craftbukkit/nms-patches/net/minecraft/world/entity/npc/InventoryCarrier.patch

--- a/net/minecraft/world/entity/npc/InventoryCarrier.java
+++ b/net/minecraft/world/entity/npc/InventoryCarrier.java
@@ -8,6 +8,10 @@
 import net.minecraft.world.level.storage.ValueInput;
 import net.minecraft.world.level.storage.ValueOutput;
 
+// CraftBukkit start
+import org.bukkit.event.entity.EntityRemoveEvent;
+// CraftBukkit end
+
 public interface InventoryCarrier {
 
     String TAG_INVENTORY = "Inventory";
@@ -25,13 +29,20 @@
                 return;
             }
 
+            // CraftBukkit start
+            ItemStack remaining = new InventorySubcontainer(inventorysubcontainer).addItem(itemstack);
+            if (org.bukkit.craftbukkit.event.CraftEventFactory.callEntityPickupItemEvent(entityinsentient, entityitem, remaining.getCount(), false).isCancelled()) {
+                return;
+            }
+            // CraftBukkit end
+
             entityinsentient.onItemPickup(entityitem);
             int i = itemstack.getCount();
             ItemStack itemstack1 = inventorysubcontainer.addItem(itemstack);
 
             entityinsentient.take(entityitem, i - itemstack1.getCount());
             if (itemstack1.isEmpty()) {
-                entityitem.discard();
+                entityitem.discard(EntityRemoveEvent.Cause.PICKUP); // CraftBukkit - add Bukkit remove cause
             } else {
                 itemstack.setCount(itemstack1.getCount());
             }