fix(Core/Scripts): Fix Missile Barrage and Clearcasting proc with Arcane Missiles (#24958)

Co-authored-by: blinkysc <blinkysc@users.noreply.github.com>

data/sql/updates/pending_db_world/rev_1772406444785733446.sql

@@ -0,0 +1,9 @@
+-- Fix Missile Barrage / Clearcasting proc interaction with Arcane Missiles
+-- 1) PROC_ATTR_REQ_SPELLMOD was incorrectly blocking Missile Barrage from
+--    proccing because the channel spell (42846) is not in m_appliedMods.
+--    Restrict via SpellFamilyMask to Arcane Missiles (0x800) instead.
+-- 2) Register Clearcasting script to give Missile Barrage priority
+UPDATE `spell_proc` SET `AttributesMask` = 0, `SpellFamilyMask0` = 0x800 WHERE `SpellId` = 44401;
+
+DELETE FROM `spell_script_names` WHERE `spell_id` = 12536 AND `ScriptName` = 'spell_mage_clearcasting';
+INSERT INTO `spell_script_names` (`spell_id`, `ScriptName`) VALUES (12536, 'spell_mage_clearcasting');

src/server/game/Entities/Player/Player.cpp

@@ -10027,9 +10027,10 @@ bool Player::HasSpellModApplied(SpellModifier* mod, Spell* spell)
 
 void Player::SetSpellModTakingSpell(Spell* spell, bool apply)
 {
-    if (apply && m_spellModTakingSpell && m_spellModTakingSpell != spell)
+    if (apply && m_spellModTakingSpell != nullptr)
         return;
-    else if (!apply && m_spellModTakingSpell != spell)
+
+    if (!apply && (!m_spellModTakingSpell || m_spellModTakingSpell != spell))
         return;
 
     m_spellModTakingSpell = apply ? spell : nullptr;

src/server/game/Spells/Spell.cpp

@@ -3911,9 +3911,6 @@ void Spell::_cast(bool skipCheck)
     // we must send smsg_spell_go packet before m_castItem delete in TakeCastItem()...
     SendSpellGo();
 
-    if (modOwner)
-        modOwner->SetSpellModTakingSpell(this, true);
-
     bool resetAttackTimers = IsAutoActionResetSpell() && !m_spellInfo->HasAttribute(SPELL_ATTR2_DO_NOT_RESET_COMBAT_TIMERS);
     if (resetAttackTimers)
     {

src/server/scripts/Spells/spell_mage.cpp

@@ -71,7 +71,8 @@ enum MageSpells
     SPELL_MAGE_CHILLED_R3                        = 12486,
     SPELL_MAGE_MANA_SURGE                        = 37445,
     SPELL_MAGE_FROST_NOVA                        = 122,
-    SPELL_MAGE_LIVING_BOMB_R1                    = 44457
+    SPELL_MAGE_LIVING_BOMB_R1                    = 44457,
+    SPELL_MAGE_MISSILE_BARRAGE_PROC              = 44401
 };
 
 enum MageSpellIcons
@@ -1504,6 +1505,31 @@ class spell_mage_ice_block : public SpellScript
     }
 };
 
+// 12536 - Clearcasting
+class spell_mage_clearcasting : public AuraScript
+{
+    PrepareAuraScript(spell_mage_clearcasting);
+
+    bool CheckProc(ProcEventInfo& eventInfo)
+    {
+        SpellInfo const* spellInfo = eventInfo.GetSpellInfo();
+        if (!spellInfo)
+            return true;
+
+        // Missile Barrage has priority over Clearcasting for Arcane Missiles
+        if (spellInfo->SpellFamilyName == SPELLFAMILY_MAGE && (spellInfo->SpellFamilyFlags[0] & 0x800))
+            if (GetTarget()->HasAura(SPELL_MAGE_MISSILE_BARRAGE_PROC))
+                return false;
+
+        return true;
+    }
+
+    void Register() override
+    {
+        DoCheckProc += AuraCheckProcFn(spell_mage_clearcasting::CheckProc);
+    }
+};
+
 // 44401 - Missile Barrage (proc buff)
 class spell_mage_missile_barrage_proc : public AuraScript
 {
@@ -1575,6 +1601,7 @@ void AddSC_mage_spell_scripts()
     RegisterSpellScript(spell_mage_ice_block);
     RegisterSpellScript(spell_mage_imp_blizzard);
     RegisterSpellScript(spell_mage_imp_mana_gems);
+    RegisterSpellScript(spell_mage_clearcasting);
     RegisterSpellScript(spell_mage_missile_barrage);
     RegisterSpellScript(spell_mage_missile_barrage_proc);
     RegisterSpellScript(spell_mage_blast_wave);