Method gcode_line_error

Marlin/src/gcode/queue.cpp:320–327

#endif // (ARDUINO_ARCH_STM32F4 || ARDUINO_ARCH_STM32) && USBCON

void GCodeQueue::gcode_line_error(FSTR_P const ferr, const serial_index_t serial_ind) {
  PORT_REDIRECT(SERIAL_PORTMASK(serial_ind)); // Reply to the serial port that sent the command
  SERIAL_ERROR_START();
  SERIAL_ECHOLN(ferr, serial_state[serial_ind.index].last_N);
  while (read_serial(serial_ind) != -1) { /* nada */ } // Clear out the RX buffer. Why don't use flush here ?
  flush_and_request_resend(serial_ind);
  serial_state[serial_ind.index].count = 0;
}

FORCE_INLINE bool is_M29(const char * const cmd) {  // matches "M29" & "M29 ", but not "M290", etc
  const char * const m29 = strstr_P(cmd, PSTR("M29"));