Core/GameObject: regenerate GO loot if respawn time passed since last loot generation time and not all items were taken

Port From (https://github.com/TrinityCore/TrinityCore/commit/98180ecdc179386270e93b80c0db8344b659557f)

Source/Game/Entities/GameObject/GameObject.cs

@@ -2655,6 +2655,8 @@ namespace Game.Entities
         void AddLootMode(LootModes lootMode) { m_LootMode |= lootMode; }
         void RemoveLootMode(LootModes lootMode) { m_LootMode &= ~lootMode; }
         void ResetLootMode() { m_LootMode = LootModes.Default; }
+        public void SetLootGenerationTime() { m_lootGenerationTime = (uint)Time.UnixTime; }
+        public uint GetLootGenerationTime() { return m_lootGenerationTime; }
 
         public void AddToSkillupList(ObjectGuid PlayerGuid) { m_SkillupList.Add(PlayerGuid); }
         public bool IsInSkillupList(ObjectGuid PlayerGuid)
@@ -2741,6 +2743,7 @@ namespace Game.Entities
         ObjectGuid m_lootRecipient;
         ObjectGuid m_lootRecipientGroup;
         LootModes m_LootMode;                                  // bitmask, default LOOT_MODE_DEFAULT, determines what loot will be lootable
+        uint m_lootGenerationTime;
         public uint m_groupLootTimer;                            // (msecs)timer used for group loot
         public ObjectGuid lootingGroupLowGUID;                         // used to find group which is looting
         long m_packedRotation;

Source/Game/Entities/Player/Player.Items.cs

@@ -6233,6 +6233,11 @@ namespace Game.Entities
 
                 loot = go.loot;
 
+                // loot was generated and respawntime has passed since then, allow to recreate loot
+                // to avoid bugs, this rule covers spawned gameobjects only
+                if (go.isSpawnedByDefault() && go.getLootState() == LootState.Activated && !go.loot.isLooted() && go.GetLootGenerationTime() + go.GetRespawnDelay() < Time.UnixTime)
+                    go.SetLootState(LootState.Ready);
+
                 if (go.getLootState() == LootState.Ready)
                 {
                     uint lootid = go.GetGoInfo().GetLootId();
@@ -6258,6 +6263,7 @@ namespace Game.Entities
                             group.UpdateLooterGuid(go, true);
 
                         loot.FillLoot(lootid, LootStorage.Gameobject, this, !groupRules, false, go.GetLootMode());
+                        go.SetLootGenerationTime();
 
                         // get next RR player (for next loot)
                         if (groupRules)