Core/Entities: Fixed an issue where creatures would not properly assist formation members in certain scenarios.

Port From (https://github.com/TrinityCore/TrinityCore/commit/00b9c23e28dc19a3a9f45d1d5b86d203f55b2a7e)

Source/Game/Combat/ThreatManager.cs

@@ -306,6 +306,10 @@ namespace Game.Combat
                 CreatureAI ownerAI = cOwner.GetAI();
                 if (ownerAI != null)
                     ownerAI.JustEngagedWith(target);
+
+                CreatureGroup formation = cOwner.GetFormation();
+                if (formation != null)
+                    formation.MemberEngagingTarget(cOwner, target);
             }
         }
 

Source/Game/Entities/Unit/Unit.Combat.cs

@@ -108,14 +108,6 @@ namespace Game.Entities
                 m_threatManager.AddThreat(enemy, 0.0f, null, true, true);
             else
                 SetInCombatWith(enemy);
-
-            Creature creature = ToCreature();
-            if (creature != null)
-            {
-                CreatureGroup formation = creature.GetFormation();
-                if (formation != null)
-                    formation.MemberEngagingTarget(creature, enemy);
-            }
         }
 
         public void ClearInCombat() { m_combatManager.EndAllCombat(); }