Pct damage reduction effects fix

gistfile1.diff

diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index cced511..39ded27 100755
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -10756,20 +10756,11 @@ uint32 Unit::SpellDamageBonus(Unit* victim, SpellEntry const* spellProto, uint32
     }
 
     // ..taken
-    int32 maxPositiveMod = 0; // max of the positive amount aura (that increase the damage taken)
-    int32 sumNegativeMod = 0; // sum the negative amount aura (that reduce the damage taken)
-    AuraEffectList const& mModDamagePercentTaken = victim->GetAuraEffectsByType(SPELL_AURA_MOD_DAMAGE_PERCENT_TAKEN);
-    for (AuraEffectList::const_iterator i = mModDamagePercentTaken.begin(); i != mModDamagePercentTaken.end(); ++i)
-        if ((*i)->GetMiscValue() & GetSpellSchoolMask(spellProto))
-        {
-            if ((*i)->GetAmount() > 0)
-            {
-                if ((*i)->GetAmount() > maxPositiveMod)
-                    maxPositiveMod = (*i)->GetAmount();
-            }
-            else
-                sumNegativeMod += (*i)->GetAmount();
-        }
+    float TakenTotalMod = 1.0f;
+
+    // from positive and negative SPELL_AURA_MOD_DAMAGE_PERCENT_TAKEN
+    // multiplicative bonus, for example Dispersion + Shadowform (0.10*0.85=0.085)
+    TakenTotalMod *= victim->GetTotalAuraMultiplierByMiscMask(SPELL_AURA_MOD_DAMAGE_PERCENT_TAKEN, GetSpellSchoolMask(spellProto));
 
     // .. taken pct: dummy auras
     AuraEffectList const& mDummyAuras = victim->GetAuraEffectsByType(SPELL_AURA_DUMMY);
@@ -10786,16 +10777,13 @@ uint32 Unit::SpellDamageBonus(Unit* victim, SpellEntry const* spellProto, uint32
                     float mod = victim->ToPlayer()->GetRatingBonusValue(CR_CRIT_TAKEN_MELEE) * (-8.0f);
                     if (mod < (*i)->GetAmount())
                         mod = (float)(*i)->GetAmount();
-                    sumNegativeMod += int32(mod);
+                    AddPctF(TakenTotalMod, mod);
                 }
                 break;
             // Ebon Plague
             case 1933:
                 if ((*i)->GetMiscValue() & (spellProto ? GetSpellSchoolMask(spellProto) : 0))
-                {
-                    if ((*i)->GetAmount() > maxPositiveMod)
-                        maxPositiveMod = (*i)->GetAmount();
-                }
+                    AddPctF(TakenTotalMod, (*i)->GetAmount());
                 break;
         }
     }
@@ -10804,7 +10792,7 @@ uint32 Unit::SpellDamageBonus(Unit* victim, SpellEntry const* spellProto, uint32
     AuraEffectList const& mOwnerTaken = victim->GetAuraEffectsByType(SPELL_AURA_MOD_DAMAGE_FROM_CASTER);
     for (AuraEffectList::const_iterator i = mOwnerTaken.begin(); i != mOwnerTaken.end(); ++i)
         if ((*i)->GetCasterGUID() == GetGUID() && (*i)->IsAffectedOnSpell(spellProto))
-            sumNegativeMod += (*i)->GetAmount();
+            AddPctF(TakenTotalMod, (*i)->GetAmount());
 
     // Mod damage from spell mechanic
     if (uint32 mechanicMask = GetAllSpellMechanicMask(spellProto))
@@ -10812,11 +10800,9 @@ uint32 Unit::SpellDamageBonus(Unit* victim, SpellEntry const* spellProto, uint32
         AuraEffectList const& mDamageDoneMechanic = victim->GetAuraEffectsByType(SPELL_AURA_MOD_MECHANIC_DAMAGE_TAKEN_PERCENT);
         for (AuraEffectList::const_iterator i = mDamageDoneMechanic.begin(); i != mDamageDoneMechanic.end(); ++i)
             if (mechanicMask & uint32(1<<((*i)->GetMiscValue())))
-                sumNegativeMod += (*i)->GetAmount();
+                AddPctF(TakenTotalMod, (*i)->GetAmount());
     }
 
-    float TakenTotalMod = (sumNegativeMod + maxPositiveMod + 100.0f) / 100.0f;
-
     // Taken/Done fixed damage bonus auras
     int32 DoneAdvertisedBenefit  = SpellBaseDamageBonus(GetSpellSchoolMask(spellProto));
     int32 TakenAdvertisedBenefit = SpellBaseDamageBonusForVictim(GetSpellSchoolMask(spellProto), victim);
@@ -11937,10 +11923,7 @@ void Unit::MeleeDamageBonus(Unit* victim, uint32 *pdamage, WeaponAttackType attT
         }
 
     // ..taken
-    AuraEffectList const& mModDamagePercentTaken = victim->GetAuraEffectsByType(SPELL_AURA_MOD_DAMAGE_PERCENT_TAKEN);
-    for (AuraEffectList::const_iterator i = mModDamagePercentTaken.begin(); i != mModDamagePercentTaken.end(); ++i)
-        if ((*i)->GetMiscValue() & GetMeleeDamageSchoolMask())
-            AddPctN(TakenTotalMod, (*i)->GetAmount());
+    TakenTotalMod *= victim->GetTotalAuraMultiplierByMiscMask(SPELL_AURA_MOD_DAMAGE_PERCENT_TAKEN, GetMeleeDamageSchoolMask());
 
     // From caster spells
     AuraEffectList const& mOwnerTaken = victim->GetAuraEffectsByType(SPELL_AURA_MOD_DAMAGE_FROM_CASTER);