Core/Movement: Fix players still able to fly on SPELL_AURA_FLY and SPELL_AURA_MOD_INCREASE_MOUNTED_FLIGHT_SPEED unapply.

Closes #5731

src/server/game/Entities/Player/Player.cpp

@@ -25173,3 +25173,21 @@ bool Player::SetHover(bool enable)
 
     return true;
 }
+
+void Player::SendMovementSetCanFly(bool apply)
+{
+    WorldPacket data(apply ? SMSG_MOVE_SET_CAN_FLY : SMSG_MOVE_UNSET_CAN_FLY, 12);
+    data.append(GetPackGUID());
+    data << uint32(0);          //! movement counter
+    SendDirectMessage(&data);
+}
+
+void Player::SendMovementSetCanTransitionBetweenSwimAndFly(bool apply)
+{
+    WorldPacket data(apply ? 
+        SMSG_MOVE_SET_CAN_TRANSITION_BETWEEN_SWIM_AND_FLY : 
+        SMSG_MOVE_UNSET_CAN_TRANSITION_BETWEEN_SWIM_AND_FLY, 12);
+    data.append(GetPackGUID());
+    data << uint32(0);          //! movement counter
+    SendDirectMessage(&data);
+}

src/server/game/Entities/Player/Player.h

@@ -2483,6 +2483,13 @@ class Player : public Unit, public GridObject<Player>
 
         #pragma region Player Movement
 
+                
+        /*! These methods send different packets to the client in apply and unapply case.
+            These methods are only sent to the current unit.
+        */
+        void SendMovementSetCanFly(bool apply);
+        void SendMovementSetCanTransitionBetweenSwimAndFly(bool apply);
+
         bool CanFly() const { return m_movementInfo.HasMovementFlag(MOVEMENTFLAG_CAN_FLY); }
 
         //! Return collision height sent to client

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

@@ -17541,3 +17541,36 @@ void Unit::SendMovementFeatherFall()
     BuildMovementPacket(&data);
     SendMessageToSet(&data, true);
 }
+    
+void Unit::SendMovementGravityChange()
+{
+    WorldPacket data(MSG_MOVE_GRAVITY_CHNG, 64);
+    data.append(GetPackGUID());
+    BuildMovementPacket(&data);
+    SendMessageToSet(&data, true);
+}
+
+void Unit::SendMovementCanFlyChange()
+{
+    /*!
+        if ( a3->MoveFlags & MOVEMENTFLAG_CAN_FLY )
+        {
+            v4->MoveFlags |= 0x1000000u;
+            result = 1;
+        }
+        else
+        {
+            if ( v4->MoveFlags & MOVEMENTFLAG_FLYING )
+                CMovement::DisableFlying(v4);
+            v4->MoveFlags &= 0xFEFFFFFFu;
+            result = 1;
+        }
+    */
+    if (GetTypeId() == TYPEID_PLAYER)
+        ToPlayer()->SendMovementSetCanFly(CanFly());
+
+    WorldPacket data(MSG_MOVE_UPDATE_CAN_FLY, 64);
+    data.append(GetPackGUID());
+    BuildMovementPacket(&data);
+    SendMessageToSet(&data, true);
+}

src/server/game/Entities/Unit/Unit.h

@@ -1631,9 +1631,18 @@ class Unit : public WorldObject
         //void SendMonsterMove(float NewPosX, float NewPosY, float NewPosZ, uint8 type, uint32 MovementFlags, uint32 Time, Player* player = NULL);
         void SendMonsterMoveTransport(Unit* vehicleOwner);
         void SendMovementFlagUpdate();
+
+        /*! These methods send the same packet to the client in apply and unapply case.
+            The client-side interpretation of this packet depends on the presence of relevant movementflags
+            which are sent with movementinfo. Furthermore, these packets are broadcast to nearby players as well
+            as the current unit. 
+        */
         void SendMovementHover();
         void SendMovementFeatherFall();
         void SendMovementWaterWalking();
+        void SendMovementGravityChange();
+        void SendMovementCanFlyChange();
+
         bool IsLevitating() const { return m_movementInfo.HasMovementFlag(MOVEMENTFLAG_DISABLE_GRAVITY);}
         bool IsWalking() const { return m_movementInfo.HasMovementFlag(MOVEMENTFLAG_WALKING);}
         virtual bool SetWalk(bool enable);

src/server/game/Spells/Auras/SpellAuraEffects.cpp

@@ -2844,21 +2844,14 @@ void AuraEffect::HandleAuraAllowFlight(AuraApplication const* aurApp, uint8 mode
             return;
     }
 
-    if (target->GetTypeId() == TYPEID_UNIT)
-        target->SetCanFly(apply);
+    //! Not entirely sure if this should be sent for creatures as well, but I don't think so.
+    target->SetCanFly(apply);
+    Player* player = target->ToPlayer();
+    if (!player)
+        player = target->m_movedPlayer;
 
-    if (Player* player = target->m_movedPlayer)
-    {
-        // allow flying
-        WorldPacket data;
-        if (apply)
-            data.Initialize(SMSG_MOVE_SET_CAN_FLY, 12);
-        else
-            data.Initialize(SMSG_MOVE_UNSET_CAN_FLY, 12);
-        data.append(target->GetPackGUID());
-        data << uint32(0);                                      // movement counter
-        player->SendDirectMessage(&data);
-    }
+    if (player)
+        player->SendMovementCanFlyChange();
 }
 
 void AuraEffect::HandleAuraWaterWalk(AuraApplication const* aurApp, uint8 mode, bool apply) const
@@ -3231,25 +3224,22 @@ void AuraEffect::HandleAuraModIncreaseFlightSpeed(AuraApplication const* aurApp,
 
     Unit* target = aurApp->GetTarget();
 
-    // Enable Fly mode for flying mounts
+    //! Update ability to fly 
     if (GetAuraType() == SPELL_AURA_MOD_INCREASE_MOUNTED_FLIGHT_SPEED)
     {
         // do not remove unit flag if there are more than this auraEffect of that kind on unit on unit
         if (mode & AURA_EFFECT_HANDLE_SEND_FOR_CLIENT_MASK && (apply || (!target->HasAuraType(SPELL_AURA_MOD_INCREASE_MOUNTED_FLIGHT_SPEED) && !target->HasAuraType(SPELL_AURA_FLY))))
         {
-            if (Player* player = target->m_movedPlayer)
-            {
-                WorldPacket data;
-                if (apply)
-                    data.Initialize(SMSG_MOVE_SET_CAN_FLY, 12);
-                else
-                    data.Initialize(SMSG_MOVE_UNSET_CAN_FLY, 12);
-                data.append(player->GetPackGUID());
-                data << uint32(0);                                      // unknown
-                player->SendDirectMessage(&data);
-            }
+            target->SetCanFly(apply);
+            Player* player = target->ToPlayer();
+            if (!player)
+                player = target->m_movedPlayer;
+
+            if (player)
+                player->SendMovementCanFlyChange();
         }
 
+        //! Someone should clean up these hacks and remove it from this function. It doesn't even belong here.
         if (mode & AURA_EFFECT_HANDLE_REAL)
         {
             //Players on flying mounts must be immune to polymorph