My passport expires in Sept 2014. I have applied and received a chinese visa (Q2 visiting relatives), which expires in Mar 2014.

But something has come up that I might need to renew my passport before arriving in China.

Has anyone had any experience renewing their passport AFTER obtaining a valid visa but BEFORE using it to enter China?

I will have my old passport (passport will have been cancelled, but has valid visa) and new passport (with no visa on it)? Will border patrol give me hassle about it

Edit: Both old and new passport are Canadian. FWIW