SPIGOT-5504: cancelling InventoryMoveItemEvent on composter doesn't properly cancel

By: md_5 <git@md-5.net>

paper-server/nms-patches/BlockComposter.patch

@@ -42,7 +42,23 @@
          }
  
          @Override
-@@ -313,8 +317,9 @@
+@@ -306,15 +310,23 @@
+ 
+         @Override
+         public void update() {
+-            BlockComposter.d(this.a, this.b, this.c);
+-            this.d = true;
++            // CraftBukkit start - allow putting items back (eg cancelled InventoryMoveItemEvent)
++            if (this.isNotEmpty()) {
++                BlockComposter.d(this.a, this.b, this.c);
++                this.d = true;
++            } else {
++                this.b.setTypeAndData(this.c, this.a, 3);
++                this.d = false;
++            }
++            // CraftBukkit end
+         }
+     }
  
      static class ContainerEmpty extends InventorySubcontainer implements IWorldInventory {