From 22f28c098ce3f53e750ea31f0d035da095d649b7 Mon Sep 17 00:00:00 2001
From: Sollace <sollacea@gmail.com>
Date: Mon, 12 Sep 2022 19:53:02 +0200
Subject: [PATCH] Fix duplication bug when equipping/unequipping spells

---
 .../unicopia/entity/player/PlayerCharmTracker.java |  2 +-
 .../minelittlepony/unicopia/item/GemstoneItem.java | 14 ++++++++++++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/main/java/com/minelittlepony/unicopia/entity/player/PlayerCharmTracker.java b/src/main/java/com/minelittlepony/unicopia/entity/player/PlayerCharmTracker.java
index c553dc7d..5f564c15 100644
--- a/src/main/java/com/minelittlepony/unicopia/entity/player/PlayerCharmTracker.java
+++ b/src/main/java/com/minelittlepony/unicopia/entity/player/PlayerCharmTracker.java
@@ -55,7 +55,7 @@ public class PlayerCharmTracker implements Tickable, NbtSerialisable {
     }
 
     public CustomisedSpellType<?> getEquippedSpell(Hand hand) {
-        return handSpells[hand.ordinal()];
+        return handSpells[hand.ordinal()] == null ? SpellType.EMPTY_KEY.withTraits() : handSpells[hand.ordinal()];
     }
 
     public TypedActionResult<CustomisedSpellType<?>> getSpellInHand(Hand hand) {
diff --git a/src/main/java/com/minelittlepony/unicopia/item/GemstoneItem.java b/src/main/java/com/minelittlepony/unicopia/item/GemstoneItem.java
index 6c59f578..3fef3ea8 100644
--- a/src/main/java/com/minelittlepony/unicopia/item/GemstoneItem.java
+++ b/src/main/java/com/minelittlepony/unicopia/item/GemstoneItem.java
@@ -47,13 +47,23 @@ public class GemstoneItem extends Item {
 
             CustomisedSpellType<?> existing = charms.getEquippedSpell(hand);
 
-            if (existing != null) {
-                stack = existing.traits().applyTo(enchant(stack, existing.type()));
+            if (!existing.isEmpty()) {
+
+                if (stack.getCount() == 1) {
+                    stack = existing.traits().applyTo(enchant(stack, existing.type()));
+                } else {
+                    user.giveItemStack(existing.traits().applyTo(enchant(stack.split(1), existing.type())));
+                }
             }
 
             if (spell.getResult().isAccepted()) {
                 charms.equipSpell(hand, spell.getValue());
             } else {
+
+                if (existing.isEmpty()) {
+                    return result;
+                }
+
                 charms.equipSpell(hand, SpellType.EMPTY_KEY.withTraits());
             }
             return TypedActionResult.success(stack, true);