PaperMC/paper-server/patches/sources/net/minecraft/world/entity/Leashable.java.patch

--- a/net/minecraft/world/entity/Leashable.java
+++ b/net/minecraft/world/entity/Leashable.java
@@ -15,6 +15,10 @@
 import net.minecraft.world.level.GameRules;
 import net.minecraft.world.level.ItemLike;
 import net.minecraft.world.level.Level;
+// CraftBukkit start
+import org.bukkit.event.entity.EntityUnleashEvent;
+import org.bukkit.event.entity.EntityUnleashEvent.UnleashReason;
+// CraftBukkit end
 
 public interface Leashable {
 
@@ -45,7 +49,7 @@
 
     default void setDelayedLeashHolderId(int unresolvedLeashHolderId) {
         this.setLeashData(new Leashable.LeashData(unresolvedLeashHolderId));
-        Leashable.dropLeash((Entity) this, false, false);
+        Leashable.dropLeash((Entity & Leashable) this, false, false); // CraftBukkit - decompile error
     }
 
     default void readLeashData(CompoundTag nbt) {
@@ -64,7 +68,7 @@
             return new Leashable.LeashData(Either.left(nbt.getCompound("leash").getUUID("UUID")));
         } else {
             if (nbt.contains("leash", 11)) {
-                Either<UUID, BlockPos> either = (Either) NbtUtils.readBlockPos(nbt, "leash").map(Either::right).orElse((Object) null);
+                Either<UUID, BlockPos> either = (Either) NbtUtils.readBlockPos(nbt, "leash").map(Either::right).orElse(null); // CraftBukkit - decompile error
 
                 if (either != null) {
                     return new Leashable.LeashData(either);
@@ -79,6 +83,11 @@
         if (leashData != null) {
             Either<UUID, BlockPos> either = leashData.delayedLeashInfo;
             Entity entity = leashData.leashHolder;
+            // CraftBukkit start - SPIGOT-7487: Don't save (and possible drop) leash, when the holder was removed by a plugin
+            if (entity != null && entity.pluginRemoved) {
+                return;
+            }
+            // CraftBukkit end
 
             if (entity instanceof LeashFenceKnotEntity) {
                 LeashFenceKnotEntity entityleash = (LeashFenceKnotEntity) entity;
@@ -121,7 +130,9 @@
                 }
 
                 if (entity.tickCount > 100) {
+                    entity.forceDrops = true; // CraftBukkit
                     entity.spawnAtLocation(worldserver, (ItemLike) Items.LEAD);
+                    entity.forceDrops = false; // CraftBukkit
                     ((Leashable) entity).setLeashData((Leashable.LeashData) null);
                 }
             }
@@ -130,11 +141,11 @@
     }
 
     default void dropLeash() {
-        Leashable.dropLeash((Entity) this, true, true);
+        Leashable.dropLeash((Entity & Leashable) this, true, true); // CraftBukkit - decompile error
     }
 
     default void removeLeash() {
-        Leashable.dropLeash((Entity) this, true, false);
+        Leashable.dropLeash((Entity & Leashable) this, true, false); // CraftBukkit - decompile error
     }
 
     default void onLeashRemoved() {}
@@ -151,7 +162,9 @@
                 ServerLevel worldserver = (ServerLevel) world;
 
                 if (dropItem) {
+                    entity.forceDrops = true; // CraftBukkit
                     entity.spawnAtLocation(worldserver, (ItemLike) Items.LEAD);
+                    entity.forceDrops = false; // CraftBukkit
                 }
 
                 if (sendPacket) {
@@ -171,7 +184,8 @@
 
         if (leashable_a != null && leashable_a.leashHolder != null) {
             if (!entity.isAlive() || !leashable_a.leashHolder.isAlive()) {
-                if (world.getGameRules().getBoolean(GameRules.RULE_DOENTITYDROPS)) {
+                world.getCraftServer().getPluginManager().callEvent(new EntityUnleashEvent(entity.getBukkitEntity(), (!entity.isAlive()) ? UnleashReason.PLAYER_UNLEASH : UnleashReason.HOLDER_GONE)); // CraftBukkit
+                if (world.getGameRules().getBoolean(GameRules.RULE_DOENTITYDROPS) && !entity.pluginRemoved) { // CraftBukkit - SPIGOT-7487: Don't drop leash, when the holder was removed by a plugin
                     ((Leashable) entity).dropLeash();
                 } else {
                     ((Leashable) entity).removeLeash();
@@ -205,13 +219,18 @@
     }
 
     default void leashTooFarBehaviour() {
+        // CraftBukkit start
+        if (this instanceof Entity entity) {
+            entity.level().getCraftServer().getPluginManager().callEvent(new EntityUnleashEvent(entity.getBukkitEntity(), EntityUnleashEvent.UnleashReason.DISTANCE));
+        }
+        // CraftBukkit end
         this.dropLeash();
     }
 
     default void closeRangeLeashBehaviour(Entity entity) {}
 
     default void elasticRangeLeashBehaviour(Entity leashHolder, float distance) {
-        Leashable.legacyElasticRangeLeashBehaviour((Entity) this, leashHolder, distance);
+        Leashable.legacyElasticRangeLeashBehaviour((Entity & Leashable) this, leashHolder, distance); // CraftBukkit - decompile error
     }
 
     private static <E extends Entity & Leashable> void legacyElasticRangeLeashBehaviour(E entity, Entity leashHolder, float distance) {
@@ -223,7 +242,7 @@
     }
 
     default void setLeashedTo(Entity leashHolder, boolean sendPacket) {
-        this.setLeashedTo((Entity) this, leashHolder, sendPacket);
+        Leashable.setLeashedTo((Entity & Leashable) this, leashHolder, sendPacket); // CraftBukkit - decompile error
     }
 
     private static <E extends Entity & Leashable> void setLeashedTo(E entity, Entity leashHolder, boolean sendPacket) {
@@ -254,7 +273,7 @@
 
     @Nullable
     default Entity getLeashHolder() {
-        return Leashable.getLeashHolder((Entity) this);
+        return Leashable.getLeashHolder((Entity & Leashable) this); // CraftBukkit - decompile error
     }
 
     @Nullable