In 2002, a group of researchers presented a paper on Cyclone, a safe dialect of C [1]. While (manually) porting code from C to Cyclone, they found safety bugs in the C code.
These kinds of manual or automated conversation from C to <safer language> therefore have potential not only for increasing adoption of safer languages but also for uncovering existing bugs.
[1] https://www.researchgate.net/profile/James-Cheney-2/publicat...