*Backport a crash fix from TC2. Fix a crash caused by stealing single target aura. Source: Mangos.

--HG--
branch : trunk

src/game/SpellAuras.cpp

@@ -352,6 +352,8 @@ m_periodicTimer(0), m_PeriodicEventId(0), m_AuraDRGroup(DIMINISHING_NONE)
 
     m_applyTime = time(NULL);
 
+    m_isSingleTargetAura = IsSingleTargetSpell(m_spellProto);
+
     if(!caster)
     {
         m_caster_guid = target->GetGUID();
@@ -6176,3 +6178,21 @@ void Aura::HandleArenaPreparation(bool apply, bool Real)
         m_target->RemoveFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_PREPARATION);
 }
 
+void Aura::UnregisterSingleCastAura()
+{
+    if (IsSingleTarget())
+    {
+        Unit* caster = NULL;
+        caster = GetCaster();
+        if(caster)
+        {
+            caster->GetSingleCastAuras().remove(this);
+        }
+        else
+        {
+            sLog.outError("Couldn't find the caster of the single target aura, may crash later!");
+            assert(false);
+        }
+        m_isSingleTargetAura = false;
+    }
+}

src/game/SpellAuras.h

@@ -310,6 +310,11 @@ class TRINITY_DLL_SPEC Aura
 
         int32 GetStackAmount() {return m_stackAmount;}
         void SetStackAmount(int32 amount) {m_stackAmount=amount;}
+
+        // Single cast aura helpers
+        void UnregisterSingleCastAura();
+        bool IsSingleTarget() const {return m_isSingleTargetAura;}
+        void SetIsSingleTarget(bool val) { m_isSingleTargetAura = val;}
     protected:
         Aura(SpellEntry const* spellproto, uint32 eff, int32 *currentBasePoints, Unit *target, Unit *caster = NULL, Item* castItem = NULL);
 
@@ -342,6 +347,7 @@ class TRINITY_DLL_SPEC Aura
         bool m_isRemovedOnShapeLost:1;
         bool m_updated:1;
         bool m_in_use:1;                                    // true while in Aura::ApplyModifier call
+        bool m_isSingleTargetAura:1;                        // true if it's a single target spell and registered at caster - can change at spell steal for example
 
         int32 m_periodicTimer;
         uint32 m_PeriodicEventId;

src/game/Unit.cpp

@@ -3822,7 +3822,7 @@ bool Unit::AddAura(Aura *Aur)
     }
 
     // update single target auras list (before aura add to aura list, to prevent unexpected remove recently added aura)
-    if (IsSingleTargetSpell(aurSpellInfo) && Aur->GetTarget())
+    if (Aur->IsSingleTarget() && Aur->GetTarget())
     {
         // caster pointer can be deleted in time aura remove, find it by guid at each iteration
         for(;;)
@@ -4160,9 +4160,12 @@ void Unit::RemoveAurasDueToSpellBySteal(uint32 spellId, uint64 casterGUID, Unit
             new_aur->SetAuraMaxDuration( max_dur > dur ? dur : max_dur );
             new_aur->SetAuraDuration( max_dur > dur ? dur : max_dur );
 
+            // Unregister _before_ adding to stealer
+            aur->UnregisterSingleCastAura();
+            // strange but intended behaviour: Stolen single target auras won't be treated as single targeted
+            new_aur->SetIsSingleTarget(false);
             // add the new aura to stealer
             stealer->AddAura(new_aur);
-
             // Remove aura as dispel
             RemoveAura(iter, AURA_REMOVE_BY_DISPEL);
         }
@@ -4309,20 +4312,7 @@ void Unit::RemoveAura(AuraMap::iterator &i, AuraRemoveMode mode)
     ++m_removedAuras;                                       // internal count used by unit update
 
     Unit* caster = NULL;
-    if (IsSingleTargetSpell(AurSpellInfo))
-    {
-        caster = Aur->GetCaster();
-        if(caster)
-        {
-            AuraList& scAuras = caster->GetSingleCastAuras();
-            scAuras.remove(Aur);
-        }
-        else
-        {
-            sLog.outError("Couldn't find the caster of the single target aura, may crash later!");
-            assert(false);
-        }
-    }
+    Aur->UnregisterSingleCastAura();
 
     // remove from list before mods removing (prevent cyclic calls, mods added before including to aura list - use reverse order)
     if (Aur->GetModifier()->m_auraname < TOTAL_AURAS)
@@ -13087,4 +13077,3 @@ void Unit::AddAura(uint32 spellId, Unit* target)
         }
     }
 }
-