A Malindo Air Boeing 737-800, registration 9M-LNT performing flight OD-163 from Dhaka (Bangladesh) to Kuala Lumpur (Malaysia), was enroute at FL310 about 40 minutes into the flight when the crew decided to return to Dhaka reporting a cracked windshield. The aircraft landed safely back in Dhaka about 90 minutes after departure. The flight was cancelled. The airline reported the aircraft returned due to a cracked windshield. The passengers were rebooked onto other flights.