Core/Scripts: fix wrong uses of SetHitDamage hook.

This hook modifies damage AFTER it has been reduced by target auras/armor/resistances etc, it's useful if you want to scale damage by a factor, but not to add flat bonuses.
We're fixing those by moving calculation to Launch phase, where target taken bonuses haven't been used yet.

- Bronjahm: Magic's Bane
- BPC: Shadow Prison
- Oculus: Shock Lance
- Ymiron: Dark Slash (extra fix, it was wrongly damaging half of total health, it's supposed to be half of CURRENT health!)
- DK: Raise Ally Thrash spell (also extra fix: corrected formula)
- Warrior: Bloodthirst (shouldn't matter much as it's damage class none and those don't get bonuses by default)
- Warrior: Concussion Blow
- Warlock: extra fix for Haunt, healing part shouldn't scale with spell power

Closes #9560

(cherry picked from commit 9f5d1e2b10013e5fecf35fdd5af70921c96d07d1)

7 files changed, 43 insertions, 24 deletions

diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index c8c6329a5c0..e6c6116b0af 100644
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -4720,29 +4720,28 @@ uint32 Unit::GetDiseasesByCaster(ObjectGuid casterGUID, bool remove)
     static const AuraType diseaseAuraTypes[] =
     {
         SPELL_AURA_PERIODIC_DAMAGE, // Frost Fever and Blood Plague
-        SPELL_AURA_LINKED,          // Crypt Fever and Ebon Plague
-        SPELL_AURA_NONE
+        SPELL_AURA_LINKED           // Crypt Fever and Ebon Plague
     };
 
     uint32 diseases = 0;
-    for (AuraType const* itr = diseaseAuraTypes; *itr != SPELL_AURA_NONE; ++itr)
+    for (AuraType aType : diseaseAuraTypes)
     {
-        for (AuraEffectList::iterator i = m_modAuras[*itr].begin(); i != m_modAuras[*itr].end();)
+        for (auto itr = m_modAuras[aType].begin(); itr != m_modAuras[aType].end();)
         {
             // Get auras with disease dispel type by caster
-            if ((*i)->GetSpellInfo()->Dispel == DISPEL_DISEASE
-                && (*i)->GetCasterGUID() == casterGUID)
+            if ((*itr)->GetSpellInfo()->Dispel == DISPEL_DISEASE
+                && (*itr)->GetCasterGUID() == casterGUID)
             {
                 ++diseases;
 
                 if (remove)
                 {
-                    RemoveAura((*i)->GetId(), (*i)->GetCasterGUID());
-                    i = m_modAuras[*itr].begin();
+                    RemoveAura((*itr)->GetId(), (*itr)->GetCasterGUID());
+                    itr = m_modAuras[aType].begin();
                     continue;
                 }
             }
-            ++i;
+            ++itr;
         }
     }
     return diseases;
diff --git a/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_anubarak_trial.cpp b/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_anubarak_trial.cpp
index 36ceb9ed465..061344e2754 100644
--- a/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_anubarak_trial.cpp
+++ b/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_anubarak_trial.cpp
@@ -896,7 +896,7 @@ class spell_impale : public SpellScriptLoader
 
                 // make sure Impale doesnt do damage if we are standing on permafrost
                 if (target && target->HasAura(SPELL_PERMAFROST))
-                    SetHitDamage(0);
+                    PreventHitDamage();
             }
 
             void Register() override
diff --git a/src/server/scripts/Northrend/FrozenHalls/ForgeOfSouls/boss_bronjahm.cpp b/src/server/scripts/Northrend/FrozenHalls/ForgeOfSouls/boss_bronjahm.cpp
index 1367206bbb1..1fd1a8b4db5 100644
--- a/src/server/scripts/Northrend/FrozenHalls/ForgeOfSouls/boss_bronjahm.cpp
+++ b/src/server/scripts/Northrend/FrozenHalls/ForgeOfSouls/boss_bronjahm.cpp
@@ -268,20 +268,19 @@ class spell_bronjahm_magic_bane : public SpellScriptLoader
         {
             PrepareSpellScript(spell_bronjahm_magic_bane_SpellScript);
 
-            void RecalculateDamage()
+            void RecalculateDamage(SpellEffIndex /*effIndex*/)
             {
                 if (GetHitUnit()->GetPowerType() != POWER_MANA)
                     return;
 
                 int32 const maxDamage = GetCaster()->GetMap()->IsHeroic() ? 15000 : 10000;
-                int32 newDamage = GetHitDamage() + (GetHitUnit()->GetMaxPower(POWER_MANA) / 2);
-
-                SetHitDamage(std::min<int32>(maxDamage, newDamage));
+                int32 newDamage = GetEffectValue() + (GetHitUnit()->GetMaxPower(POWER_MANA) / 2);
+                SetEffectValue(std::min<int32>(maxDamage, newDamage));
             }
 
             void Register() override
             {
-                OnHit += SpellHitFn(spell_bronjahm_magic_bane_SpellScript::RecalculateDamage);
+                OnEffectLaunchTarget += SpellEffectFn(spell_bronjahm_magic_bane_SpellScript::RecalculateDamage, EFFECT_0, SPELL_EFFECT_SCHOOL_DAMAGE);
             }
         };
 
diff --git a/src/server/scripts/Northrend/IcecrownCitadel/boss_blood_prince_council.cpp b/src/server/scripts/Northrend/IcecrownCitadel/boss_blood_prince_council.cpp
index 024ed6b8731..2c3d8b68098 100644
--- a/src/server/scripts/Northrend/IcecrownCitadel/boss_blood_prince_council.cpp
+++ b/src/server/scripts/Northrend/IcecrownCitadel/boss_blood_prince_council.cpp
@@ -1497,16 +1497,16 @@ class spell_blood_council_shadow_prison_damage : public SpellScriptLoader
         {
             PrepareSpellScript(spell_blood_council_shadow_prison_SpellScript);
 
-            void AddExtraDamage()
+            void AddExtraDamage(SpellEffIndex /*effIndex*/)
             {
                 if (Aura* aur = GetHitUnit()->GetAura(GetSpellInfo()->Id))
                     if (AuraEffect const* eff = aur->GetEffect(EFFECT_1))
-                        SetHitDamage(GetHitDamage() + eff->GetAmount());
+                        SetEffectValue(GetEffectValue() + eff->GetAmount());
             }
 
             void Register() override
             {
-                OnHit += SpellHitFn(spell_blood_council_shadow_prison_SpellScript::AddExtraDamage);
+                OnEffectLaunchTarget += SpellEffectFn(spell_blood_council_shadow_prison_SpellScript::AddExtraDamage, EFFECT_0, SPELL_EFFECT_SCHOOL_DAMAGE);
             }
         };
 
diff --git a/src/server/scripts/Northrend/Nexus/Oculus/oculus.cpp b/src/server/scripts/Northrend/Nexus/Oculus/oculus.cpp
index 68f5ecc9ab2..f61ab9bf2b3 100644
--- a/src/server/scripts/Northrend/Nexus/Oculus/oculus.cpp
+++ b/src/server/scripts/Northrend/Nexus/Oculus/oculus.cpp
@@ -518,22 +518,24 @@ class spell_oculus_shock_lance : public SpellScriptLoader
                 return ValidateSpellInfo({ SPELL_AMBER_SHOCK_CHARGE });
             }
 
-            void CalcDamage()
+            void CalcDamage(SpellEffIndex /*effIndex*/)
             {
-                int32 damage = GetHitDamage();
+                int32 damage = GetEffectValue();
                 if (Unit* target = GetHitUnit())
+                {
                     if (AuraEffect const* shockCharges = target->GetAuraEffect(SPELL_AMBER_SHOCK_CHARGE, EFFECT_0, GetCaster()->GetGUID()))
                     {
                         damage += shockCharges->GetAmount();
-                        shockCharges->GetBase()->Remove();
+                        shockCharges->GetBase()->Remove(AURA_REMOVE_BY_ENEMY_SPELL);
                     }
+                }
 
-                SetHitDamage(damage);
+                SetEffectValue(damage);
             }
 
             void Register() override
             {
-                OnHit += SpellHitFn(spell_oculus_shock_lance_SpellScript::CalcDamage);
+                OnEffectLaunchTarget += SpellEffectFn(spell_oculus_shock_lance_SpellScript::CalcDamage, EFFECT_0, SPELL_EFFECT_SCHOOL_DAMAGE);
             }
         };
 
diff --git a/src/server/scripts/Northrend/UtgardeKeep/UtgardePinnacle/boss_ymiron.cpp b/src/server/scripts/Northrend/UtgardeKeep/UtgardePinnacle/boss_ymiron.cpp
index f0508e60b31..cfa74d6b59e 100644
--- a/src/server/scripts/Northrend/UtgardeKeep/UtgardePinnacle/boss_ymiron.cpp
+++ b/src/server/scripts/Northrend/UtgardeKeep/UtgardePinnacle/boss_ymiron.cpp
@@ -20,6 +20,7 @@
 #include "ObjectAccessor.h"
 #include "ScriptedCreature.h"
 #include "SpellInfo.h"
+#include "SpellScript.h"
 #include "TemporarySummon.h"
 #include "utgarde_pinnacle.h"
 
@@ -311,6 +312,23 @@ public:
     }
 };
 
+// 48292 - Dark Slash
+class spell_dark_slash : public SpellScript
+{
+    PrepareSpellScript(spell_dark_slash);
+
+    void CalculateDamage()
+    {
+        // Slashes the target with darkness, dealing damage equal to half the target's current health.
+        SetHitDamage(int32(ceil(GetHitUnit()->GetHealth() / 2.f)));
+    }
+
+    void Register() override
+    {
+        OnHit += SpellHitFn(spell_dark_slash::CalculateDamage);
+    }
+};
+
 class achievement_kings_bane : public AchievementCriteriaScript
 {
     public:
@@ -332,5 +350,6 @@ class achievement_kings_bane : public AchievementCriteriaScript
 void AddSC_boss_ymiron()
 {
     new boss_ymiron();
+    RegisterSpellScript(spell_dark_slash);
     new achievement_kings_bane();
 }
diff --git a/src/server/scripts/Outland/TempestKeep/Mechanar/boss_mechano_lord_capacitus.cpp b/src/server/scripts/Outland/TempestKeep/Mechanar/boss_mechano_lord_capacitus.cpp
index 62f5dc423f7..e48cc486797 100644
--- a/src/server/scripts/Outland/TempestKeep/Mechanar/boss_mechano_lord_capacitus.cpp
+++ b/src/server/scripts/Outland/TempestKeep/Mechanar/boss_mechano_lord_capacitus.cpp
@@ -209,7 +209,7 @@ class spell_capacitus_polarity_charge : public SpellScriptLoader
                 Unit* target = GetHitUnit();
 
                 if (target->HasAura(GetTriggeringSpell()->Id))
-                    SetHitDamage(0);
+                    PreventHitDamage();
             }
 
             void Register() override