Core/Misc: don't allow players to use/activate/loot non-allowed gameobjects while under the effect of a damage immunity aura

Port From (https://github.com/TrinityCore/TrinityCore/commit/9d865f7536ae6feda6fba77785e4548f95ca5d03)

Source/Framework/Constants/CreatureConst.cs

@@ -79,7 +79,7 @@ namespace Framework.Constants
         Unk28 = 0x10000000,
         Unk29 = 0x20000000,
         Sheathe = 0x40000000,
-        Unk31 = 0x80000000
+        Immune = 0x80000000
     }
 
     public enum UnitFlags2 : uint

Source/Game/Entities/GameObject/GameObject.cs

@@ -1448,6 +1448,9 @@ namespace Game.Entities
             Player playerUser = user.ToPlayer();
             if (playerUser != null)
             {
+                if (m_goInfo.GetNoDamageImmune() != 0 && playerUser.HasUnitFlag(UnitFlags.Immune))
+                    return;
+
                 if (!m_goInfo.IsUsableMounted())
                     playerUser.RemoveAurasByType(AuraType.Mounted);
 

Source/Game/Entities/GameObject/GameObjectData.cs

@@ -352,7 +352,37 @@ namespace Game.Entities
             }
         }
 
-        // despawn at uses amount
+        /// <summary>
+        /// Cannot be used/activated/looted by players under immunity effects (example: Divine Shield)
+        /// </summary>
+        /// <returns></returns>
+        public uint GetNoDamageImmune()
+        {
+            switch (type)
+            {
+                case GameObjectTypes.Door:
+                    return Door.noDamageImmune;
+                case GameObjectTypes.Button:
+                    return Button.noDamageImmune;
+                case GameObjectTypes.QuestGiver:
+                    return QuestGiver.noDamageImmune;
+                case GameObjectTypes.Chest:
+                    return 1;
+                case GameObjectTypes.Goober:
+                    return Goober.noDamageImmune;
+                case GameObjectTypes.FlagStand:
+                    return FlagStand.noDamageImmune;
+                case GameObjectTypes.FlagDrop:
+                    return FlagDrop.noDamageImmune;
+                default:
+                    return 0;
+            }
+        }
+        
+        /// <summary>
+        /// despawn at uses amount
+        /// </summary>
+        /// <returns></returns>
         public uint GetCharges()
         {
             switch (type)

Source/Game/Spells/Auras/AuraEffect.cs

@@ -2799,7 +2799,18 @@ namespace Game.Spells
             }
 
             if (apply)
+            {
+                target.AddUnitFlag(UnitFlags.Immune);
                 target.GetThreatManager().EvaluateSuppressed();
+            }
+            else
+            {
+                // do not remove unit flag if there are more than this auraEffect of that kind on unit
+                if (target.HasAuraType(GetAuraType()))
+                    return;
+
+                target.RemoveUnitFlag(UnitFlags.Immune);
+            }
         }
 
         [AuraEffectHandler(AuraType.DamageImmunity)]

Source/Game/Spells/Spell.cs

@@ -4365,6 +4365,13 @@ namespace Game.Spells
             if (m_caster.ToUnit() && !m_caster.ToUnit().IsAlive() && !m_spellInfo.IsPassive() && !(m_spellInfo.HasAttribute(SpellAttr0.CastableWhileDead) || (IsTriggered() && m_triggeredByAuraSpell == null)))
                 return SpellCastResult.CasterDead;
 
+            // Prevent cheating in case the player has an immunity effect and tries to interact with a non-allowed gameobject. The error message is handled by the client so we don't report anything here
+            if (m_caster.IsPlayer() && m_targets.GetGOTarget() != null)
+            {
+                if (m_targets.GetGOTarget().GetGoInfo().GetNoDamageImmune() != 0 && m_caster.ToUnit().HasUnitFlag(UnitFlags.Immune))
+                    return SpellCastResult.DontReport;
+            }
+
             // check cooldowns to prevent cheating
             if (!m_spellInfo.IsPassive())
             {

Source/Game/Spells/SpellEffects.cs

@@ -1324,6 +1324,10 @@ namespace Game.Spells
             if (gameObjTarget != null)
             {
                 GameObjectTemplate goInfo = gameObjTarget.GetGoInfo();
+
+                if (goInfo.GetNoDamageImmune() != 0 && player.HasUnitFlag(UnitFlags.Immune))
+                    return;
+
                 // Arathi Basin banner opening. // @todo Verify correctness of this check
                 if ((goInfo.type == GameObjectTypes.Button && goInfo.Button.noDamageImmune != 0) ||
                     (goInfo.type == GameObjectTypes.Goober && goInfo.Goober.requireLOS != 0))