From 8acab4479751258691fdaa1cdb4fdc524a21c368 Mon Sep 17 00:00:00 2001
From: MidnightTale <mntale@pm.me>
Date: Mon, 3 Aug 2026 16:46:04 +0700
Subject: [PATCH] fix: detect vertical falling blocks entering end portals

---
 .gitignore                                    |  1 +
 .../foliaflow/watcher/PortalWatcher.java      | 57 +++++++++++++------
 2 files changed, 42 insertions(+), 16 deletions(-)

diff --git a/.gitignore b/.gitignore
index 3c37caf..cdb5be5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -116,3 +116,4 @@ run/
 
 # Avoid ignoring Gradle wrapper jar file (.jar files are usually ignored)
 !gradle-wrapper.jar
+niri-rpc/
diff --git a/src/main/java/xyz/hynse/foliaflow/watcher/PortalWatcher.java b/src/main/java/xyz/hynse/foliaflow/watcher/PortalWatcher.java
index 22d26ec..581b07b 100644
--- a/src/main/java/xyz/hynse/foliaflow/watcher/PortalWatcher.java
+++ b/src/main/java/xyz/hynse/foliaflow/watcher/PortalWatcher.java
@@ -9,6 +9,7 @@ import org.bukkit.entity.FallingBlock;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
 import org.bukkit.event.entity.EntityChangeBlockEvent;
+import org.bukkit.event.entity.EntityPortalEnterEvent;
 import org.bukkit.util.Vector;
 
 import xyz.hynse.foliaflow.FoliaFlow;
@@ -18,31 +19,55 @@ import static xyz.hynse.foliaflow.util.VelocityUtil.getBlockMovingTo;
 
 public class PortalWatcher implements Listener {
 
+    private static final String DUPE_TAG = "foliaflow_dupe";
+
     @EventHandler
     public void onFallingBlockToBlock(EntityChangeBlockEvent e){
         if(e.getEntityType() != EntityType.FALLING_BLOCK) return;
         Entity entity = e.getEntity();
+        if(entity.getScoreboardTags().contains(DUPE_TAG)) return;
         Location loc = entity.getLocation();
         Vector vel = entity.getVelocity();
         Block movingTo = getBlockMovingTo(loc, vel);
 
         if(movingTo.getType() == Material.END_PORTAL){
-            Location spawnLoc = movingTo.getLocation();
-            spawnLoc.add(0.5, FoliaFlow.spawnHeight, 0.5);
-
-            FallingBlock dummy = loc.getWorld().spawnFallingBlock(spawnLoc, ((FallingBlock) entity).getBlockData());
-            Vector dummyVel = vel.clone();
-            dummyVel.multiply(FoliaFlow.horizontalCoefficient);
-            dummyVel.setY(vel.getY() * FoliaFlow.verticalCoefficient);
-            dummy.setVelocity(dummyVel);
-
-            SchedulerUtil.runLaterEntity(dummy, FoliaFlow.instance, () -> {
-                        // Portal teleportation is a bit below vanilla, so we teleport it above
-                        dummy.teleportAsync(dummy.getLocation().add(0, FoliaFlow.TeleportOffset, 0));
-                        dummy.setVelocity(dummyVel);
-                    },
-                    2
-            );
+            spawnDupe(entity, movingTo, false);
         }
     }
+
+    @EventHandler
+    public void onPortalEnter(EntityPortalEnterEvent e){
+        if(e.getEntityType() != EntityType.FALLING_BLOCK) return;
+        Entity entity = e.getEntity();
+        if(entity.getScoreboardTags().contains(DUPE_TAG)) return;
+        Block portal = e.getLocation().getBlock();
+
+        if(portal.getType() == Material.END_PORTAL && portal.getRelative(0, -1, 0).getType().name().endsWith("_FENCE")){
+            spawnDupe(entity, portal, true);
+        }
+    }
+
+    private void spawnDupe(Entity entity, Block portal, boolean passThrough){
+        Location spawnLoc = portal.getLocation();
+        spawnLoc.add(0.5, FoliaFlow.spawnHeight, 0.5);
+
+        FallingBlock dummy = entity.getWorld().spawnFallingBlock(spawnLoc, ((FallingBlock) entity).getBlockData());
+        dummy.addScoreboardTag(DUPE_TAG);
+        Vector dummyVel = entity.getVelocity().clone();
+        dummyVel.multiply(FoliaFlow.horizontalCoefficient);
+        if(passThrough){
+            dummyVel.setY(entity.getVelocity().getY());
+        } else {
+            dummyVel.setY(entity.getVelocity().getY() * FoliaFlow.verticalCoefficient);
+        }
+        dummy.setVelocity(dummyVel);
+
+        SchedulerUtil.runLaterEntity(dummy, FoliaFlow.instance, () -> {
+                    // Portal teleportation is a bit below vanilla, so we teleport it above
+                    dummy.teleportAsync(dummy.getLocation().add(0, FoliaFlow.TeleportOffset, 0));
+                    dummy.setVelocity(dummyVel);
+                },
+                2
+        );
+    }
 }