Several fixes and new api for experience merging/stacking (#9242)

patches/server/0894-Implement-OfflinePlayer-isConnected.patch

@@ -0,0 +1,42 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Aeltumn <daniel@goossens.ch>
+Date: Thu, 24 Aug 2023 13:05:30 +0200
+Subject: [PATCH] Implement OfflinePlayer#isConnected
+
+
+diff --git a/src/main/java/org/bukkit/craftbukkit/CraftOfflinePlayer.java b/src/main/java/org/bukkit/craftbukkit/CraftOfflinePlayer.java
+index 4d654c4f0b6210a9841427789ba70ce5d1d308be..9d93130f23addb18b97d7f5ec013faef17a74529 100644
+--- a/src/main/java/org/bukkit/craftbukkit/CraftOfflinePlayer.java
++++ b/src/main/java/org/bukkit/craftbukkit/CraftOfflinePlayer.java
+@@ -54,6 +54,13 @@ public class CraftOfflinePlayer implements OfflinePlayer, ConfigurationSerializa
+         return this.getPlayer() != null;
+     }
+ 
++    // Paper start
++    @Override
++    public boolean isConnected() {
++        return false;
++    }
++    // Paper end
++
+     @Override
+     public String getName() {
+         Player player = this.getPlayer();
+diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+index 4e034c274964a651d6d91a7e1dc39c04e4fba184..5da5dc72a0ddb45515bce0ea81825f5368bbd997 100644
+--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
++++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+@@ -254,6 +254,13 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
+         return this.server.getPlayer(this.getUniqueId()) != null;
+     }
+ 
++    // Paper start
++    @Override
++    public boolean isConnected() {
++        return !this.getHandle().hasDisconnected();
++    }
++    // Paper end
++
+     @Override
+     public InetSocketAddress getAddress() {
+         if (this.getHandle().connection.protocol() == null) return null;