Core/Units: Allow autoattack if channelling with SPELL_ATTR5_ALLOW_ACTIONS_DURING_CHANNEL

Port From (https://github.com/TrinityCore/TrinityCore/commit/bbe7cba7f411977d756f6f697056aafb920a5b0a)

Source/Framework/Constants/UnitConst.cs

@@ -500,7 +500,7 @@ namespace Framework.Constants
         Moving = RoamingMove | ConfusedMove | FleeingMove | ChaseMove | FollowMove | FollowFormationMove,
         Controlled = Confused | Stunned | Fleeing,
         LostControl = Controlled | Possessed | Jumping | Charging,
-        CannotAutoattack = Controlled | Charging | Casting,
+        CannotAutoattack = Controlled | Charging,
         Sightless = LostControl | Evade,
         CannotTurn = LostControl | Rotating | Focusing,
         NotMove = Root | Stunned | Died | Distracted,

Source/Game/AI/CoreAI/UnitAI.cs

@@ -54,9 +54,16 @@ namespace Game.AI
 
         public void DoMeleeAttackIfReady()
         {
-            if (me.HasUnitState(UnitState.Casting) || (me.IsCreature() && !me.ToCreature().CanMelee()))
+            if (me.IsCreature() && !me.ToCreature().CanMelee())
                 return;
 
+            if (me.HasUnitState(UnitState.Casting))
+            {
+                Spell channeledSpell = me.GetCurrentSpell(CurrentSpellTypes.Channeled);
+                if (channeledSpell == null || !channeledSpell.GetSpellInfo().HasAttribute(SpellAttr5.AllowActionsDuringChannel))
+                    return;
+            }
+
             Unit victim = me.GetVictim();
 
             if (!me.IsWithinMeleeRange(victim))

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

@@ -506,6 +506,13 @@ namespace Game.Entities
             if (HasUnitState(UnitState.CannotAutoattack) && !extra)
                 return;
 
+            if (HasUnitState(UnitState.Casting))
+            {
+                Spell channeledSpell = GetCurrentSpell(CurrentSpellTypes.Channeled);
+                if (channeledSpell == null || !channeledSpell.GetSpellInfo().HasAttribute(SpellAttr5.AllowActionsDuringChannel))
+                    return;
+            }
+
             if (HasAuraType(AuraType.DisableAttackingExceptAbilities))
                 return;