added a config-entry to selectively ignore causes of the back-in-listener

Essentials/src/main/java/com/earth2me/essentials/EssentialsPlayerListener.java

@@ -695,6 +695,22 @@ public void onPlayerKickBanned(final AsyncPlayerPreLoginEvent event) {
         }
     }
 
+    private boolean isTeleportListenerIgnored() {
+        List<List<String>> ignoreList = ess.getSettings().getBackInListenerIgnoreList();
+
+        if (ignoreList.isEmpty())
+            return false;
+
+        for (StackTraceElement stackElement : Thread.currentThread().getStackTrace()) {
+            String representation = (stackElement.getClassName() + "#" + stackElement.getMethodName()).toLowerCase();
+
+            if (ignoreList.stream().anyMatch(keywords -> keywords.stream().allMatch(representation::contains)))
+                return true;
+        }
+
+        return false;
+    }
+
     @EventHandler(priority = EventPriority.HIGH, ignoreCancelled = true)
     public void onPlayerTeleport(final PlayerTeleportEvent event) {
         final Player player = event.getPlayer();
@@ -703,7 +719,8 @@ public void onPlayerTeleport(final PlayerTeleportEvent event) {
         }
         final User user = ess.getUser(player);
         if (ess.getSettings().registerBackInListener() && user.isAuthorized("essentials.back.onteleport")) {
-            user.setLastLocation();
+            if (!isTeleportListenerIgnored())
+                user.setLastLocation();
         }
         if (ess.getSettings().isTeleportInvulnerability()) {
             user.enableInvulnerabilityAfterTeleport();

Essentials/src/main/java/com/earth2me/essentials/ISettings.java

@@ -258,6 +258,8 @@ public interface ISettings extends IConf {
 
     boolean registerBackInListener();
 
+    List<List<String>> getBackInListenerIgnoreList();
+
     boolean getDisableItemPickupWhileAfk();
 
     EventPriority getRespawnPriority();

Essentials/src/main/java/com/earth2me/essentials/Settings.java

@@ -115,6 +115,7 @@ public class Settings implements net.ess3.api.ISettings {
     private KeepInvPolicy bindingItemPolicy;
     private Set<String> noGodWorlds = new HashSet<>();
     private boolean registerBackInListener;
+    private List<List<String>> backInListenerIgnoreList = new ArrayList<>();
     private boolean disableItemPickupWhileAfk;
     private long teleportInvulnerabilityTime;
     private boolean teleportInvulnerability;
@@ -805,6 +806,7 @@ public void reloadConfig() {
         teleportInvulnerability = _isTeleportInvulnerability();
         disableItemPickupWhileAfk = _getDisableItemPickupWhileAfk();
         registerBackInListener = _registerBackInListener();
+        backInListenerIgnoreList = _getBackInListenerIgnoreList();
         cancelAfkOnInteract = _cancelAfkOnInteract();
         cancelAfkOnMove = _cancelAfkOnMove();
         getFreezeAfkPlayers = _getFreezeAfkPlayers();
@@ -1421,6 +1423,31 @@ public boolean registerBackInListener() {
         return registerBackInListener;
     }
 
+    @Override
+    public List<List<String>> getBackInListenerIgnoreList() {
+        return backInListenerIgnoreList;
+    }
+
+    private List<List<String>> _getBackInListenerIgnoreList() {
+        List<List<String>> ignoreList = new ArrayList<>();
+
+        for (String entry : config.getList("back-in-listener-ignore-list", String.class)) {
+            List<String> ignoreEntry = new ArrayList<>();
+
+            for (String keyword : entry.split(",")) {
+                keyword = keyword.trim();
+
+                if (!keyword.isEmpty())
+                    ignoreEntry.add(keyword.toLowerCase());
+            }
+
+            if (!ignoreEntry.isEmpty())
+                ignoreList.add(ignoreEntry);
+        }
+
+        return ignoreList;
+    }
+
     @Override
     public int getMaxTreeCommandRange() {
         return config.getInt("tree-command-range-limit", 300);

Essentials/src/main/resources/config.yml

@@ -647,6 +647,12 @@ tree-command-range-limit: 300
 # If you set this to true, any plugin that uses teleport will have the previous location registered.
 register-back-in-listener: false
 
+# If some events of a teleportation are to be ignored selectively, they can be described as an entry of this list.
+# For example, the elevators of CraftBook would be "com.sk89q.craftbook.mechanics.Elevator#teleportPlayer".
+# Each entry down below can be made up of comma-separated and case-insensitive keywords, for abbreviation and generality.
+# Thus, "craftbook,elevator" would suffice to match the fully-qualified name mentioned above.
+back-in-listener-ignore-list: []
+
 # The delay, in seconds, before people can cause attack damage after logging in.
 # This prevents players from exploiting the temporary invulnerability they receive upon joining.
 login-attack-delay: 5