Core/Spell: Fixed irregular handling of SPELLMOD_DOT

- Applied twice for some dots
- Missing for Health Leech Periodic
- Missing in a few scripts

Closes #17463

3 files changed, 42 insertions, 20 deletions

diff --git a/src/server/game/Spells/Auras/SpellAuraEffects.cpp b/src/server/game/Spells/Auras/SpellAuraEffects.cpp
index 48ca675991f..c7f89e1d242 100644
--- a/src/server/game/Spells/Auras/SpellAuraEffects.cpp
+++ b/src/server/game/Spells/Auras/SpellAuraEffects.cpp
@@ -5700,6 +5700,9 @@ void AuraEffect::HandlePeriodicHealthLeechAuraTick(Unit* target, Unit* caster) c
     else
         damage = std::max(int32(damage * GetDonePct()), 0);
 
+    if (Player* modOwner = caster->GetSpellModOwner())
+        modOwner->ApplySpellMod<SPELLMOD_DOT>(GetSpellInfo()->Id, damage);
+
     damage = target->SpellDamageBonusTaken(caster, GetSpellInfo(), damage, DOT, GetBase()->GetStackAmount());
 
     // Calculate armor mitigation
@@ -5711,12 +5714,14 @@ void AuraEffect::HandlePeriodicHealthLeechAuraTick(Unit* target, Unit* caster) c
     }
 
     if (!m_spellInfo->HasAttribute(SPELL_ATTR4_FIXED_DAMAGE))
+    {
         if (m_spellInfo->Effects[m_effIndex].IsTargetingArea() || isAreaAura)
         {
             damage = uint32(float(damage) * target->GetTotalAuraMultiplierByMiscMask(SPELL_AURA_MOD_AOE_DAMAGE_AVOIDANCE, m_spellInfo->SchoolMask));
             if (caster->GetTypeId() != TYPEID_PLAYER)
                 damage = uint32(float(damage) * target->GetTotalAuraMultiplierByMiscMask(SPELL_AURA_MOD_CREATURE_AOE_DAMAGE_AVOIDANCE, m_spellInfo->SchoolMask));
         }
+    }
 
     bool crit = false;
 
diff --git a/src/server/game/Spells/Auras/SpellAuras.cpp b/src/server/game/Spells/Auras/SpellAuras.cpp
index 39797269c2b..aec34948070 100644
--- a/src/server/game/Spells/Auras/SpellAuras.cpp
+++ b/src/server/game/Spells/Auras/SpellAuras.cpp
@@ -1293,20 +1293,27 @@ void Aura::HandleAuraSpecificMods(AuraApplication const* aurApp, Unit* caster, b
             case SPELLFAMILY_PRIEST:
                 if (!caster)
                     break;
+
                 // Devouring Plague
-                if (GetSpellInfo()->SpellFamilyFlags[0] & 0x02000000 && GetEffect(0))
+                if (GetSpellInfo()->SpellFamilyFlags[0] & 0x02000000)
                 {
+                    AuraEffect const* devouringPlague = GetEffect(EFFECT_0);
+                    if (!devouringPlague)
+                        break;
+
                     // Improved Devouring Plague
                     if (AuraEffect const* aurEff = caster->GetDummyAuraEffect(SPELLFAMILY_PRIEST, 3790, 1))
                     {
-                        uint32 damage = caster->SpellDamageBonusDone(target, GetSpellInfo(), GetEffect(0)->GetAmount(), DOT);
-                        damage *= caster->SpellDamagePctDone(target, GetSpellInfo(), SPELL_DIRECT_DAMAGE);
+                        int32 damage = (devouringPlague->GetAmount() + devouringPlague->GetBonusAmount()) * devouringPlague->GetDonePct();
+                        if (Player* modOwner = caster->GetSpellModOwner())
+                            modOwner->ApplySpellMod<SPELLMOD_DOT>(GetSpellInfo()->Id, damage);
+
                         damage = target->SpellDamageBonusTaken(caster, GetSpellInfo(), damage, DOT);
-                        int32 basepoints0 = aurEff->GetAmount() * GetEffect(0)->GetTotalTicks() * int32(damage) / 100;
-                        int32 heal = int32(CalculatePct(basepoints0, 15));
 
-                        caster->CastCustomSpell(target, 63675, &basepoints0, NULL, NULL, true, NULL, GetEffect(0));
-                        caster->CastCustomSpell(caster, 75999, &heal, NULL, NULL, true, NULL, GetEffect(0));
+                        int32 basepoints0 = CalculatePct(devouringPlague->GetTotalTicks() * static_cast<int32>(damage), aurEff->GetAmount());
+                        int32 heal = CalculatePct(basepoints0, 15);
+                        caster->CastCustomSpell(63675, SPELLVALUE_BASE_POINT0, basepoints0, target, true, nullptr, devouringPlague);
+                        caster->CastCustomSpell(75999, SPELLVALUE_BASE_POINT0, heal, (Unit*)nullptr, true, nullptr, devouringPlague);
                     }
                 }
                 // Power Word: Shield
diff --git a/src/server/game/Spells/SpellEffects.cpp b/src/server/game/Spells/SpellEffects.cpp
index c570d5fcf21..0bbd1a4f098 100644
--- a/src/server/game/Spells/SpellEffects.cpp
+++ b/src/server/game/Spells/SpellEffects.cpp
@@ -399,9 +399,9 @@ void Spell::EffectSchoolDMG(SpellEffIndex effIndex)
                 // Conflagrate - consumes Immolate or Shadowflame
                 else if (m_spellInfo->TargetAuraState == AURA_STATE_CONFLAGRATE)
                 {
-                    AuraEffect const* aura = NULL;                // found req. aura for damage calculation
+                    AuraEffect const* aura = nullptr;                // found req. aura for damage calculation
 
-                    Unit::AuraEffectList const &mPeriodic = unitTarget->GetAuraEffectsByType(SPELL_AURA_PERIODIC_DAMAGE);
+                    Unit::AuraEffectList const& mPeriodic = unitTarget->GetAuraEffectsByType(SPELL_AURA_PERIODIC_DAMAGE);
                     for (Unit::AuraEffectList::const_iterator i = mPeriodic.begin(); i != mPeriodic.end(); ++i)
                     {
                         // for caster applied auras only
@@ -424,15 +424,22 @@ void Spell::EffectSchoolDMG(SpellEffIndex effIndex)
                     // found Immolate or Shadowflame
                     if (aura)
                     {
-                        uint32 pdamage = uint32(std::max(aura->GetAmount(), 0));
-                        pdamage = m_caster->SpellDamageBonusDone(unitTarget, aura->GetSpellInfo(), pdamage, DOT, aura->GetBase()->GetStackAmount());
-                        pdamage = unitTarget->SpellDamageBonusTaken(m_caster, aura->GetSpellInfo(), pdamage, DOT, aura->GetBase()->GetStackAmount());
-                        uint32 pct_dir = m_caster->CalculateSpellDamage(unitTarget, m_spellInfo, (effIndex + 1));
-                        uint8 baseTotalTicks = uint8(m_caster->CalcSpellDuration(aura->GetSpellInfo()) / aura->GetSpellInfo()->Effects[EFFECT_0].Amplitude);
-                        damage += int32(CalculatePct(pdamage * baseTotalTicks, pct_dir));
+                        // Calculate damage of Immolate/Shadowflame tick
+                        int32 pdamage = (aura->GetAmount() + aura->GetBonusAmount()) * aura->GetDonePct();
+                        if (Player* modOwner = m_caster->GetSpellModOwner())
+                            modOwner->ApplySpellMod<SPELLMOD_DOT>(GetSpellInfo()->Id, pdamage);
+
+                        pdamage = unitTarget->SpellDamageBonusTaken(m_caster, aura->GetSpellInfo(), pdamage, DOT);
+
+                        // And multiply by amount of ticks to get damage potential
+                        pdamage *= aura->GetSpellInfo()->GetMaxTicks();
 
-                        uint32 pct_dot = m_caster->CalculateSpellDamage(unitTarget, m_spellInfo, (effIndex + 2)) / 3;
-                        m_spellValue->EffectBasePoints[1] = m_spellInfo->Effects[EFFECT_1].CalcBaseValue(int32(CalculatePct(pdamage * baseTotalTicks, pct_dot)));
+                        int32 pct_dir = m_caster->CalculateSpellDamage(unitTarget, m_spellInfo, EFFECT_1);
+                        damage += CalculatePct(pdamage, pct_dir);
+
+                        int32 pct_dot = m_caster->CalculateSpellDamage(unitTarget, m_spellInfo, EFFECT_2);
+                        int32 const dotBasePoints = CalculatePct(pdamage, pct_dot);
+                        m_spellValue->EffectBasePoints[EFFECT_1] = dotBasePoints / m_spellInfo->GetMaxTicks();
 
                         apply_direct_bonus = false;
                         // Glyph of Conflagrate
@@ -1397,9 +1404,12 @@ void Spell::EffectHeal(SpellEffIndex /*effIndex*/)
                 return;
             }
 
-            int32 tickheal = targetAura->GetAmount();
-            if (Unit* auraCaster = targetAura->GetCaster())
-                tickheal = auraCaster->SpellHealingBonusDone(unitTarget, targetAura->GetSpellInfo(), tickheal, DOT);
+            int32 tickheal = (targetAura->GetAmount() + targetAura->GetBonusAmount()) * targetAura->GetDonePct();
+            if (Player* modOwner = m_caster->GetSpellModOwner())
+                modOwner->ApplySpellMod<SPELLMOD_DOT>(targetAura->GetId(), tickheal);
+
+            unitTarget->SpellHealingBonusTaken(m_caster, targetAura->GetSpellInfo(), tickheal, DOT);
+
             //int32 tickheal = targetAura->GetSpellInfo()->EffectBasePoints[idx] + 1;
             //It is said that talent bonus should not be included