For safetly running I recomend add 2 universal Si-diode, e.g. 1N4007.
1. add diode to output - anode to GNG and cathode to +V
2. add diode like bridge over LM317 - anode to Vout and cathode to Vin
If You want using this power supply with minimum outgoing current (e.g. LCD-panel) You must add...