fix(Core/Unit): correct partial school immunity for dual-school spells (#26254)

src/server/game/Entities/Unit/Unit.cpp

@@ -939,34 +939,8 @@ bool Unit::IsImmunedToSpell(SpellInfo const* spellInfo, uint32 effectMask, Unit
     if (hasCheckedEffect && immuneToAllEffects)
         return true;
 
-    if (!spellInfo->HasAttribute(SPELL_ATTR2_NO_SCHOOL_IMMUNITIES))
+    if (!spellInfo->HasAttribute(SPELL_ATTR2_NO_SCHOOL_IMMUNITIES) && HasSchoolImmunityForMask(spellInfo->GetSchoolMask(), caster, spellInfo))
-    {
-        if (spellInfo->Id == 42292 || spellInfo->Id == 59752 || spellInfo->Id == 19574 || spellInfo->Id == 34471)
-            return false;
-
-        SpellSchoolMask schoolMask = spellInfo->GetSchoolMask();
-        if (schoolMask != SPELL_SCHOOL_MASK_NONE)
-        {
-            SpellImmuneContainer const& schoolList = m_spellImmune[IMMUNITY_SCHOOL];
-            for (auto const& [immunitySchoolMask, immunityAuraId] : schoolList)
-            {
-                SpellInfo const* immuneSpellInfo = sSpellMgr->GetSpellInfo(immunityAuraId);
-                if (immunityAuraId == spellInfo->Id)
-                    continue;
-
-                if ((immunitySchoolMask & schoolMask) != schoolMask)
-                    continue;
-
-                if (IgnoresSchoolImmunityFromFriendlyCaster(caster, immunityAuraId, immuneSpellInfo))
-                    continue;
-
-                if (spellInfo->CanPierceImmuneAura(immuneSpellInfo))
-                    continue;
-
         return true;
-            }
-        }
-    }
 
     return false;
 }
@@ -9860,6 +9834,32 @@ bool Unit::IgnoresSchoolImmunityFromFriendlyCaster(Unit const* caster, uint32 im
     return immunityAuraId == std::numeric_limits<uint32>::max();
 }
 
+bool Unit::HasSchoolImmunityForMask(SpellSchoolMask schoolMask, Unit const* caster, SpellInfo const* spellInfo) const
+{
+    if (schoolMask == SPELL_SCHOOL_MASK_NONE)
+        return false;
+
+    uint32 accumulatedMask = 0;
+    for (auto const& [immunitySchoolMask, immunityAuraId] : m_spellImmune[IMMUNITY_SCHOOL])
+    {
+        // Skip the spell's own immunity entry
+        if (spellInfo && immunityAuraId == spellInfo->Id)
+            continue;
+
+        SpellInfo const* immuneSpellInfo = sSpellMgr->GetSpellInfo(immunityAuraId);
+
+        if (IgnoresSchoolImmunityFromFriendlyCaster(caster, immunityAuraId, immuneSpellInfo))
+            continue;
+
+        if (spellInfo && immuneSpellInfo && spellInfo->CanPierceImmuneAura(immuneSpellInfo))
+            continue;
+
+        accumulatedMask |= immunitySchoolMask;
+    }
+
+    return (SpellSchoolMask(accumulatedMask) & schoolMask) == schoolMask;
+}
+
 bool Unit::IsImmunedToDamage(SpellSchoolMask schoolMask) const
 {
     if (schoolMask == SPELL_SCHOOL_MASK_NONE)
@@ -9935,68 +9935,10 @@ bool Unit::IsImmunedToSchool(SpellSchoolMask schoolMask) const
     });
 }
 
-bool Unit::IsImmunedToSchool(SpellInfo const* spellInfo) const
-{
-    if (spellInfo->HasAttribute(SPELL_ATTR0_NO_IMMUNITIES) && !HasSpiritOfRedemptionAura())
-        return false;
-
-    uint32 schoolMask = spellInfo->GetSchoolMask();
-    if (schoolMask == SPELL_SCHOOL_MASK_NONE)
-    {
-        return false;
-    }
-
-    if (spellInfo->Id != 42292 && spellInfo->Id != 59752 && spellInfo->Id != 19574 && spellInfo->Id != 34471)
-    {
-        // Check IMMUNITY_SCHOOL: returns true if ALL schools in the mask are covered and spell can't pierce
-        SpellImmuneContainer const& schoolList = m_spellImmune[IMMUNITY_SCHOOL];
-        for (auto itr = schoolList.begin(); itr != schoolList.end(); ++itr)
-            if ((itr->first & schoolMask) == schoolMask && !spellInfo->CanPierceImmuneAura(sSpellMgr->GetSpellInfo(itr->second)))
-                return true;
-    }
-
-    return false;
-}
-
-bool Unit::IsImmunedToSchool(Spell const* spell) const
-{
-    SpellInfo const* spellInfo = spell->GetSpellInfo();
-    if (spellInfo->HasAttribute(SPELL_ATTR0_NO_IMMUNITIES) && !HasSpiritOfRedemptionAura())
-    {
-        return false;
-    }
-
-    uint32 schoolMask = spell->GetSpellSchoolMask();
-    if (schoolMask == SPELL_SCHOOL_MASK_NONE)
-    {
-        return false;
-    }
-
-    if (spellInfo->Id != 42292 && spellInfo->Id != 59752 && spellInfo->Id != 19574 && spellInfo->Id != 34471)
-    {
-        // Check IMMUNITY_SCHOOL: returns true if ALL schools in the mask are covered and spell can't pierce
-        SpellImmuneContainer const& schoolList = m_spellImmune[IMMUNITY_SCHOOL];
-        for (auto itr = schoolList.begin(); itr != schoolList.end(); ++itr)
-        {
-            SpellInfo const* immuneSpellInfo = sSpellMgr->GetSpellInfo(itr->second);
-            if ((itr->first & schoolMask) == schoolMask
-                && !IgnoresSchoolImmunityFromFriendlyCaster(spell->GetCaster(), itr->second, immuneSpellInfo)
-                && !spellInfo->CanPierceImmuneAura(immuneSpellInfo))
-            {
-                return true;
-            }
-        }
-    }
-
-    return false;
-}
-
 bool Unit::IsImmunedToDamageOrSchool(SpellSchoolMask schoolMask) const
 {
     if (schoolMask == SPELL_SCHOOL_MASK_NONE)
-    {
         return false;
-    }
 
     return IsImmunedToDamage(schoolMask) || IsImmunedToSchool(schoolMask);
 }
@@ -10102,28 +10044,9 @@ bool Unit::IsImmunedToSpell(SpellInfo const* spellInfo, Unit const* caster, Spel
 
     if (!spellInfo->HasAttribute(SPELL_ATTR2_NO_SCHOOL_IMMUNITIES))
     {
-        if (spellSchoolMask != SPELL_SCHOOL_MASK_NONE)
+        if (HasSchoolImmunityForMask(spellSchoolMask, caster, spellInfo))
-        {
-            SpellImmuneContainer const& schoolList = m_spellImmune[IMMUNITY_SCHOOL];
-            for (auto itr = schoolList.begin(); itr != schoolList.end(); ++itr)
-            {
-                if (itr->second == spellInfo->Id)
-                    continue;
-
-                SpellInfo const* immuneSpellInfo = sSpellMgr->GetSpellInfo(itr->second);
-                if (!(itr->first & spellSchoolMask))
-                    continue;
-
-                if (IgnoresSchoolImmunityFromFriendlyCaster(caster, itr->second, immuneSpellInfo))
-                    continue;
-
-                if (spellInfo->CanPierceImmuneAura(immuneSpellInfo))
-                    continue;
-
             return true;
     }
-        }
-    }
 
     return false;
 }

src/server/game/Entities/Unit/Unit.h

@@ -1645,14 +1645,13 @@ public:
     [[nodiscard]] bool IsImmunedToDamage(SpellSchoolMask schoolMask) const;
     [[nodiscard]] bool IsImmunedToDamage(Unit const* caster, SpellInfo const* spellInfo) const;
     [[nodiscard]] bool IsImmunedToSchool(SpellSchoolMask schoolMask) const;
+    [[nodiscard]] bool HasSchoolImmunityForMask(SpellSchoolMask schoolMask, Unit const* caster, SpellInfo const* spellInfo) const;
 
     static bool IsImmuneMaskFully(SpellSchoolMask immuneMask, SpellSchoolMask schoolMask) { return (immuneMask & schoolMask) == schoolMask; }
 
     [[nodiscard]] uint32 GetSchoolImmunityMask() const;
     [[nodiscard]] uint32 GetDamageImmunityMask() const;
 
-    [[nodiscard]] bool IsImmunedToSchool(SpellInfo const* spellInfo) const;
-    [[nodiscard]] bool IsImmunedToSchool(Spell const* spell) const;
     [[nodiscard]] bool IsImmunedToDamageOrSchool(SpellSchoolMask schoolMask) const;
     [[nodiscard]] bool IsImmunedToAuraPeriodicTick(Unit const* caster, SpellInfo const* spellInfo) const;
     virtual bool IsImmunedToSpellEffect(SpellInfo const* spellInfo, uint32 index, Unit const* caster = nullptr) const;

src/server/game/Spells/Spell.cpp

@@ -2982,7 +2982,7 @@ SpellMissInfo Spell::DoSpellHitOnUnit(Unit* unit, uint32 effectMask, bool scaleA
         return SPELL_MISS_EVADE;
 
     // For delayed spells immunity may be applied between missile launch and hit - check immunity for that case
-    if (m_spellInfo->Speed && ((m_damage > 0 && unit->IsImmunedToDamage(m_caster, m_spellInfo)) || unit->IsImmunedToSchool(this) || unit->IsImmunedToSpell(m_spellInfo, this)))
+    if (m_spellInfo->Speed && ((m_damage > 0 && unit->IsImmunedToDamage(m_caster, m_spellInfo)) || unit->IsImmunedToSpell(m_spellInfo, this)))
     {
         return SPELL_MISS_IMMUNE;
     }

src/server/game/Spells/SpellInfoCorrections.cpp

@@ -5202,6 +5202,16 @@ void SpellMgr::LoadSpellInfoCorrections()
         spellInfo->Effects[EFFECT_0].BasePoints = 1;
     });
 
+    ApplySpellFix({
+        42292,  // PvP Trinket
+        59752,  // Every Man for Himself
+        19574,  // Bestial Wrath
+        34471   // The Beast Within
+        }, [](SpellInfo* spellInfo)
+    {
+        spellInfo->AttributesEx2 |= SPELL_ATTR2_NO_SCHOOL_IMMUNITIES;
+    });
+
     // 51036 Summon Venture Co. Air Patrol
     ApplySpellFix({ 51036 }, [](SpellInfo* spellInfo)
     {