Okay, this has been bugging me for a while. A Hong Kong film about a ‘renegade’ Hong Kong cop, on the trail of either a drug lord or a gang lord. He’s about to catch him when the bad guy goes over the border to China. This requires the cop to go over and abide by the rules of the mainland. He is partnered with a Chinese cop who does things ‘by the book’. All I remember is a scene of the cop sleeping over night in the station, on one of those uncomfortable looking benches, and it was made in the 90’s.
Sounds like Supercop with Jackie Chan. The original HK title is Police Story 3.
https://www.youtube.com/watch?v=KsBcuVOkEsg