Core/Vehicles:

- Set MovementFlagsExtra (2) correctly depending on vehicle 'template' flags. This makes certain vehicles such as demolishers unable to jump/strafe (as intended)
- Fix SMSG_MONSTER_MOVE_TRANSPORT stucture, prevents a client crash when entering certain vehicles, as well as *properly* broadcast position relative to the vehicle.
- Send SMSG_BREAK_TARGET to player when entering vehicle.
- Set MOVEMENTFLAG_ROOT on passenger when entering vehicle
- Cleanup in affected code

src/server/game/Entities/Vehicle/Vehicle.cpp

@@ -317,7 +317,7 @@ bool Vehicle::AddPassenger(Unit *unit, int8 seatId, bool byAura)
     if (seat->second.seatInfo->m_flags && !(seat->second.seatInfo->m_flags & VEHICLE_SEAT_FLAG_UNK11))
         unit->AddUnitState(UNIT_STAT_ONVEHICLE);
 
-    unit->AddUnitMovementFlag(MOVEMENTFLAG_ONTRANSPORT);
+    unit->AddUnitMovementFlag(MOVEMENTFLAG_ONTRANSPORT | MOVEMENTFLAG_ROOT);
     VehicleSeatEntry const *veSeat = seat->second.seatInfo;
     unit->m_movementInfo.t_pos.m_positionX = veSeat->m_attachmentOffsetX;
     unit->m_movementInfo.t_pos.m_positionY = veSeat->m_attachmentOffsetY;
@@ -449,3 +449,23 @@ void Vehicle::Dismiss()
     me->CombatStop();
     me->AddObjectToRemoveList();
 }
+
+uint16 Vehicle::GetExtraMovementFlagsForBase() const
+{
+    uint16 movementMask = MOVEMENTFLAG2_NONE;
+    uint32 vehicleFlags = GetVehicleInfo()->m_flags;
+
+    if (vehicleFlags & VEHICLE_FLAG_NO_STRAFE)
+        movementMask |= MOVEMENTFLAG2_NO_STRAFE;
+    if (vehicleFlags & VEHICLE_FLAG_NO_JUMPING)
+        movementMask |= MOVEMENTFLAG2_NO_JUMPING;
+    if (vehicleFlags & VEHICLE_FLAG_FULLSPEEDTURNING)
+        movementMask |= MOVEMENTFLAG2_FULL_SPEED_TURNING;
+    if (vehicleFlags & VEHICLE_FLAG_ALLOW_PITCHING)
+        movementMask |= MOVEMENTFLAG2_ALWAYS_ALLOW_PITCHING;
+    if (vehicleFlags & VEHICLE_FLAG_FULLSPEEDPITCHING)
+        movementMask |= MOVEMENTFLAG2_FULL_SPEED_PITCHING;
+
+    sLog->outDebug("Vehicle::GetExtraMovementFlagsForBase() returned %u", movementMask);
+    return movementMask;
+}