Fixed crash with dispensers dispensing dispensables

src/main/java/net/minecraft/server/ItemStack.java

@@ -43,11 +43,13 @@ public final class ItemStack {
     public ItemStack(int id, int count, int data, NBTTagList enchantments) {
         this(id, count, data);
         // taken from .addEnchantment
+        if (Item.byId[this.id].getMaxStackSize() == 1) {
             if (this.tag == null) {
                 this.setTag(new NBTTagCompound());
             }
 
-        this.tag.set("ench", enchantments); // modify this part to use passed in enchantments list
+            this.tag.set("ench", enchantments.clone()); // modify this part to use passed in enchantments list
+        }
     }
     // CraftBukkit end