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..2c5cd77103c5a33d4349ab6b9ee2d8378bb60eb4
--- /dev/null
+++ b/src/main/java/io/papermc/paper/util/ServerStopRejectedExecutionException.java
@@ -0,0 +1,20 @@
+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 22a7f17180b76b6c3548d3b54ae8218a469401a8..c399625a342ffd61102bb96a97ac24b0669e8e17 100644
--- a/src/main/java/net/minecraft/network/Connection.java
+++ b/src/main/java/net/minecraft/network/Connection.java
@@ -290,6 +290,7 @@ 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 bfee202e1dc8ea875b9d2b4e8c3b0be3f6d94b26..d50d3bc9c0f573cdb43100bce6e3dbfe2102fc53 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -2013,7 +2013,7 @@ 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);
         }