fix(Core/Unit): Fix fast creatures chasing indefinitely (#21200)

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

@@ -10384,6 +10384,10 @@ bool Unit::Attack(Unit* victim, bool meleeAttack)
     if (meleeAttack)
         AddUnitState(UNIT_STATE_MELEE_ATTACKING);
 
+    // Update leash timer when attacking creatures
+    if (victim->IsCreature())
+        victim->ToCreature()->UpdateLeashExtensionTime();
+
     // set position before any AI calls/assistance
     //if (IsCreature())
     //    ToCreature()->SetCombatStartPosition(GetPositionX(), GetPositionY(), GetPositionZ());
@@ -10393,6 +10397,7 @@ bool Unit::Attack(Unit* victim, bool meleeAttack)
         SetInCombatWith(victim);
         if (victim->IsPlayer())
             victim->SetInCombatWith(this);
+
         AddThreat(victim, 0.0f);
 
         creature->SendAIReaction(AI_REACTION_HOSTILE);
@@ -13623,9 +13628,6 @@ void Unit::SetInCombatWith(Unit* enemy, uint32 duration)
         }
     }
 
-    if (Creature* pCreature = ToCreature())
-        pCreature->UpdateLeashExtensionTime();
-
     SetInCombatState(false, enemy, duration);
 }
 
@@ -13700,6 +13702,10 @@ void Unit::CombatStart(Unit* victim, bool initialAggro)
         SetInCombatWith(victim);
         victim->SetInCombatWith(this);
 
+        // Update leash timer when attacking creatures
+        if (victim->IsCreature())
+            victim->ToCreature()->UpdateLeashExtensionTime();
+
         // Xinef: If pet started combat - put owner in combat
         if (!alreadyInCombat && IsInCombat())
         {
@@ -13736,6 +13742,12 @@ void Unit::CombatStartOnCast(Unit* target, bool initialAggro, uint32 duration)
         // Xinef: If pet started combat - put owner in combat
         if (Unit* owner = GetOwner())
             owner->SetInCombatWith(target, duration);
+
+        // Update leash timer when attacking creatures
+        if (target->IsCreature())
+            target->ToCreature()->UpdateLeashExtensionTime();
+        else if (ToCreature()) // Reset leash if it is a spell caster, else it may evade inbetween casts
+            ToCreature()->UpdateLeashExtensionTime();
     }
 
     Unit* who = target->GetCharmerOrOwnerOrSelf();