From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Wed, 22 May 2024 10:01:19 -0700
Subject: [PATCH] Fix equipment slot and group API

Add test for EquipmentSlotGroup

diff --git a/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java b/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java
index 87bb193acd39515c2d80cf1ab41d1e2538112fe9..a39785b4e45e7bf57d6c60abae0771a629148342 100644
--- a/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java
+++ b/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java
@@ -1331,7 +1331,7 @@ class CraftMetaItem implements ItemMeta, Damageable, Repairable, BlockDataMeta {
         this.checkAttributeList();
         SetMultimap<Attribute, AttributeModifier> result = LinkedHashMultimap.create();
         for (Map.Entry<Attribute, AttributeModifier> entry : this.attributeModifiers.entries()) {
-            if (entry.getValue().getSlot() == null || entry.getValue().getSlot() == slot) {
+            if (entry.getValue().getSlotGroup().test(slot)) { // Paper - correctly test slot against group
                 result.put(entry.getKey(), entry.getValue());
             }
         }
@@ -1392,9 +1392,7 @@ class CraftMetaItem implements ItemMeta, Damageable, Repairable, BlockDataMeta {
 
         while (iter.hasNext()) {
             Map.Entry<Attribute, AttributeModifier> entry = iter.next();
-            // Explicitly match against null because (as of MC 1.13) AttributeModifiers without a -
-            // set slot are active in any slot.
-            if (entry.getValue().getSlot() == null || entry.getValue().getSlot() == slot) {
+            if (entry.getValue().getSlotGroup().test(slot)) { // Paper - correctly test slot against group
                 iter.remove();
                 ++removed;
             }
diff --git a/src/test/java/io/papermc/paper/inventory/item/EquipmentSlotGroupTest.java b/src/test/java/io/papermc/paper/inventory/item/EquipmentSlotGroupTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..ee0bfe4edb134d7ea3a3b97f5102a7f3122c3b99
--- /dev/null
+++ b/src/test/java/io/papermc/paper/inventory/item/EquipmentSlotGroupTest.java
@@ -0,0 +1,51 @@
+package io.papermc.paper.inventory.item;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.util.ArrayList;
+import java.util.List;
+import net.minecraft.world.entity.EquipmentSlot;
+import org.bukkit.craftbukkit.CraftEquipmentSlot;
+import org.bukkit.inventory.EquipmentSlotGroup;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.EnumSource;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+class EquipmentSlotGroupTest {
+
+    static List<EquipmentSlotGroup> apiValues() throws ReflectiveOperationException {
+        final List<EquipmentSlotGroup> apiValues = new ArrayList<>();
+        for (final Field field : EquipmentSlotGroup.class.getDeclaredFields()) {
+            if (!Modifier.isStatic(field.getModifiers()) || !Modifier.isFinal(field.getModifiers()) || !field.getType().equals(EquipmentSlotGroup.class)) {
+                continue;
+            }
+            apiValues.add((EquipmentSlotGroup) field.get(null));
+        }
+        if (apiValues.isEmpty()) {
+            throw new RuntimeException("Didn't find any api " + EquipmentSlotGroup.class.getSimpleName());
+        }
+        return apiValues;
+    }
+
+    @ParameterizedTest
+    @MethodSource("apiValues")
+    void testBukkitToNms(final EquipmentSlotGroup slotGroup) {
+        final net.minecraft.world.entity.EquipmentSlotGroup nmsGroup = CraftEquipmentSlot.getNMSGroup(slotGroup);
+        assertNotNull(nmsGroup, "No nms slot group found for " + slotGroup);
+        assertEquals(nmsGroup.getSerializedName(), slotGroup.toString(), "slot group name mismatch");
+        for (final EquipmentSlot slot : EquipmentSlot.values()) {
+            assertEquals(nmsGroup.test(slot), slotGroup.test(CraftEquipmentSlot.getSlot(slot)));
+        }
+    }
+
+    @ParameterizedTest
+    @EnumSource(net.minecraft.world.entity.EquipmentSlotGroup.class)
+    void testNmsToBukkit(final net.minecraft.world.entity.EquipmentSlotGroup slotGroup) {
+        final EquipmentSlotGroup apiGroup = CraftEquipmentSlot.getSlot(slotGroup);
+        assertNotNull(apiGroup, "No api slot group found for " + slotGroup);
+        assertEquals(apiGroup.toString(), slotGroup.getSerializedName(), "slot group name mismatch");
+    }
+}