So I am going to fly from US (city A) to a city (city B) in China via Shanghai. The flight from Shanghai to City B is a code share flight operated by a Chinese airline. Now, I want to spend couple days in Shanghai for fun, and then travel to city B by myself.

Now, if I buy a round trip ticket like this, A-shanghai-B-shanghai-A, and forfeit the shanghai-B leg, will that cause trouble for me to fly back from B to A via Shanghai?

Or should I break it up and book two one-way tickets instead?