fix(Core/Spells): Fix Lock and Load procs (#24795)

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

data/sql/updates/pending_db_world/rev_1740153600000000000.sql

@@ -0,0 +1,3 @@
+-- Lock and Load: allow periodic tick procs (Black Arrow, Explosive Trap)
+-- SpellPhaseMask 6 = PROC_SPELL_PHASE_HIT | PROC_SPELL_PHASE_FINISH
+UPDATE `spell_proc` SET `SpellPhaseMask` = 6 WHERE `SpellId` = -56342;

src/server/game/Spells/Spell.cpp

@@ -719,6 +719,7 @@ Spell::~Spell()
 void Spell::InitExplicitTargets(SpellCastTargets const& targets)
 {
     m_targets = targets;
+    m_originalTargetGUID = targets.GetObjectTargetGUID();
     // this function tries to correct spell explicit targets for spell
     // client doesn't send explicit targets correctly sometimes - we need to fix such spells serverside
     // this also makes sure that we correctly send explicit targets to client (removes redundant data)
@@ -7855,6 +7856,11 @@ void Spell::DelayedChannel()
     SendChannelUpdate(m_timer);
 }
 
+Unit* Spell::GetOriginalTarget() const
+{
+    return ObjectAccessor::GetUnit(*m_caster, m_originalTargetGUID);
+}
+
 bool Spell::UpdatePointers()
 {
     if (m_originalCasterGUID == m_caster->GetGUID())

src/server/game/Spells/Spell.h

@@ -585,6 +585,7 @@ public:
 
     Unit* GetCaster() const { return m_caster; }
     Unit* GetOriginalCaster() const { return m_originalCaster; }
+    Unit* GetOriginalTarget() const;
     SpellInfo const* GetSpellInfo() const { return m_spellInfo; }
     int32 GetPowerCost() const { return m_powerCost; }
 
@@ -621,6 +622,8 @@ public:
     // e.g. damage around area spell trigered by victim aura and damage enemies of aura caster
     Unit* m_originalCaster;                             // cached pointer for m_originalCaster, updated at Spell::UpdatePointers()
 
+    ObjectGuid m_originalTargetGUID;                    // unit target saved before InitExplicitTargets strips it
+
     Spell** m_selfContainer;                            // pointer to our spell container (if applicable)
 
     std::string GetDebugInfo() const;

src/server/scripts/Spells/spell_hunter.cpp

@@ -67,6 +67,7 @@ enum HunterSpells
     SPELL_HUNTER_GLYPH_OF_ARCANE_SHOT               = 61389,
     SPELL_LOCK_AND_LOAD_TRIGGER                     = 56453,
     SPELL_LOCK_AND_LOAD_MARKER                      = 67544,
+    SPELL_FROST_TRAP_SLOW                           = 67035,
     SPELL_HUNTER_PET_LEGGINGS_OF_BEAST_MASTERY      = 38297, // Leggings of Beast Mastery
 
     // Proc system spells
@@ -1177,7 +1178,8 @@ class spell_hun_lock_and_load : public AuraScript
         return ValidateSpellInfo(
         {
             SPELL_LOCK_AND_LOAD_TRIGGER,
-            SPELL_LOCK_AND_LOAD_MARKER
+            SPELL_LOCK_AND_LOAD_MARKER,
+            SPELL_FROST_TRAP_SLOW
         });
     }
 
@@ -1197,6 +1199,13 @@ class spell_hun_lock_and_load : public AuraScript
         if (!spellInfo || !(spellInfo->GetSchoolMask() & (SPELL_SCHOOL_MASK_FROST | SPELL_SCHOOL_MASK_FIRE)))
             return false;
 
+        // TODO: Research whether Lock and Load should proc on targets
+        // immune to Frost Trap slow (bosses) in WotLK 3.3.5a.
+        // if (Spell const* procSpell = eventInfo.GetProcSpell())
+        //     if (Unit* target = procSpell->GetOriginalTarget())
+        //         if (target->IsImmunedToSpell(sSpellMgr->GetSpellInfo(SPELL_FROST_TRAP_SLOW)))
+        //             return false;
+
         return roll_chance_i(aurEff->GetAmount());
     }