handle BODY slot for non-mobs (#10822)

patches/api/Expand-ArmorStand-API.patch

@@ -182,6 +182,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +     *
 +     * @param slot the equipment slot to get
 +     * @return the ItemStack in the equipment slot
++     * @throws IllegalArgumentException if the slot is invalid for the entity
 +     */
 +    @NotNull
 +    ItemStack getItem(@NotNull final org.bukkit.inventory.EquipmentSlot slot);
@@ -192,6 +193,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +     *
 +     * @param slot the equipment slot to set
 +     * @param item the item to hold
++     * @throws IllegalArgumentException if the slot is invalid for the entity
 +     */
 +    void setItem(@NotNull final org.bukkit.inventory.EquipmentSlot slot, @Nullable final ItemStack item);
 +

patches/api/Fix-equipment-slot-and-group-API.patch

@@ -17,6 +17,36 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
      public EquipmentSlot getSlot() {
          return slot == EquipmentSlotGroup.ANY ? null : slot.getExample();
      }
+diff --git a/src/main/java/org/bukkit/inventory/EntityEquipment.java b/src/main/java/org/bukkit/inventory/EntityEquipment.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/inventory/EntityEquipment.java
++++ b/src/main/java/org/bukkit/inventory/EntityEquipment.java
+@@ -0,0 +0,0 @@ public interface EntityEquipment {
+      *
+      * @param slot the slot to put the ItemStack
+      * @param item the ItemStack to set
++     * @throws IllegalArgumentException if the slot is invalid for the entity
+      */
+     public void setItem(@NotNull EquipmentSlot slot, @Nullable ItemStack item);
+ 
+@@ -0,0 +0,0 @@ public interface EntityEquipment {
+      *
+      * @param slot the slot to put the ItemStack
+      * @param item the ItemStack to set
+-     * @param silent whether or not the equip sound should be silenced
++     * @param silent whether the equip sound should be silenced
++     * @throws IllegalArgumentException if the slot is invalid for the entity
+      */
+     public void setItem(@NotNull EquipmentSlot slot, @Nullable ItemStack item, boolean silent);
+ 
+@@ -0,0 +0,0 @@ public interface EntityEquipment {
+      *
+      * @param slot the slot to get the ItemStack
+      * @return the ItemStack in the given slot
++     * @throws IllegalArgumentException if the slot is invalid for the entity
+      */
+     @NotNull
+     public ItemStack getItem(@NotNull EquipmentSlot slot);
 diff --git a/src/main/java/org/bukkit/inventory/EquipmentSlotGroup.java b/src/main/java/org/bukkit/inventory/EquipmentSlotGroup.java
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
 --- a/src/main/java/org/bukkit/inventory/EquipmentSlotGroup.java

patches/server/Expand-ArmorStand-API.patch

@@ -23,13 +23,15 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
  
 +    @Override
 +    public ItemStack getItem(org.bukkit.inventory.EquipmentSlot slot) {
-+        com.google.common.base.Preconditions.checkNotNull(slot, "slot");
++        com.google.common.base.Preconditions.checkArgument(slot != null, "slot");
++        com.google.common.base.Preconditions.checkArgument(slot != EquipmentSlot.BODY, "Cannot get body item");
 +        return getHandle().getItemBySlot(org.bukkit.craftbukkit.CraftEquipmentSlot.getNMS(slot)).asBukkitMirror();
 +    }
 +
 +    @Override
 +    public void setItem(org.bukkit.inventory.EquipmentSlot slot, ItemStack item) {
-+        com.google.common.base.Preconditions.checkNotNull(slot, "slot");
++        com.google.common.base.Preconditions.checkArgument(slot != null, "slot");
++        com.google.common.base.Preconditions.checkArgument(slot != EquipmentSlot.BODY, "Cannot set body item");
 +        switch (slot) {
 +            case HAND:
 +                getEquipment().setItemInMainHand(item);

patches/server/Fix-equipment-slot-and-group-API.patch

@@ -5,6 +5,32 @@ Subject: [PATCH] Fix equipment slot and group API
 
 Add test for EquipmentSlotGroup
 
+diff --git a/src/main/java/org/bukkit/craftbukkit/inventory/CraftInventoryPlayer.java b/src/main/java/org/bukkit/craftbukkit/inventory/CraftInventoryPlayer.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/craftbukkit/inventory/CraftInventoryPlayer.java
++++ b/src/main/java/org/bukkit/craftbukkit/inventory/CraftInventoryPlayer.java
+@@ -0,0 +0,0 @@ public class CraftInventoryPlayer extends CraftInventory implements org.bukkit.i
+             case HEAD:
+                 this.setHelmet(item);
+                 break;
++                // Paper start
++            case BODY:
++                throw new IllegalArgumentException("BODY is not valid for players!");
++                // Paper end
+             default:
+                 throw new IllegalArgumentException("Not implemented. This is a bug");
+         }
+@@ -0,0 +0,0 @@ public class CraftInventoryPlayer extends CraftInventory implements org.bukkit.i
+                 return java.util.Objects.requireNonNullElseGet(this.getChestplate(), () -> new ItemStack(org.bukkit.Material.AIR)); // Paper - make nonnull
+             case HEAD:
+                 return java.util.Objects.requireNonNullElseGet(this.getHelmet(), () -> new ItemStack(org.bukkit.Material.AIR)); // Paper - make nonnull
++                // Paper start
++            case BODY:
++                throw new IllegalArgumentException("BODY is not valid for players!");
++                // Paper end
+             default:
+                 throw new IllegalArgumentException("Not implemented. This is a bug");
+         }
 diff --git a/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java b/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
 --- a/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java