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 @@ -0,0 +0,0 @@ public class PacketUtils {
      public static <T extends PacketListener> void ensureRunningOnSameThread(Packet<T> packet, T listener, BlockableEventLoop<?> engine) throws RunningOnDifferentThreadException {
          if (!engine.isSameThread()) {
-             engine.execute(() -> { // Paper - Fix preemptive player kick on a server shutdown
+             engine.executeIfPossible(() -> {
 +                packetProcessing.push(listener); // Paper - detailed watchdog information
 +                try { // Paper - detailed watchdog information
                  if (listener instanceof ServerCommonPacketListenerImpl serverCommonPacketListener && serverCommonPacketListener.processedDisconnect) return; // CraftBukkit - Don't handle sync packets for kicked players

patches/server/Fix-player-kick-on-shutdown.patch

@@ -1,23 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Denery <dorofeevij@gmail.com>
-Date: Sun, 6 Nov 2022 02:02:46 +0300
-Subject: [PATCH] Fix player kick on shutdown
-
-Fix preemptive player kick on a server shutdown.
-If you update minecraft version / upstream and something is changed in this method make sure that a server doesn't disconnect a player preemptively,
-also check if all packets are ignored during the shutdown process.
-See net.minecraft.network.Connection#channelRead0(ChannelHandlerContext, Packet) and net.minecraft.util.thread.BlockableEventLoop#executeIfPossible(Runnable)
-
-diff --git a/src/main/java/net/minecraft/network/protocol/PacketUtils.java b/src/main/java/net/minecraft/network/protocol/PacketUtils.java
-index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
---- a/src/main/java/net/minecraft/network/protocol/PacketUtils.java
-+++ b/src/main/java/net/minecraft/network/protocol/PacketUtils.java
-@@ -0,0 +0,0 @@ public class PacketUtils {
- 
-     public static <T extends PacketListener> void ensureRunningOnSameThread(Packet<T> packet, T listener, BlockableEventLoop<?> engine) throws RunningOnDifferentThreadException {
-         if (!engine.isSameThread()) {
--            engine.executeIfPossible(() -> {
-+            engine.execute(() -> { // Paper - Fix preemptive player kick on a server shutdown
-                 if (listener instanceof ServerCommonPacketListenerImpl serverCommonPacketListener && serverCommonPacketListener.processedDisconnect) return; // CraftBukkit - Don't handle sync packets for kicked players
-                 if (listener.shouldHandleMessage(packet)) {
-                     co.aikar.timings.Timing timing = co.aikar.timings.MinecraftTimings.getPacketTiming(packet); // Paper - timings

patches/server/Fix-premature-player-kicks-on-shutdown.patch

@@ -0,0 +1,61 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Shane Freeder <theboyetronic@gmail.com>
+Date: Thu, 11 Apr 2024 16:37:44 +0100
+Subject: [PATCH] Fix premature player kicks on shutdown
+
+When the server is stopping, the default execution handler method will throw a
+RejectedExecutionException in order to prevent further execution, this causes
+us to lose the actual kick reason. To mitigate this, we'll use a seperate marked
+class in order to gracefully ignore these.
+
+diff --git a/src/main/java/io/papermc/paper/util/ServerStopRejectedExecutionException.java b/src/main/java/io/papermc/paper/util/ServerStopRejectedExecutionException.java
+new file mode 100644
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+--- /dev/null
++++ b/src/main/java/io/papermc/paper/util/ServerStopRejectedExecutionException.java
+@@ -0,0 +0,0 @@
++package io.papermc.paper.util;
++
++import java.util.concurrent.RejectedExecutionException;
++
++public class ServerStopRejectedExecutionException extends RejectedExecutionException {
++    public ServerStopRejectedExecutionException() {
++    }
++
++    public ServerStopRejectedExecutionException(final String message) {
++        super(message);
++    }
++
++    public ServerStopRejectedExecutionException(final String message, final Throwable cause) {
++        super(message, cause);
++    }
++
++    public ServerStopRejectedExecutionException(final Throwable cause) {
++        super(cause);
++    }
++}
+diff --git a/src/main/java/net/minecraft/network/Connection.java b/src/main/java/net/minecraft/network/Connection.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/network/Connection.java
++++ b/src/main/java/net/minecraft/network/Connection.java
+@@ -0,0 +0,0 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+                         Connection.genericsFtw(packet, packetlistener);
+                     } catch (RunningOnDifferentThreadException cancelledpackethandleexception) {
+                         ;
++                    } catch (io.papermc.paper.util.ServerStopRejectedExecutionException ignored) { // Paper - do not prematurely disconnect players on stop
+                     } catch (RejectedExecutionException rejectedexecutionexception) {
+                         this.disconnect(Component.translatable("multiplayer.disconnect.server_shutdown"));
+                     } catch (ClassCastException classcastexception) {
+diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/MinecraftServer.java
++++ b/src/main/java/net/minecraft/server/MinecraftServer.java
+@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+     @Override
+     public void executeIfPossible(Runnable runnable) {
+         if (this.isStopped()) {
+-            throw new RejectedExecutionException("Server already shutting down");
++            throw new io.papermc.paper.util.ServerStopRejectedExecutionException("Server already shutting down"); // Paper - do not prematurely disconnect players on stop
+         } else {
+             super.executeIfPossible(runnable);
+         }