SPIGOT-4556: Fix plugins closing inventory during drop events

nms-patches/Container.patch

@@ -126,7 +126,20 @@
                      }
                  }
              } else if (inventoryclicktype == InventoryClickType.SWAP && j >= 0 && j < 9) {
-@@ -565,6 +637,7 @@
+@@ -356,8 +428,11 @@
+         PlayerInventory playerinventory = entityhuman.inventory;
+ 
+         if (!playerinventory.getCarried().isEmpty()) {
+-            entityhuman.drop(playerinventory.getCarried(), false);
++            // CraftBukkit start - SPIGOT-4556
++            ItemStack carried = playerinventory.getCarried();
+             playerinventory.setCarried(ItemStack.a);
++            entityhuman.drop(carried, false);
++            // CraftBukkit end
+         }
+ 
+     }
+@@ -565,6 +640,7 @@
              if (inventorycraftresult.a(world, entityplayer, irecipe) && irecipe != null) {
                  itemstack = irecipe.craftItem(iinventory);
              }