Reading discrete inputs or coils doesn't work because QModbusClientPrivate::collateBits() throws away the results.

After receiving a response PDU for Read Coils/ Read Discrete Inputs, QModbusClientPrivate::collateBits() should call setValues() on the QModbusDataUnit to set the result. Instead, the function calls setValue() for each bit, which promptly discards the result because the m_values vector is empty.

A workaround is to manually call setValues() with the expected number of bits before the request is processed.