fix: preserve order of saved items to keep, close #186

paper/src/main/java/net/william278/husksync/listener/PaperEventListener.java

@@ -19,14 +19,17 @@
 
 package net.william278.husksync.listener;
 
+import com.google.common.collect.Lists;
 import net.william278.husksync.BukkitHuskSync;
 import net.william278.husksync.data.BukkitData;
 import net.william278.husksync.user.BukkitUser;
 import net.william278.husksync.user.OnlineUser;
 import org.bukkit.event.entity.PlayerDeathEvent;
 import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.PlayerInventory;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.Iterator;
 import java.util.List;
 
 import static net.william278.husksync.config.Settings.SynchronizationSettings.SaveOnDeathSettings;
@@ -57,7 +60,7 @@ public class PaperEventListener extends BukkitEventListener {
         final int maxInventorySize = BukkitData.Items.Inventory.INVENTORY_SLOT_COUNT;
         final List<ItemStack> itemsToSave = switch (settings.getItemsToSave()) {
             case DROPS -> event.getDrops();
-            case ITEMS_TO_KEEP -> event.getItemsToKeep();
+            case ITEMS_TO_KEEP -> preserveOrder(event.getEntity().getInventory(), event.getItemsToKeep());
         };
         if (itemsToSave.size() > maxInventorySize) {
             itemsToSave.subList(maxInventorySize, itemsToSave.size()).clear();
@@ -65,4 +68,22 @@ public class PaperEventListener extends BukkitEventListener {
         super.saveOnPlayerDeath(user, BukkitData.Items.ItemArray.adapt(itemsToSave));
     }
 
+    @NotNull
+    private List<ItemStack> preserveOrder(@NotNull PlayerInventory inventory, @NotNull List<ItemStack> toKeep) {
+        final List<ItemStack> preserved = Lists.newArrayList();
+        final List<ItemStack> items = Lists.newArrayList(inventory.getContents());
+        for (ItemStack item : toKeep) {
+            final Iterator<ItemStack> iterator = items.iterator();
+            while (iterator.hasNext()) {
+                final ItemStack originalItem = iterator.next();
+                if (originalItem != null && originalItem.equals(item)) {
+                    preserved.add(originalItem);
+                    iterator.remove();
+                    break;
+                }
+            }
+        }
+        return preserved;
+    }
+
 }