Do I need a transfer visa? I'm flying to Shanghai with Chinese Eastern from Seoul and this flight isn't connected to the first one.

Some say yes, others no, please help. I don't really feel like getting to the airport only so they tell me sorry we cannot let you board the plane. I'm Croatian and I have a ticket Shanghai-Moscow-Split. I'm flying to Shanghai with Chinese Eastern from Seoul and this flight isn't connected to the first one. I'm landing in Shanghai around 7PM and leaving for Moscow at 2.30 AM. So do I need it or what? Please say I don't:-) Thanx