Spigot Fix (https://github.com/PaperSpigot/Paper-1.7/blob/master/CraftBukkit-Patches/0170-Remove-uneeded-validation.patch)

src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java

@@ -388,7 +388,7 @@ class CraftMetaItem implements ItemMeta, Repairable {
     }
 
     static void applyEnchantments(Map<Enchantment, Integer> enchantments, net.minecraft.nbt.NBTTagCompound tag, ItemMetaKey key) {
-        if (enchantments == null || enchantments.size() == 0) {
+        if (enchantments == null || /*enchantments.size() == 0*/) { // Spigot - remove size check
             return;
         }
 
@@ -479,7 +479,14 @@ class CraftMetaItem implements ItemMeta, Repairable {
     }
 
     public boolean removeEnchant(Enchantment ench) {
-        return hasEnchants() && enchantments.remove(ench) != null;
+        // Spigot start
+        boolean b = hasEnchants() && enchantments.remove( ench ) != null;
+        if ( enchantments != null && enchantments.isEmpty() )
+        {
+            this.enchantments = null;
+        }
+        return b;
+        // Spigot end
     }
 
     public boolean hasEnchants() {