From c47f1f572c3b46b197e91533843e4618ddc3a94f Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Wed, 27 Sep 2017 10:55:50 +0100
Subject: [PATCH] Added API method Item->pop()

---
 src/pocketmine/block/FlowerPot.php           |  8 +-------
 src/pocketmine/block/ItemFrame.php           | 12 ++----------
 src/pocketmine/inventory/ShapelessRecipe.php |  8 ++------
 src/pocketmine/item/Item.php                 | 19 +++++++++++++++++++
 src/pocketmine/level/Level.php               |  5 +----
 src/pocketmine/tile/Furnace.php              | 10 ++--------
 6 files changed, 27 insertions(+), 35 deletions(-)

diff --git a/src/pocketmine/block/FlowerPot.php b/src/pocketmine/block/FlowerPot.php
index d7e6f771f..ef26b73fb 100644
--- a/src/pocketmine/block/FlowerPot.php
+++ b/src/pocketmine/block/FlowerPot.php
@@ -112,14 +112,8 @@ class FlowerPot extends Flowable{
 
 		$this->setDamage(self::STATE_FULL); //specific damage value is unnecessary, it just needs to be non-zero to show an item.
 		$this->getLevel()->setBlock($this, $this, true, false);
-		$pot->setItem($item);
+		$pot->setItem($item->pop());
 
-		if($player instanceof Player){
-			if($player->isSurvival()){
-				$item->setCount($item->getCount() - 1);
-				$player->getInventory()->setItemInHand($item->getCount() > 0 ? $item : ItemFactory::get(Item::AIR));
-			}
-		}
 		return true;
 	}
 
diff --git a/src/pocketmine/block/ItemFrame.php b/src/pocketmine/block/ItemFrame.php
index 23e8fc7f2..6c6f3195e 100644
--- a/src/pocketmine/block/ItemFrame.php
+++ b/src/pocketmine/block/ItemFrame.php
@@ -63,16 +63,8 @@ class ItemFrame extends Flowable{
 
 		if($tile->hasItem()){
 			$tile->setItemRotation(($tile->getItemRotation() + 1) % 8);
-		}else{
-			if($item->getCount() > 0){
-				$frameItem = clone $item;
-				$frameItem->setCount(1);
-				$item->setCount($item->getCount() - 1);
-				$tile->setItem($frameItem);
-				if($player instanceof Player and $player->isSurvival()){
-					$player->getInventory()->setItemInHand($item->getCount() <= 0 ? ItemFactory::get(Item::AIR) : $item);
-				}
-			}
+		}elseif(!$item->isNull()){
+			$tile->setItem($item->pop());
 		}
 
 		return true;
diff --git a/src/pocketmine/inventory/ShapelessRecipe.php b/src/pocketmine/inventory/ShapelessRecipe.php
index b33445d52..99034fc78 100644
--- a/src/pocketmine/inventory/ShapelessRecipe.php
+++ b/src/pocketmine/inventory/ShapelessRecipe.php
@@ -82,12 +82,8 @@ class ShapelessRecipe implements CraftingRecipe{
 			throw new \InvalidArgumentException("Shapeless recipes cannot have more than 9 ingredients");
 		}
 
-		$it = clone $item;
-		$it->setCount(1);
-
 		while($item->getCount() > 0){
-			$this->ingredients[] = clone $it;
-			$item->setCount($item->getCount() - 1);
+			$this->ingredients[] = $item->pop();
 		}
 
 		return $this;
@@ -105,7 +101,7 @@ class ShapelessRecipe implements CraftingRecipe{
 			}
 			if($ingredient->equals($item, !$item->hasAnyDamageValue(), $item->hasCompoundTag())){
 				unset($this->ingredients[$index]);
-				$item->setCount($item->getCount() - 1);
+				$item->pop();
 			}
 		}
 
diff --git a/src/pocketmine/item/Item.php b/src/pocketmine/item/Item.php
index 25d881c33..7759a2860 100644
--- a/src/pocketmine/item/Item.php
+++ b/src/pocketmine/item/Item.php
@@ -643,6 +643,25 @@ class Item implements ItemIds, \JsonSerializable{
 		return $this;
 	}
 
+	/**
+	 * Pops an item from the stack and returns it, decreasing the stack count of this item stack by one.
+	 * @return Item
+	 *
+	 * @throws \InvalidStateException if the count is less than or equal to zero, or if the stack is air.
+	 */
+	public function pop() : Item{
+		if($this->isNull()){
+			throw new \InvalidStateException("Cannot pop an item from a null stack");
+		}
+
+		$item = clone $this;
+		$item->setCount(1);
+
+		$this->count--;
+
+		return $item;
+	}
+
 	public function isNull() : bool{
 		return $this->count <= 0 or $this->id === Item::AIR;
 	}
diff --git a/src/pocketmine/level/Level.php b/src/pocketmine/level/Level.php
index 0268d83f8..bce059ee0 100644
--- a/src/pocketmine/level/Level.php
+++ b/src/pocketmine/level/Level.php
@@ -1823,10 +1823,7 @@ class Level implements ChunkManager, Metadatable{
 			$this->broadcastLevelSoundEvent($hand, LevelSoundEventPacket::SOUND_PLACE, 1, $hand->getId());
 		}
 
-		$item->setCount($item->getCount() - 1);
-		if($item->getCount() <= 0){
-			$item = ItemFactory::get(Item::AIR, 0, 0);
-		}
+		$item->pop();
 
 		return true;
 	}
diff --git a/src/pocketmine/tile/Furnace.php b/src/pocketmine/tile/Furnace.php
index 8c130d27d..54725edda 100644
--- a/src/pocketmine/tile/Furnace.php
+++ b/src/pocketmine/tile/Furnace.php
@@ -201,10 +201,7 @@ class Furnace extends Spawnable implements InventoryHolder, Container, Nameable{
 		}
 
 		if($this->namedtag->BurnTime->getValue() > 0 and $ev->isBurning()){
-			$fuel->setCount($fuel->getCount() - 1);
-			if($fuel->getCount() === 0){
-				$fuel = ItemFactory::get(Item::AIR, 0, 0);
-			}
+			$fuel->pop();
 			$this->inventory->setFuel($fuel);
 		}
 	}
@@ -241,10 +238,7 @@ class Furnace extends Spawnable implements InventoryHolder, Container, Nameable{
 
 					if(!$ev->isCancelled()){
 						$this->inventory->setResult($ev->getResult());
-						$raw->setCount($raw->getCount() - 1);
-						if($raw->getCount() === 0){
-							$raw = ItemFactory::get(Item::AIR, 0, 0);
-						}
+						$raw->pop();
 						$this->inventory->setSmelting($raw);
 					}