Violet Hold: Fix portal #2 spawning. Some minor cleansing and pointer checks

--HG--
branch : trunk

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

@@ -444,7 +444,7 @@ struct npc_teleportation_portalAI : public ScriptedAI
         listOfMobs.Summon(pSummoned);
     }
 
-    void SummonedCreatureDespawn(Creature *pSummoned)
+    void SummonedMobDied(Creature *pSummoned)
     {
         listOfMobs.Despawn(pSummoned);
     }
@@ -461,6 +461,7 @@ struct violet_hold_trashAI : public npc_escortAI
     {
         pInstance = c->GetInstanceData();
         bHasGotMovingPoints = false;
+        if (pInstance)
             portalLocationID = pInstance->GetData(DATA_PORTAL_LOCATION);
         Reset();
     }
@@ -561,7 +562,9 @@ struct violet_hold_trashAI : public npc_escortAI
 
     void JustDied(Unit *unit)
     {
-        Creature* portal = Unit::GetCreature((*me),pInstance->GetData64(DATA_TELEPORTATION_PORTAL));
+        if (Creature* portal = Unit::GetCreature((*me),pInstance->GetData64(DATA_TELEPORTATION_PORTAL)))
+            CAST_AI(npc_teleportation_portalAI,portal->AI())->SummonedMobDied(me);
+        if (pInstance)
             pInstance->SetData(DATA_NPC_PRESENCE_AT_DOOR_REMOVE,1);
     }
 
@@ -569,6 +572,7 @@ struct violet_hold_trashAI : public npc_escortAI
     {
         me->SetReactState(REACT_PASSIVE);
         DoCast(SPELL_DESTROY_DOOR_SEAL);
+        if (pInstance)
             pInstance->SetData(DATA_NPC_PRESENCE_AT_DOOR_ADD,1);
     }