Using a scattered register map breaks QModbusServer

QModbusServer only supports subsequent data unit register addresses. If one tries to add multiple ranges of values, the current implementation breaks and fails to read/write data units.

My current workaround: Sub-class QModbusServer and implement separate data unit storages, one for each register type. I've introduced a new method called initDataUnit(), which I use iso. setMap(). I'd suggest implementing something similar in Qt in order to support scattered register maps.

typedef QMap<int, QModbusDataUnit> RegisterMap;

class MyModbusServer : public QModbusServer {
{
//...

public:
    bool setMap(...) { return false; }

    void initDataUnit(const QModbusDataUnit &dataUnit) { /* add unit to one of the maps */ }

protected:
    bool writeData(...) { ... }
    bool readData(...) { ... }
 

private:
    RegisterMap m_coils;
    RegisterMap m_discrete_input;
    RegisterMap m_input_registers;
    RegisterMap m_holding_registers;
}