I'm attempting to empty the "contents" of an item by dropping them on the ground to eliminate the possibility of the contents being deleted due to a full inventory, but, whenever I attempt to do this, a ghost copy of the previously stored item is created in addition to the actual, collectible item. Is there any way to fix this?

 

Method (there are two uses of playerIn.entityDropItem()):

 public ItemStack onItemRightClick(ItemStack itemStackIn, World worldIn, EntityPlayer playerIn)
 {
	 if(itemStackIn.getItem() instanceof ItemInlayArmor)
	 {
		 int focusTarget = playerIn.inventory.currentItem + 1;
		 if(!playerIn.isSneaking())
		 {

			 if(itemStackIn.hasTagCompound())
			 {
				 if(playerIn.inventory.getStackInSlot(focusTarget) != null)
				 {
					 if(Item.getByNameOrId(itemStackIn.getTagCompound().getString("id")).equals(playerIn.inventory.getStackInSlot(focusTarget).getItem()))
					 {
						 return itemStackIn;
					 }
				 }
				 playerIn.entityDropItem(new ItemStack(Item.getByNameOrId(itemStackIn.getTagCompound().getString("id")), 1, itemStackIn.getTagCompound().getShort("Damage")), 0);
				 //playerIn.inventory.addItemStackToInventory(new ItemStack(Item.getByNameOrId(itemStackIn.getTagCompound().getString("id")), 1, itemStackIn.getTagCompound().getShort("Damage")));
				 itemStackIn.setTagCompound(null);
			 }
			 ItemInlayArmor item = (ItemInlayArmor)itemStackIn.getItem();

			 if(playerIn.inventory.getStackInSlot(focusTarget) != null)
			 {
				 ItemStack focusItem = playerIn.inventory.getStackInSlot(focusTarget);
				 if(validItems.contains(Item.itemRegistry.getNameForObject(focusItem.getItem()).toString()))
				 {
					 if(Item.itemRegistry.getNameForObject(focusItem.getItem()).toString().equals("minecraft:dye") && focusItem.getItemDamage() != 0)
					 {
						 return itemStackIn;
					 }
					playerIn.inventory.decrStackSize(focusTarget, 1);

					NBTTagCompound nbt = itemStackIn.getTagCompound();
					if(nbt == null)
				 	{
						nbt = new NBTTagCompound();
						itemStackIn.setTagCompound(nbt);
				 	}
					itemStackIn.loadItemStackFromNBT(focusItem.writeToNBT(nbt));
				 }
			 }

		 }
		 else if(itemStackIn.hasTagCompound())
		 {
			 playerIn.entityDropItem(new ItemStack(Item.getByNameOrId(itemStackIn.getTagCompound().getString("id")), 1, itemStackIn.getTagCompound().getShort("Damage")), 0);
			 //playerIn.inventory.addItemStackToInventory(new ItemStack(Item.getByNameOrId(itemStackIn.getTagCompound().getString("id")), 1, itemStackIn.getTagCompound().getShort("Damage")));
			 itemStackIn.setTagCompound(null);
			 return itemStackIn;
		 }
	 }
     return itemStackIn;
 }

 

I tried worldIn.updateEntities() without knowing its precise function, but, regardless, it had no effect.

You are dropping the items on the server side and the client side. Do a !world.isRemote check first.