I've recently been promoted into managing one of our most important projects. Most of the code in this project has been written by a partner of ours, not by ourselves.
The code in question is of very questionable quality. Code duplication, global variables, 6-page long functions, hungarian notation, you name it. And it's in C.
I want to do something about this problem, but I have very little leverage on our partner, especially since the code, for all its problems, "just works, doesn't it?".
To make things worse, we're now nearing the end of this project and must ship soon. Our partner has committed a certain number of person-hours to this project and will not put in more hours.
I would very much appreciate any advice or pointers you could give me on how to deal with this situation.