Core/Misc: don't allow players to use/activate/loot non-allowed gameobjects while under the effect of a damage immunity aura (#23319)

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

* Forgot to change this in last-second rename.

* Apply suggested changes, thanks Shauren!

# Conflicts:
#	src/server/game/Entities/GameObject/GameObject.cpp
#	src/server/game/Entities/Unit/UnitDefines.h
#	src/server/game/Entities/Unit/enuminfo_UnitDefines.cpp
#	src/server/scripts/Outland/CoilfangReservoir/TheSlavePens/boss_ahune.cpp

src/server/game/Entities/GameObject/GameObject.cpp

@@ -1428,6 +1428,12 @@ void GameObject::Use(Unit* user)
 
     if (Player* playerUser = user->ToPlayer())
     {
+        if (m_goInfo->CannotBeUsedUnderImmunity() && playerUser->HasFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_IMMUNE))
+            return;
+
+        if (!m_goInfo->IsUsableMounted())
+            playerUser->RemoveAurasByType(SPELL_AURA_MOUNTED);
+
         playerUser->PlayerTalkClass->ClearMenus();
         if (AI()->GossipHello(playerUser))
             return;

src/server/game/Entities/GameObject/GameObjectData.h

@@ -486,6 +486,21 @@ struct GameObjectTemplate
         }
     }
 
+    bool CannotBeUsedUnderImmunity() const // Cannot be used/activated/looted by players under immunity effects (example: Divine Shield)
+    {
+        switch (type)
+        {
+            case GAMEOBJECT_TYPE_DOOR:       return door.noDamageImmune != 0;
+            case GAMEOBJECT_TYPE_BUTTON:     return button.noDamageImmune != 0;
+            case GAMEOBJECT_TYPE_QUESTGIVER: return questgiver.noDamageImmune != 0;
+            case GAMEOBJECT_TYPE_CHEST:      return true;                           // All chests cannot be opened while immune on 3.3.5a
+            case GAMEOBJECT_TYPE_GOOBER:     return goober.noDamageImmune != 0;
+            case GAMEOBJECT_TYPE_FLAGSTAND:  return flagstand.noDamageImmune != 0;
+            case GAMEOBJECT_TYPE_FLAGDROP:   return flagdrop.noDamageImmune != 0;
+            default: return false;
+        }
+    }
+
     uint32 GetCharges() const                               // despawn at uses amount
     {
         switch (type)

src/server/game/Entities/Unit/UnitDefines.h

@@ -151,7 +151,7 @@ enum UnitFlags : uint32
     UNIT_FLAG_UNK_28                = 0x10000000,
     UNIT_FLAG_UNK_29                = 0x20000000,           // used in Feing Death spell
     UNIT_FLAG_SHEATHE               = 0x40000000,
-    UNIT_FLAG_UNK_31                = 0x80000000,
+    UNIT_FLAG_IMMUNE                = 0x80000000,           // Immune to damage
     MAX_UNIT_FLAGS = 33
 };
 

src/server/game/Spells/Auras/SpellAuraEffects.cpp

@@ -3269,7 +3269,17 @@ void AuraEffect::HandleAuraModSchoolImmunity(AuraApplication const* aurApp, uint
         target->RemoveAurasWithInterruptFlags(AURA_INTERRUPT_FLAG_IMMUNE_OR_LOST_SELECTION);
 
     if (apply)
+    {
+        target->SetFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_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->RemoveFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_IMMUNE);
+    }
 }
 
 void AuraEffect::HandleAuraModDmgImmunity(AuraApplication const* aurApp, uint8 mode, bool apply) const

src/server/game/Spells/Spell.cpp

@@ -5402,6 +5402,13 @@ SpellCastResult Spell::CheckCast(bool strict, uint32* param1 /*= nullptr*/, uint
     if (!m_caster->IsAlive() && !m_spellInfo->IsPassive() && !(m_spellInfo->HasAttribute(SPELL_ATTR0_CASTABLE_WHILE_DEAD) || (IsTriggered() && !m_triggeredByAuraSpell)))
         return SPELL_FAILED_CASTER_DEAD;
 
+    // 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->ToPlayer() && m_targets.GetGOTarget())
+    {
+        if (m_targets.GetGOTarget()->GetGOInfo()->CannotBeUsedUnderImmunity() && m_caster->HasFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_IMMUNE))
+            return SPELL_FAILED_DONT_REPORT;
+    }
+
     // check cooldowns to prevent cheating
     if (!m_spellInfo->IsPassive())
     {

src/server/game/Spells/SpellEffects.cpp

@@ -1600,6 +1600,10 @@ void Spell::EffectOpenLock(SpellEffIndex effIndex)
     if (gameObjTarget)
     {
         GameObjectTemplate const* goInfo = gameObjTarget->GetGOInfo();
+
+        if (goInfo->CannotBeUsedUnderImmunity() && m_caster->HasFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_IMMUNE))
+            return;
+
         // Arathi Basin banner opening. /// @todo Verify correctness of this check
         if ((goInfo->type == GAMEOBJECT_TYPE_BUTTON && goInfo->button.noDamageImmune) ||
             (goInfo->type == GAMEOBJECT_TYPE_GOOBER && goInfo->goober.losOK))

src/server/scripts/Northrend/VioletHold/boss_ichoron.cpp

@@ -312,13 +312,13 @@ class spell_ichoron_drained : public SpellScriptLoader
 
             void HandleApply(AuraEffect const* /*aurEff*/, AuraEffectHandleModes /*mode*/)
             {
-                GetTarget()->SetFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_NOT_SELECTABLE | UNIT_FLAG_UNK_31);
+                GetTarget()->SetFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_NOT_SELECTABLE);
                 GetTarget()->SetFlag(UNIT_FIELD_FLAGS_2, UNIT_FLAG2_FEIGN_DEATH);
             }
 
             void HandleRemove(AuraEffect const* /*aurEff*/, AuraEffectHandleModes /*mode*/)
             {
-                GetTarget()->RemoveFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_NOT_SELECTABLE | UNIT_FLAG_UNK_31);
+                GetTarget()->RemoveFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_NOT_SELECTABLE);
                 GetTarget()->RemoveFlag(UNIT_FIELD_FLAGS_2, UNIT_FLAG2_FEIGN_DEATH);
 
                 if (GetTargetApplication()->GetRemoveMode().HasFlag(AuraRemoveFlags::Expired))

src/server/scripts/Outland/CoilfangReservoir/TheSlavePens/boss_ahune.cpp

@@ -277,7 +277,6 @@ public:
             if (Creature* frozenCore = ObjectAccessor::GetCreature(*me, instance->GetGuidData(DATA_FROZEN_CORE)))
                 frozenCore->AI()->DoAction(ACTION_AHUNE_RETREAT);
             me->RemoveAurasDueToSpell(SPELL_AHUNES_SHIELD);
-            me->SetFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_UNK_31);
             DoCast(me, SPELL_SUBMERGED, true);
             DoCast(me, SPELL_AHUNE_SELF_STUN, true);
             DoCast(me, SPELL_STAY_SUBMERGED, true);