Core/Loot: fix some issues with master loot and don't allow players to see soulbound recipes that they already learned in the loot window.

Port From (https://github.com/TrinityCore/TrinityCore/commit/7b346bcf8d4c4b39685a46ef09f389c8a317b566)

Source/Framework/Constants/ItemConst.cs

@@ -1016,6 +1016,7 @@ namespace Framework.Constants
         NoSpellEffectTooltipPrefixes = 0x20000
     }
 
+    [Flags]
     public enum ItemFlagsCustom
     {
         Unused = 0x0001,

Source/Game/Handlers/LootHandler.cs

@@ -521,7 +521,7 @@ namespace Game
 
                 List<ItemPosCount> dest = new();
                 InventoryResult msg = target.CanStoreNewItem(ItemConst.NullBag, ItemConst.NullSlot, dest, item.itemid, item.count);
-                if (item.follow_loot_rules && !item.AllowedForPlayer(target))
+                if (!item.AllowedForPlayer(target, true))
                     msg = InventoryResult.CantEquipEver;
                 if (msg != InventoryResult.Ok)
                 {
@@ -532,7 +532,6 @@ namespace Game
                     else
                         _player.SendLootError(req.Object, ObjectGuid.Empty, LootError.MasterOther);
 
-                    target.SendEquipError(msg, null, null, item.itemid);
                     return;
                 }
 

Source/Game/Loot/Loot.cs

@@ -43,7 +43,7 @@ namespace Game.Loots
             randomBonusListId = ItemEnchantmentManager.GenerateItemRandomBonusListId(itemid);
         }
 
-        public bool AllowedForPlayer(Player player)
+        public bool AllowedForPlayer(Player player, bool isGivenByMasterLooter = false)
         {
             // DB conditions check
             if (!Global.ConditionMgr.IsObjectMeetToConditions(player, conditions))
@@ -53,10 +53,6 @@ namespace Game.Loots
             if (pProto == null)
                 return false;
 
-            // not show loot for players without profession or those who already know the recipe
-            if (pProto.GetFlags().HasAnyFlag(ItemFlags.HideUnusableRecipe) && (!player.HasSkill((SkillType)pProto.GetRequiredSkill()) || player.HasSpell((uint)pProto.Effects[1].SpellID)))
-                return false;
-
             // not show loot for not own team
             if (pProto.GetFlags2().HasAnyFlag(ItemFlags2.FactionHorde) && player.GetTeam() != Team.Horde)
                 return false;
@@ -64,6 +60,45 @@ namespace Game.Loots
             if (pProto.GetFlags2().HasAnyFlag(ItemFlags2.FactionAlliance) && player.GetTeam() != Team.Alliance)
                 return false;
 
+            // Master looter can see certain items even if the character can't loot them
+            if (!isGivenByMasterLooter && player.GetGroup() && player.GetGroup().GetMasterLooterGuid() == player.GetGUID())
+            {
+                // check quest requirements
+                if (!pProto.FlagsCu.HasFlag(ItemFlagsCustom.IgnoreQuestStatus) && (needs_quest || pProto.GetStartQuest() != 0))
+                    return false;
+
+                return true;
+            }
+
+            // Don't allow loot for players without profession or those who already know the recipe
+            if (pProto.GetFlags().HasFlag(ItemFlags.HideUnusableRecipe))
+            {
+                if (!player.HasSkill((SkillType)pProto.GetRequiredSkill()))
+                    return false;
+
+                foreach (var itemEffect in pProto.Effects)
+                {
+                    if (itemEffect.TriggerType != ItemSpelltriggerType.LearnSpellId)
+                        continue;
+
+                    if (player.HasSpell((uint)itemEffect.SpellID))
+                        return false;
+                }
+            }
+
+            // Don't allow to loot soulbound recipes that the player has already learned
+            if (pProto.GetClass() == ItemClass.Recipe && pProto.GetBonding() == ItemBondingType.OnAcquire)
+            {
+                foreach (var itemEffect in pProto.Effects)
+                {
+                    if (itemEffect.TriggerType != ItemSpelltriggerType.LearnSpellId)
+                        continue;
+
+                    if (player.HasSpell((uint)itemEffect.SpellID))
+                        return false;
+                }
+            }
+
             // check quest requirements
             if (!pProto.FlagsCu.HasAnyFlag(ItemFlagsCustom.IgnoreQuestStatus)
                 && ((needs_quest || (pProto.GetStartQuest() != 0 && player.GetQuestStatus(pProto.GetStartQuest()) != QuestStatus.None)) && !player.HasQuestForItem(itemid)))