What happens when two different people fixed and send the same patch at the same time?
Suppose that both works completely and both send at the send time, still coding varies from a programmer to another.
- The more optimized code will applied.
- Programmer reputation also helps
- previous works done the programmars
- How much each code will be dynamic to later changes
you can find many criteria that affect the chose.
Thanks to @ThomasW comment, if it happens that two patches are identical and other criteria the same (which is generally considered rare, I think):
If that is the case then there's no rules for which to use or not, and you can credit both contributors for the same patch.