DoT's crash the server...

Well, a mob just killed my fiance's pet. Here is the result.
[code]
PeriodicTick: Creature (Entry: 2350 Guid: 16517) attacked Pet (Petnumber: 310 Guid: 1) for 10 dmg inflicted by 3396
DealDamageStart
deal dmg:10 to health:2
DealDamage Creature (Entry: 2350 Guid: 16517) Killed Pet (Petnumber: 310 Guid: 1)
DealDamageAttackStop
creature 1 stopped attacking creature 16122
creature 16122 stopped attacking creature 1
creature 16517 stopped attacking creature 1
SET JUST_DIED
Aura 3 now is remove mode 4
Aura 22 now is remove mode 4
Aura 79 now is remove mode 0
AURA MOD DAMAGE type:1 negative:0
Aura 133 now is remove mode 0
Aura 132 now is remove mode 0
DealDamageEnd returned 10 damage

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0xb20f3b70 (LWP 8257)]
0x064d1146 in ?? ()
(gdb) backtrace
#0 0x064d1146 in ?? ()
#1 0x088be8e0 in Aura::UpdateAura (this=0xb77cd3f0, diff=100)
at /home/---/zero/src/server/src/game/SpellAuras.h:455
#2 0x088bdc88 in SpellAuraHolder::Update (this=0xc4c8860, diff=100)
at /home/---/zero/src/server/src/game/SpellAuras.cpp:5445
#3 0x0878efcf in SpellAuraHolder::UpdateHolder (this=0xc4c8860, diff=100)
at /home/---/zero/src/server/src/game/SpellAuras.h:154
#4 0x0877ae41 in Unit::_UpdateSpells (this=0xc470308, time=100)
at /home/---/zero/src/server/src/game/Unit.cpp:2983
#5 0x08771cf2 in Unit::Update (this=0xc470308, update_diff=100, p_time=100)
at /home/---/zero/src/server/src/game/Unit.cpp:333
#6 0x08639ad6 in Creature::Update (this=0xc470308, update_diff=100, diff=100)
at /home/---/zero/src/server/src/game/Creature.cpp:582
#7 0x086e9f4a in Pet::Update (this=0xc470308, update_diff=100, diff=100)
at /home/---/zero/src/server/src/game/Pet.cpp:600
#8 0x0882982a in WorldObject::UpdateHelper::Update (this=0xb20f1fc4,
time_diff=100) at /home/---/zero/src/server/src/game/Object.h:473
#9 0x08849470 in MaNGOS::ObjectUpdater::Visit (this=0xb20f31a0, m=...)
at /home/---/zero/src/server/src/game/GridNotifiersImpl.h:54
#10 0x08856a60 in VisitorHelper<:objectupdater creature> (v=..., c=...)
at /home/---/zero/src/server/src/framework/GameSystem/TypeContainerVisitor.h:72
#11 0x088565c6 in VisitorHelper<:objectupdater creature typelist>, TypeList > > (v=..., c=...)
at /home/---/zero/src/server/src/framework/GameSystem/TypeContainerVisitor.h:85
#12 0x08855f7c in VisitorHelper<:objectupdater player typelist typenull> > > > (v=..., c=...)
at /home/---/zero/src/server/src/framework/GameSystem/TypeContainerVisitor.h:86
#13 0x088551d5 in VisitorHelper<:objectupdater typelist typenull> > > > > (v=..., c=...)
at /home/---/zero/src/server/src/framework/GameSystem/TypeContainerVisitor.h:98
#14 0x08853f34 in TypeContainerVisitor<:objectupdater typemapcontainer typelist typenull> > > > > >::Visit (this=0xb20f3198, c=...)
at /home/---/zero/src/server/src/framework/GameSystem/TypeContainerVisitor.h:127
#15 0x08852093 in Grid > > >, TypeList > > > >::Visit<:objectupdater> (this=0xc31c8fc, visitor=...)
at /home/---/zero/src/server/src/framework/GameSystem/Grid.h:111
#16 0x0884f77a in NGrid > > >, TypeListre, TypeList > > > >::Visit<:objectupdater typelist typenull> > > > > (this=0xc3135d0, x=@0xb20f20dc: 10, y=@0xb20f20d8: 8,
visitor=...)
at /home/---/zero/src/server/src/framework/GameSystem/NGrid.h:360
#17 0x0884b6c8 in Map::Visit<:objectupdater typemapcontainer typelist typenull> > > > > >
(this=0xb9acfa8, cell=..., visitor=...)
at /home/---/zero/src/server/src/game/Map.h:446
#18 0x088429f0 in Map::Update (this=0xb9acfa8, t_diff=@0xb20f323c: 100)
at /home/---/zero/src/server/src/game/Map.cpp:521
#19 0x08857f52 in MapManager::Update (this=0xb2fec70, diff=48)
at /home/---/zero/src/server/src/game/MapManager.cpp:184
#20 0x088e8401 in World::Update (this=0x8ce92b0, diff=48)
at /home/---/zero/src/server/src/game/World.cpp:1498
#21 0x0855402f in WorldRunnable::run (this=0xa4f2ad8)
at /home/---/zero/src/server/src/mangosd/WorldRunnable.cpp:66
#22 0x0897dca5 in ACE_Based::Thread::ThreadTask (param=0xa4f2ad8)
at /home/---/zero/src/server/src/shared/Threading.cpp:197
#23 0xb7f50171 in ACE_OS_Thread_Adapter::invoke() ()
from /usr/lib/libACE-6.0.3.so
#24 0xb7f121cf in ace_thread_adapter () from /usr/lib/libACE-6.0.3.so
#25 0xb77d6c39 in start_thread ()
from /lib/i386-linux-gnu/i686/cmov/libpthread.so.0
#26 0xb7743a6e in clone () from /lib/i386-linux-gnu/i686/cmov/libc.so.6
[/code]
We need to clamp damage so it cannot take more health than an NPC/mob/whatever has.

This is an outdated bug so all the debug lines are out of sync now. I can only guess what the might have been the error and here it is.

diff --git a/src/game/WorldHandlers/SpellAuras.cpp b/src/game/WorldHandlers/SpellAuras.cpp
index fb14a6f..08095b0 100644
--- a/src/game/WorldHandlers/SpellAuras.cpp
+++ b/src/game/WorldHandlers/SpellAuras.cpp
@@ -5533,6 +5533,10 @@ void SpellAuraHolder::Update(uint32 diff)
         }
     }
 
+	// DoTs-crash-the-server-r509 - Maybe Fix.
+	if (!m_target)
+		return;
+
     // Channeled aura required check distance from caster
     if (IsChanneledSpell(m_spellProto) && GetCasterGuid() != m_target->GetObjectGuid())
     {

edit: Damage is should not be the issue as it clamped here:

    if (Creature* victim = pVictim->ToCreature())
    {
        if (!victim->IsPet() && !victim->HasLootRecipient())
            victim->SetLootRecipient(this);

        if (IsControlledByPlayer()) // more narrow: IsPet(), IsGuardian() ?
            victim->LowerPlayerDamageReq(health < damage ? health : damage);
    }

Try this fix:

diff --git a/src/game/Object/Unit.cpp b/src/game/Object/Unit.cpp
index 08ba7cd..408960e 100644
--- a/src/game/Object/Unit.cpp
+++ b/src/game/Object/Unit.cpp
@@ -634,10 +634,11 @@ uint32 Unit::DealDamage(Unit* pVictim, uint32 damage, CleanDamage const* cleanDa
             victim->SetLootRecipient(this);
 
         if (IsControlledByPlayer()) // more narrow: IsPet(), IsGuardian() ?
-            victim->LowerPlayerDamageReq(health < damage ? health : damage);
+            victim->LowerPlayerDamageReq(victim->GetHealth() < damage ? victim->GetHealth() : damage);
+
     }
 
-    if (health <= damage)
+    if (pVictim->GetHealth() <= damage)
     {
         DEBUG_FILTER_LOG(LOG_FILTER_DAMAGE, "DealDamage %s Killed %s", GetGuidStr().c_str(), pVictim->GetGuidStr().c_str());