fix(Core): [Spell][Night Elf] Shadowmeld is not working properly (#4765)

data/sql/updates/pending_db_world/rev_1615287196510790727.sql

@@ -0,0 +1,8 @@
+INSERT INTO `version_db_world` (`sql_rev`) VALUES ('1615287196510790727');
+
+-- Delete spell_linked_spell  for Shadowmeld
+DELETE FROM `spell_linked_spell` WHERE `spell_trigger` IN (58984);
+
+-- Fix Shadowmeld
+DELETE FROM `spell_script_names` WHERE `ScriptName` = 'spell_gen_shadowmeld';
+INSERT INTO `spell_script_names` VALUES (58984, 'spell_gen_shadowmeld');

src/server/scripts/Spells/spell_generic.cpp

@@ -5041,6 +5041,63 @@ public:
     }
 };
 
+class spell_gen_shadowmeld : public SpellScriptLoader
+{
+public:
+    spell_gen_shadowmeld() : SpellScriptLoader("spell_gen_shadowmeld") {}
+
+    class spell_gen_shadowmeld_SpellScript : public SpellScript
+    {
+        PrepareSpellScript(spell_gen_shadowmeld_SpellScript);
+
+        void HandleDummy(SpellEffIndex /*effIndex*/)
+        {
+            Unit* caster = GetCaster();
+            if (!caster)
+                return;
+
+            caster->InterruptSpell(CURRENT_AUTOREPEAT_SPELL); // break Auto Shot and autohit
+            caster->InterruptSpell(CURRENT_CHANNELED_SPELL); // break channeled spells
+
+            bool instant_exit = true;
+            if (Player* pCaster = caster->ToPlayer()) // if is a creature instant exits combat, else check if someone in party is in combat in visibility distance
+            {
+                uint64 myGUID = pCaster->GetGUID();
+                float visibilityRange = pCaster->GetMap()->GetVisibilityRange();
+                if (Group* pGroup = pCaster->GetGroup())
+                {
+                    const Group::MemberSlotList membersList = pGroup->GetMemberSlots();
+                    for (Group::member_citerator itr = membersList.begin(); itr != membersList.end() && instant_exit; ++itr)
+                        if (itr->guid != myGUID)
+                            if (Player* GroupMember = ObjectAccessor::GetPlayer(*pCaster, itr->guid))
+                                if (GroupMember->IsInCombat() && pCaster->GetMap() == GroupMember->GetMap() && pCaster->IsWithinDistInMap(GroupMember, visibilityRange))
+                                    instant_exit = false;
+                }
+
+                pCaster->SendAttackSwingCancelAttack();
+            }
+
+            if (!caster->GetInstanceScript() || !caster->GetInstanceScript()->IsEncounterInProgress()) //Don't leave combat if you are in combat with a boss
+            {
+                if (!instant_exit) {
+                    caster->getHostileRefManager().deleteReferences(); // exit combat after 6 seconds
+                }
+                else caster->CombatStop(); // isn't necessary to call AttackStop because is just called in CombatStop
+            }
+        }
+
+        void Register() override
+        {
+            OnEffectHitTarget += SpellEffectFn(spell_gen_shadowmeld_SpellScript::HandleDummy, EFFECT_1, SPELL_EFFECT_DUMMY);
+        }
+    };
+
+    SpellScript* GetSpellScript() const override
+    {
+        return new spell_gen_shadowmeld_SpellScript();
+    }
+};
+
 void AddSC_generic_spell_scripts()
 {
     // ours:
@@ -5170,4 +5227,5 @@ void AddSC_generic_spell_scripts()
     new spell_gen_eject_all_passengers();
     new spell_gen_eject_passenger();
     new spell_gen_charmed_unit_spell_cooldown();
+    new spell_gen_shadowmeld();
 }