prevent stack overflow caused by MoveInLineOfSight calls

should close #995 issue

--HG--
branch : trunk

3 files changed, 19 insertions, 3 deletions

diff --git a/src/game/CreatureAI.cpp b/src/game/CreatureAI.cpp
index e9f01098b03..9753008e3de 100644
--- a/src/game/CreatureAI.cpp
+++ b/src/game/CreatureAI.cpp
@@ -104,6 +104,17 @@ void CreatureAI::DoZoneInCombat(Creature* creature)
     }
 }
 
+// scripts does not take care about MoveInLineOfSight loops
+// MoveInLineOfSight can be called inside another MoveInLineOfSight and cause stack overflow
+void CreatureAI::MoveInLineOfSight_Safe(Unit *who)
+{   
+    if(m_MoveInLineOfSight_locked == true)
+        return;
+    m_MoveInLineOfSight_locked = true;
+    MoveInLineOfSight(who);
+    m_MoveInLineOfSight_locked = false;
+}
+
 void CreatureAI::MoveInLineOfSight(Unit *who)
 {
     if(me->getVictim())
diff --git a/src/game/CreatureAI.h b/src/game/CreatureAI.h
index 57480107e66..66aa2f2785f 100644
--- a/src/game/CreatureAI.h
+++ b/src/game/CreatureAI.h
@@ -83,14 +83,14 @@ class CreatureAI : public UnitAI
         Creature *DoSummonFlyer(uint32 uiEntry, WorldObject *obj, float fZ, float fRadius = 5.0f, uint32 uiDespawntime = 30000, TempSummonType uiType = TEMPSUMMON_CORPSE_TIMED_DESPAWN);
 
     public:
-        explicit CreatureAI(Creature *c) : UnitAI((Unit*)c), me(c), m_creature(c) {}
+        explicit CreatureAI(Creature *c) : UnitAI((Unit*)c), me(c), m_creature(c), m_MoveInLineOfSight_locked(false) {}
 
         virtual ~CreatureAI() {}
 
         ///== Reactions At =================================
 
         // Called if IsVisible(Unit *who) is true at each *who move, reaction at visibility zone enter
-        virtual void MoveInLineOfSight(Unit *);
+        void MoveInLineOfSight_Safe(Unit *who);
 
         // Called for reaction at stopping attack at no attackers or targets
         virtual void EnterEvadeMode();
@@ -174,7 +174,12 @@ class CreatureAI : public UnitAI
         virtual void PassengerBoarded(Unit *who, int8 seatId, bool apply) {}
 
     protected:
+        virtual void MoveInLineOfSight(Unit *);
+
         bool _EnterEvadeMode();
+
+    private:
+        bool m_MoveInLineOfSight_locked;
 };
 
 enum Permitions
diff --git a/src/game/GridNotifiers.cpp b/src/game/GridNotifiers.cpp
index 5617fe19358..0e7b60fa607 100644
--- a/src/game/GridNotifiers.cpp
+++ b/src/game/GridNotifiers.cpp
@@ -120,7 +120,7 @@ inline void CreatureUnitRelocationWorker(Creature* c, Unit* u)
 
     if(c->HasReactState(REACT_AGGRESSIVE) && !c->hasUnitState(UNIT_STAT_SIGHTLESS))
         if(c->_IsWithinDist(u, c->m_SightDistance, true) && c->IsAIEnabled)
-            c->AI()->MoveInLineOfSight(u);
+            c->AI()->MoveInLineOfSight_Safe(u);
 }
 
 void PlayerRelocationNotifier::Visit(PlayerMapType &m)