bugfix: prevent quest item pickup by players without active quest

src/DataModel/Configuration/Items/ItemDefinition.cs

@@ -50,6 +50,14 @@ public partial class ItemDefinition
     /// </summary>
     public bool IsBoundToCharacter { get; set; }
 
+    /// <summary>
+    /// Gets or sets a value indicating whether items of this kind are quest items.
+    /// Quest items may additionally only be picked up from the ground by a character
+    /// which has an active quest that requires them, even if the character is a member
+    /// of the party which killed the monster that dropped it.
+    /// </summary>
+    public bool IsQuestItem { get; set; }
+
     /// <summary>
     /// Gets or sets the storage limit per character which is checked on pick-up.
     /// A value of 0 means, that there is no limit.

src/GameLogic/DroppedItem.cs

@@ -174,7 +174,17 @@ private async void DisposeAndDelete(object? state)
         }
     }
 
-    private bool IsPlayerAnOwner(Player player)
+    /// <summary>
+    /// Gets a value indicating whether the owner-pickup priority period is still active.
+    /// </summary>
+    public bool IsOwnerPickupPriorityActive => DateTime.UtcNow < this._dropTimestamp.Add(TimeUntilDropIsFree);
+
+    /// <summary>
+    /// Determines whether the specified player is an owner of this dropped item.
+    /// </summary>
+    /// <param name="player">The player.</param>
+    /// <returns><c>true</c> if the player is an owner; otherwise, <c>false</c>.</returns>
+    public bool IsPlayerAnOwner(Player player)
     {
         return this._owners?.Contains(player) ?? true;
     }

src/GameLogic/PlayerActions/Items/PickupItemAction.cs

@@ -5,6 +5,7 @@
 namespace MUnique.OpenMU.GameLogic.PlayerActions.Items;
 
 using MUnique.OpenMU.DataModel.Configuration.Items;
+using MUnique.OpenMU.DataModel.Configuration.Quests;
 using MUnique.OpenMU.GameLogic.Views;
 using MUnique.OpenMU.GameLogic.Views.Inventory;
 using MUnique.OpenMU.Interfaces;
@@ -61,6 +62,12 @@ public async ValueTask PickupItemAsync(Player player, ushort dropId)
         }
     }
 
+    private static async ValueTask<(bool Success, Item? StackTarget)> RejectAsync(Player player, string messageKey)
+    {
+        await player.ShowLocalizedBlueMessageAsync(messageKey).ConfigureAwait(false);
+        return (false, null);
+    }
+
     private static bool CanPickup(Player player, ILocateable droppedLocateable)
     {
         if (!player.IsAlive)
@@ -92,6 +99,21 @@ private static bool IsLimitReached(Player player, ItemDefinition? itemDefinition
         return player.Inventory?.Items.Count(item => item.Definition == itemDefinition) >= itemDefinition.StorageLimitPerCharacter;
     }
 
+    private static bool PlayerHasActiveQuestForItem(Player player, Item item)
+    {
+        var questStates = player.SelectedCharacter?.QuestStates;
+        if (questStates is null)
+        {
+            return false;
+        }
+
+        return questStates
+            .Select(q => q.ActiveQuest)
+            .OfType<QuestDefinition>()
+            .SelectMany(q => q.RequiredItems)
+            .Any(r => r.Item == item.Definition && (r.DropItemGroup?.ItemLevel is null || r.DropItemGroup.ItemLevel == item.Level));
+    }
+
     private static async ValueTask<(bool Success, Item? StackTarget)> TryPickupItemAsync(Player player, DroppedItem droppedItem)
     {
         if (!CanPickup(player, droppedItem))
@@ -119,6 +141,23 @@ private static bool IsLimitReached(Player player, ItemDefinition? itemDefinition
             return (false, null);
         }
 
+        if (droppedItem.Item.Definition?.IsQuestItem == true
+            && !PlayerHasActiveQuestForItem(player, droppedItem.Item))
+        {
+            return await RejectAsync(player, nameof(PlayerMessage.ItemDoesNotBelongToYou)).ConfigureAwait(false);
+        }
+
+        if (droppedItem.Item.Definition?.IsBoundToCharacter == true
+            && !droppedItem.IsPlayerAnOwner(player))
+        {
+            return await RejectAsync(player, nameof(PlayerMessage.ItemDoesNotBelongToYou)).ConfigureAwait(false);
+        }
+
+        if (!droppedItem.IsPlayerAnOwner(player) && droppedItem.IsOwnerPickupPriorityActive)
+        {
+            return await RejectAsync(player, nameof(PlayerMessage.ItemDoesNotBelongToYou)).ConfigureAwait(false);
+        }
+
         var result = await droppedItem.TryPickUpByAsync(player).ConfigureAwait(false);
         if (result.Success)
         {

src/GameLogic/Properties/PlayerMessage.resx

@@ -699,4 +699,7 @@
   <data name="PkClearYouAreNotPlayerKiller" xml:space="preserve">
     <value>You are not a Player Killer.</value>
   </data>
+  <data name="ItemDoesNotBelongToYou" xml:space="preserve">
+    <value>This item doesn't belong to you.</value>
+  </data>
 </root>