Core/Auras: Recheck aura presence on target after calling linked events in charm and vehicle aura effect handlers.

src/server/game/Entities/Unit/Unit.cpp

@@ -15275,7 +15275,7 @@ void Unit::SetConfused(bool apply)
         this->ToPlayer()->SetClientControl(this, !apply);
 }
 
-bool Unit::SetCharmedBy(Unit* charmer, CharmType type)
+bool Unit::SetCharmedBy(Unit* charmer, CharmType type, AuraApplication const * aurApp)
 {
     if (!charmer)
         return false;
@@ -15336,6 +15336,11 @@ bool Unit::SetCharmedBy(Unit* charmer, CharmType type)
         return false;
     }
 
+    // charm is set by aura, and aura effect remove handler was called during apply handler execution
+    // prevent undefined behaviour
+    if (aurApp && aurApp->GetRemoveMode())
+        return false;
+
     // Set charmed
     Map* pMap = GetMap();
     if (!IsVehicle() || (IsVehicle() && pMap && !pMap->IsBattleground()))
@@ -15355,6 +15360,11 @@ bool Unit::SetCharmedBy(Unit* charmer, CharmType type)
         this->ToPlayer()->SetClientControl(this, 0);
     }
 
+    // charm is set by aura, and aura effect remove handler was called during apply handler execution
+    // prevent undefined behaviour
+    if (aurApp && aurApp->GetRemoveMode())
+        return false;
+
     // Pets already have a properly initialized CharmInfo, don't overwrite it.
     if (type != CHARM_TYPE_VEHICLE && !GetCharmInfo())
     {
@@ -16308,7 +16318,7 @@ bool Unit::CheckPlayerCondition(Player* pPlayer)
     }
 }
 
-void Unit::EnterVehicle(Vehicle *vehicle, int8 seatId, bool byAura)
+void Unit::EnterVehicle(Vehicle *vehicle, int8 seatId, AuraApplication const * aurApp)
 {
     if (!isAlive() || GetVehicleKit() == vehicle)
         return;
@@ -16320,7 +16330,7 @@ void Unit::EnterVehicle(Vehicle *vehicle, int8 seatId, bool byAura)
             if (seatId >= 0 && seatId != GetTransSeat())
             {
                 sLog->outDebug("EnterVehicle: %u leave vehicle %u seat %d and enter %d.", GetEntry(), m_vehicle->GetBase()->GetEntry(), GetTransSeat(), seatId);
-                ChangeSeat(seatId, byAura);
+                ChangeSeat(seatId, bool(aurApp));
             }
             return;
         }
@@ -16347,9 +16357,14 @@ void Unit::EnterVehicle(Vehicle *vehicle, int8 seatId, bool byAura)
             bg->EventPlayerDroppedFlag(plr);
     }
 
+    // vehicle is applied by aura, and aura effect remove handler was called during apply handler execution
+    // prevent undefined behaviour
+    if (aurApp && aurApp->GetRemoveMode())
+        return;
+
     ASSERT(!m_vehicle);
     m_vehicle = vehicle;
-    if (!m_vehicle->AddPassenger(this, seatId, byAura))
+    if (!m_vehicle->AddPassenger(this, seatId, bool(aurApp)))
     {
         m_vehicle = NULL;
         return;

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

@@ -1564,7 +1564,7 @@ class Unit : public WorldObject
         void RemoveAllMinionsByEntry(uint32 entry);
         void SetCharm(Unit* target, bool apply);
         Unit* GetNextRandomRaidMemberOrPet(float radius);
-        bool SetCharmedBy(Unit* charmer, CharmType type);
+        bool SetCharmedBy(Unit* charmer, CharmType type, AuraApplication const * aurApp = NULL);
         void RemoveCharmedBy(Unit* charmer);
         void RestoreFaction();
 
@@ -2028,8 +2028,8 @@ class Unit : public WorldObject
         bool m_ControlledByPlayer;
 
         bool CheckPlayerCondition(Player* pPlayer);
-        void EnterVehicle(Unit *base, int8 seatId = -1, bool byAura = false) { EnterVehicle(base->GetVehicleKit(), seatId, byAura); }
-        void EnterVehicle(Vehicle *vehicle, int8 seatId = -1, bool byAura = false);
+        void EnterVehicle(Unit *base, int8 seatId = -1, AuraApplication const * aurApp = NULL) { EnterVehicle(base->GetVehicleKit(), seatId, aurApp); }
+        void EnterVehicle(Vehicle *vehicle, int8 seatId = -1, AuraApplication const * aurApp = NULL);
         void ExitVehicle();
         void ChangeSeat(int8 seatId, bool next = true, bool byAura = false);