PaperMC/paper-server/patches/sources/net/minecraft/server/commands/TeleportCommand.java.patch

--- a/net/minecraft/server/commands/TeleportCommand.java
+++ b/net/minecraft/server/commands/TeleportCommand.java
@@ -22,6 +22,7 @@
 import net.minecraft.core.BlockPos;
 import net.minecraft.network.chat.Component;
 import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.util.Mth;
 import net.minecraft.world.entity.Entity;
 import net.minecraft.world.entity.LivingEntity;
@@ -30,6 +31,11 @@
 import net.minecraft.world.level.Level;
 import net.minecraft.world.phys.Vec2;
 import net.minecraft.world.phys.Vec3;
+import org.bukkit.Location;
+import org.bukkit.craftbukkit.CraftWorld;
+import org.bukkit.event.entity.EntityTeleportEvent;
+import org.bukkit.event.player.PlayerTeleportEvent;
+// CraftBukkit end
 
 public class TeleportCommand {
 
@@ -167,7 +173,30 @@
             float f4 = Mth.wrapDegrees(f2);
             float f5 = Mth.wrapDegrees(f3);
 
-            if (target.teleportTo(world, d3, d4, d5, movementFlags, f4, f5, true)) {
+            // CraftBukkit start - Teleport event
+            boolean result;
+            if (target instanceof ServerPlayer player) {
+                result = player.teleportTo(world, d3, d4, d5, movementFlags, f4, f5, true, PlayerTeleportEvent.TeleportCause.COMMAND);
+            } else {
+                Location to = new Location(world.getWorld(), d3, d4, d5, f4, f5);
+                EntityTeleportEvent event = new EntityTeleportEvent(target.getBukkitEntity(), target.getBukkitEntity().getLocation(), to);
+                world.getCraftServer().getPluginManager().callEvent(event);
+                if (event.isCancelled()) {
+                    return;
+                }
+
+                d3 = to.getX();
+                d4 = to.getY();
+                d5 = to.getZ();
+                f4 = to.getYaw();
+                f5 = to.getPitch();
+                world = ((CraftWorld) to.getWorld()).getHandle();
+
+                result = target.teleportTo(world, d3, d4, d5, movementFlags, f4, f5, true);
+            }
+
+            if (result) {
+                // CraftBukkit end
                 if (facingLocation != null) {
                     facingLocation.perform(source, target);
                 }