Prevent Ghost Players Caused by Plugins

Check if the player is still connected after firing event. Fixes BUKKIT-4327

By: Alex Ciuba <alexciuba@gmail.com>

paper-server/patches/sources/net/minecraft/server/level/ServerPlayer.java.patch

@@ -112,10 +112,11 @@
      @Nullable
      private Vec3 startingToFallPosition;
      @Nullable
-@@ -259,6 +292,22 @@
+@@ -258,6 +291,22 @@
+     private final CommandSource commandSource;
      private int containerCounter;
      public boolean wonGame;
- 
++
 +    // CraftBukkit start
 +    public CraftPlayer.TransferCookieConnection transferCookieConnection;
 +    public String displayName;
@@ -131,10 +132,9 @@
 +    public boolean sentListPacket = false;
 +    public String kickLeaveMessage = null; // SPIGOT-3034: Forward leave message to PlayerQuitEvent
 +    // CraftBukkit end
-+
+ 
      public ServerPlayer(MinecraftServer server, ServerLevel world, GameProfile profile, ClientInformation clientOptions) {
          super(world, world.getSharedSpawnPos(), world.getSharedSpawnAngle(), profile);
-         this.chatVisibility = ChatVisiblity.FULL;
 @@ -340,6 +389,13 @@
              public void sendSystemMessage(Component message) {
                  ServerPlayer.this.sendSystemMessage(message);
@@ -158,8 +158,8 @@
 +        this.displayName = this.getScoreboardName();
 +        this.bukkitPickUpLoot = true;
 +        this.maxHealthCache = this.getMaxHealth();
-     }
++    }
- 
++
 +    // Use method to resend items in hands in case of client desync, because the item use got cancelled.
 +    // For example, when cancelling the leash event
 +    public void resendItemInHands() {
@@ -205,9 +205,9 @@
 +        }
 +
 +        return blockposition;
-+    }
+     }
 +    // CraftBukkit end
-+
+ 
      @Override
      public BlockPos adjustSpawnLocation(ServerLevel world, BlockPos basePos) {
          AABB axisalignedbb = this.getDimensions(Pose.STANDING).makeBoundingBox(Vec3.ZERO);
@@ -588,7 +588,7 @@
  
                      if (!this.canHarmPlayer(entityhuman1)) {
                          return false;
-@@ -1088,33 +1322,58 @@
+@@ -1088,33 +1322,63 @@
      }
  
      @Override
@@ -646,6 +646,11 @@
 +
 +        PlayerRespawnEvent respawnEvent = new PlayerRespawnEvent(respawnPlayer, location, isBedSpawn, isAnchorSpawn, reason);
 +        this.level().getCraftServer().getPluginManager().callEvent(respawnEvent);
++        // Spigot Start
++        if (this.connection.isDisconnected()) {
++            return null;
++        }
++        // Spigot End
 +
 +        location = respawnEvent.getRespawnLocation();
 +
@@ -654,7 +659,7 @@
      }
  
      public static Optional<ServerPlayer.RespawnPosAngle> findRespawnAndUseSpawnBlock(ServerLevel world, BlockPos pos, float spawnAngle, boolean spawnForced, boolean alive) {
-@@ -1129,11 +1388,11 @@
+@@ -1129,11 +1393,11 @@
              }
  
              return optional.map((vec3d) -> {
@@ -668,7 +673,7 @@
              });
          } else if (!spawnForced) {
              return Optional.empty();
-@@ -1142,7 +1401,7 @@
+@@ -1142,7 +1406,7 @@
              BlockState iblockdata1 = world.getBlockState(pos.above());
              boolean flag3 = iblockdata1.getBlock().isPossibleToRespawnInThis(iblockdata1);
  
@@ -677,7 +682,7 @@
          }
      }
  
-@@ -1160,6 +1419,7 @@
+@@ -1160,6 +1424,7 @@
      @Nullable
      @Override
      public ServerPlayer teleport(TeleportTransition teleportTarget) {
@@ -685,7 +690,7 @@
          if (this.isRemoved()) {
              return null;
          } else {
-@@ -1169,39 +1429,73 @@
+@@ -1169,39 +1434,73 @@
  
              ServerLevel worldserver = teleportTarget.newLevel();
              ServerLevel worldserver1 = this.serverLevel();
@@ -767,7 +772,7 @@
                  this.connection.resetPosition();
                  worldserver.addDuringTeleport(this);
                  gameprofilerfiller.pop();
-@@ -1215,12 +1509,30 @@
+@@ -1215,12 +1514,30 @@
                  this.lastSentExp = -1;
                  this.lastSentHealth = -1.0F;
                  this.lastSentFood = -1;
@@ -798,7 +803,7 @@
      public void forceSetRotation(float yaw, float pitch) {
          this.connection.send(new ClientboundPlayerRotationPacket(yaw, pitch));
      }
-@@ -1228,13 +1540,21 @@
+@@ -1228,13 +1545,21 @@
      public void triggerDimensionChangeTriggers(ServerLevel origin) {
          ResourceKey<Level> resourcekey = origin.dimension();
          ResourceKey<Level> resourcekey1 = this.level().dimension();
@@ -823,7 +828,7 @@
              this.enteredNetherPosition = null;
          }
  
-@@ -1251,36 +1571,63 @@
+@@ -1251,36 +1576,63 @@
          this.containerMenu.broadcastChanges();
      }
  
@@ -902,7 +907,7 @@
                          this.awardStat(Stats.SLEEP_IN_BED);
                          CriteriaTriggers.SLEPT_IN_BED.trigger(this);
                      });
-@@ -1293,9 +1640,8 @@
+@@ -1293,9 +1645,8 @@
                      return either;
                  }
              }
@@ -913,7 +918,7 @@
      }
  
      @Override
-@@ -1322,13 +1668,31 @@
+@@ -1322,13 +1673,31 @@
  
      @Override
      public void stopSleepInBed(boolean skipSleepTimer, boolean updateSleepingPlayers) {
@@ -946,7 +951,7 @@
          }
  
      }
-@@ -1387,8 +1751,9 @@
+@@ -1387,8 +1756,9 @@
          this.connection.send(new ClientboundOpenSignEditorPacket(sign.getBlockPos(), front));
      }
  
@@ -957,7 +962,7 @@
      }
  
      @Override
-@@ -1396,13 +1761,35 @@
+@@ -1396,13 +1766,35 @@
          if (factory == null) {
              return OptionalInt.empty();
          } else {
@@ -993,7 +998,7 @@
              if (container == null) {
                  if (this.isSpectator()) {
                      this.displayClientMessage(Component.translatable("container.spectatorCantOpen").withStyle(ChatFormatting.RED), true);
-@@ -1410,9 +1797,11 @@
+@@ -1410,9 +1802,11 @@
  
                  return OptionalInt.empty();
              } else {
@@ -1007,7 +1012,7 @@
                  return OptionalInt.of(this.containerCounter);
              }
          }
-@@ -1425,15 +1814,26 @@
+@@ -1425,15 +1819,26 @@
  
      @Override
      public void openHorseInventory(AbstractHorse horse, Container inventory) {
@@ -1036,7 +1041,7 @@
          this.initMenu(this.containerMenu);
      }
  
-@@ -1456,6 +1856,7 @@
+@@ -1456,6 +1861,7 @@
  
      @Override
      public void closeContainer() {
@@ -1044,7 +1049,7 @@
          this.connection.send(new ClientboundContainerClosePacket(this.containerMenu.containerId));
          this.doCloseContainer();
      }
-@@ -1485,19 +1886,19 @@
+@@ -1485,19 +1891,19 @@
                  i = Math.round((float) Math.sqrt(deltaX * deltaX + deltaY * deltaY + deltaZ * deltaZ) * 100.0F);
                  if (i > 0) {
                      this.awardStat(Stats.SWIM_ONE_CM, i);
@@ -1067,7 +1072,7 @@
                  }
              } else if (this.onClimbable()) {
                  if (deltaY > 0.0D) {
-@@ -1508,13 +1909,13 @@
+@@ -1508,13 +1914,13 @@
                  if (i > 0) {
                      if (this.isSprinting()) {
                          this.awardStat(Stats.SPRINT_ONE_CM, i);
@@ -1084,7 +1089,7 @@
                      }
                  }
              } else if (this.isFallFlying()) {
-@@ -1557,7 +1958,7 @@
+@@ -1557,7 +1963,7 @@
      @Override
      public void awardStat(Stat<?> stat, int amount) {
          this.stats.increment(this, stat, amount);
@@ -1093,7 +1098,7 @@
              scoreaccess.add(amount);
          });
      }
-@@ -1565,7 +1966,7 @@
+@@ -1565,7 +1971,7 @@
      @Override
      public void resetStat(Stat<?> stat) {
          this.stats.setValue(this, stat, 0);
@@ -1102,7 +1107,7 @@
      }
  
      @Override
-@@ -1597,9 +1998,9 @@
+@@ -1597,9 +2003,9 @@
          super.jumpFromGround();
          this.awardStat(Stats.JUMP);
          if (this.isSprinting()) {
@@ -1114,7 +1119,7 @@
          }
  
      }
-@@ -1625,6 +2026,7 @@
+@@ -1625,6 +2031,7 @@
  
      public void resetSentInfo() {
          this.lastSentHealth = -1.0E8F;
@@ -1122,7 +1127,7 @@
      }
  
      @Override
-@@ -1661,7 +2063,7 @@
+@@ -1661,7 +2068,7 @@
          this.onUpdateAbilities();
          if (alive) {
              this.getAttributes().assignBaseValues(oldPlayer.getAttributes());
@@ -1131,7 +1136,7 @@
              this.setHealth(oldPlayer.getHealth());
              this.foodData = oldPlayer.foodData;
              Iterator iterator = oldPlayer.getActiveEffects().iterator();
-@@ -1669,7 +2071,7 @@
+@@ -1669,7 +2076,7 @@
              while (iterator.hasNext()) {
                  MobEffectInstance mobeffect = (MobEffectInstance) iterator.next();
  
@@ -1140,7 +1145,7 @@
              }
  
              this.getInventory().replaceWith(oldPlayer.getInventory());
-@@ -1680,7 +2082,7 @@
+@@ -1680,7 +2087,7 @@
              this.portalProcess = oldPlayer.portalProcess;
          } else {
              this.getAttributes().assignBaseValues(oldPlayer.getAttributes());
@@ -1149,7 +1154,7 @@
              if (this.serverLevel().getGameRules().getBoolean(GameRules.RULE_KEEPINVENTORY) || oldPlayer.isSpectator()) {
                  this.getInventory().replaceWith(oldPlayer.getInventory());
                  this.experienceLevel = oldPlayer.experienceLevel;
-@@ -1696,7 +2098,7 @@
+@@ -1696,7 +2103,7 @@
          this.lastSentExp = -1;
          this.lastSentHealth = -1.0F;
          this.lastSentFood = -1;
@@ -1158,7 +1163,7 @@
          this.seenCredits = oldPlayer.seenCredits;
          this.enteredNetherPosition = oldPlayer.enteredNetherPosition;
          this.chunkTrackingView = oldPlayer.chunkTrackingView;
-@@ -1752,19 +2154,19 @@
+@@ -1752,19 +2159,19 @@
      }
  
      @Override
@@ -1182,7 +1187,7 @@
          }
  
          return flag1;
-@@ -1878,6 +2280,16 @@
+@@ -1878,6 +2285,16 @@
      }
  
      public void updateOptions(ClientInformation clientOptions) {
@@ -1199,7 +1204,7 @@
          this.language = clientOptions.language();
          this.requestedViewDistance = clientOptions.viewDistance();
          this.chatVisibility = clientOptions.chatVisibility();
-@@ -1962,7 +2374,7 @@
+@@ -1962,7 +2379,7 @@
              if (world instanceof ServerLevel) {
                  ServerLevel worldserver = (ServerLevel) world;
  
@@ -1208,7 +1213,7 @@
              }
  
              if (entity != null) {
-@@ -1999,11 +2411,11 @@
+@@ -1999,11 +2416,11 @@
  
      @Nullable
      public Component getTabListDisplayName() {
@@ -1222,7 +1227,7 @@
      }
  
      @Override
-@@ -2046,17 +2458,43 @@
+@@ -2046,17 +2463,43 @@
      }
  
      public void setRespawnPosition(ResourceKey<Level> dimension, @Nullable BlockPos pos, float angle, boolean forced, boolean sendMessage) {
@@ -1273,7 +1278,7 @@
          } else {
              this.respawnPosition = null;
              this.respawnDimension = Level.OVERWORLD;
-@@ -2088,18 +2526,44 @@
+@@ -2088,18 +2531,44 @@
      }
  
      @Override
@@ -1322,7 +1327,7 @@
                  }
  
                  this.awardStat(Stats.DROP);
-@@ -2375,16 +2839,160 @@
+@@ -2375,16 +2844,160 @@
          return TicketType.ENDER_PEARL.timeout();
      }
  
@@ -1355,8 +1360,8 @@
 +        } else {
 +            // Adds timeOffset to the beginning of this day.
 +            return this.level().getDayTime() - (this.level().getDayTime() % 24000) + this.timeOffset;
-+        }
+         }
-+    }
+     }
 +
 +    public WeatherType weather = null;
 +
@@ -1394,7 +1399,7 @@
 +            if (this.pluginRainPositionPrevious != this.pluginRainPosition) {
 +                this.connection.send(new ClientboundGameEventPacket(ClientboundGameEventPacket.RAIN_LEVEL_CHANGE, this.pluginRainPosition));
 +            }
-         }
++        }
 +
 +        if (oldThunder != newThunder) {
 +            if (this.weather == WeatherType.DOWNFALL || this.weather == null) {
@@ -1403,7 +1408,7 @@
 +                this.connection.send(new ClientboundGameEventPacket(ClientboundGameEventPacket.THUNDER_LEVEL_CHANGE, 0));
 +            }
 +        }
-     }
++    }
 +
 +    public void tickWeather() {
 +        if (this.weather == null) return;

paper-server/patches/sources/net/minecraft/server/players/PlayerList.java.patch

@@ -460,11 +460,10 @@
              }
  
 -            return ichatmutablecomponent;
--        } else {
--            return this.players.size() >= this.maxPlayers && !this.canBypassPlayerLimit(profile) ? Component.translatable("multiplayer.disconnect.server_full") : null;
 +            // return chatmessage;
 +            event.disallow(PlayerLoginEvent.Result.KICK_BANNED, CraftChatMessage.fromComponent(ichatmutablecomponent));
-+        } else {
+         } else {
+-            return this.players.size() >= this.maxPlayers && !this.canBypassPlayerLimit(profile) ? Component.translatable("multiplayer.disconnect.server_full") : null;
 +            // return this.players.size() >= this.maxPlayers && !this.canBypassPlayerLimit(gameprofile) ? IChatBaseComponent.translatable("multiplayer.disconnect.server_full") : null;
 +            if (this.players.size() >= this.maxPlayers && !this.canBypassPlayerLimit(gameprofile)) {
 +                event.disallow(PlayerLoginEvent.Result.KICK_FULL, org.spigotmc.SpigotConfig.serverFullMessage); // Spigot
@@ -574,7 +573,7 @@
  
          while (iterator.hasNext()) {
              String s = (String) iterator.next();
-@@ -462,41 +662,81 @@
+@@ -462,41 +662,86 @@
              entityplayer1.addTag(s);
          }
  
@@ -587,6 +586,11 @@
 +        } else {
 +            teleporttransition = new TeleportTransition(((CraftWorld) location.getWorld()).getHandle(), CraftLocation.toVec3D(location), Vec3.ZERO, location.getYaw(), location.getPitch(), TeleportTransition.DO_NOTHING);
 +        }
++        // Spigot Start
++        if (teleporttransition == null) {
++            return entityplayer;
++        }
++        // Spigot End
 +        ServerLevel worldserver = teleporttransition.newLevel();
 +        entityplayer1.spawnIn(worldserver);
 +        entityplayer1.unsetRemoved();
@@ -664,7 +668,7 @@
          return entityplayer1;
      }
  
-@@ -524,7 +764,18 @@
+@@ -524,7 +769,18 @@
  
      public void tick() {
          if (++this.sendAllPlayerInfoIn > 600) {
@@ -684,7 +688,7 @@
              this.sendAllPlayerInfoIn = 0;
          }
  
-@@ -541,6 +792,25 @@
+@@ -541,6 +797,25 @@
  
      }
  
@@ -710,7 +714,7 @@
      public void broadcastAll(Packet<?> packet, ResourceKey<Level> dimension) {
          Iterator iterator = this.players.iterator();
  
-@@ -554,7 +824,7 @@
+@@ -554,7 +829,7 @@
  
      }
  
@@ -719,7 +723,7 @@
          PlayerTeam scoreboardteam = source.getTeam();
  
          if (scoreboardteam != null) {
-@@ -573,7 +843,7 @@
+@@ -573,7 +848,7 @@
          }
      }
  
@@ -728,7 +732,7 @@
          PlayerTeam scoreboardteam = source.getTeam();
  
          if (scoreboardteam == null) {
-@@ -619,7 +889,7 @@
+@@ -619,7 +894,7 @@
      }
  
      public void deop(GameProfile profile) {
@@ -737,7 +741,7 @@
          ServerPlayer entityplayer = this.getPlayer(profile.getId());
  
          if (entityplayer != null) {
-@@ -643,6 +913,7 @@
+@@ -643,6 +918,7 @@
              player.connection.send(new ClientboundEntityEventPacket(player, b0));
          }
  
@@ -745,7 +749,7 @@
          this.server.getCommands().sendCommands(player);
      }
  
-@@ -669,10 +940,16 @@
+@@ -669,10 +945,16 @@
          return null;
      }
  
@@ -763,7 +767,7 @@
              if (entityplayer != player && entityplayer.level().dimension() == worldKey) {
                  double d4 = x - entityplayer.getX();
                  double d5 = y - entityplayer.getY();
-@@ -712,15 +989,19 @@
+@@ -712,15 +994,19 @@
      public void reloadWhiteList() {}
  
      public void sendLevelInfo(ServerPlayer player, ServerLevel world) {
@@ -787,7 +791,7 @@
          }
  
          player.connection.send(new ClientboundGameEventPacket(ClientboundGameEventPacket.LEVEL_CHUNKS_LOAD_START, 0.0F));
-@@ -729,8 +1010,16 @@
+@@ -729,8 +1015,16 @@
  
      public void sendAllPlayerInfo(ServerPlayer player) {
          player.inventoryMenu.sendAllDataToRemote();
@@ -805,7 +809,7 @@
      }
  
      public int getPlayerCount() {
-@@ -786,12 +1075,22 @@
+@@ -786,12 +1080,22 @@
      }
  
      public void removeAll() {
@@ -830,7 +834,7 @@
      public void broadcastSystemMessage(Component message, boolean overlay) {
          this.broadcastSystemMessage(message, (entityplayer) -> {
              return message;
-@@ -849,16 +1148,23 @@
+@@ -849,16 +1153,23 @@
          return message.hasSignature() && !message.hasExpiredServer(Instant.now());
      }
  
@@ -858,7 +862,7 @@
                  Path path = file2.toPath();
  
                  if (FileUtil.isPathNormalized(path) && FileUtil.isPathPortable(path) && path.startsWith(file.getPath()) && file2.isFile()) {
-@@ -867,7 +1173,7 @@
+@@ -867,7 +1178,7 @@
              }
  
              serverstatisticmanager = new ServerStatsCounter(this.server, file1);
@@ -867,7 +871,7 @@
          }
  
          return serverstatisticmanager;
-@@ -875,13 +1181,13 @@
+@@ -875,13 +1186,13 @@
  
      public PlayerAdvancements getPlayerAdvancements(ServerPlayer player) {
          UUID uuid = player.getUUID();
@@ -883,7 +887,7 @@
          }
  
          advancementdataplayer.setPlayer(player);
-@@ -932,15 +1238,28 @@
+@@ -932,15 +1243,28 @@
      }
  
      public void reloadResources() {