Can I call LLVMFuzzerMutate multiple times for different subsets of data

[ktmf01]

I'd like to implement a custom mutator to improve fuzzing in the flac project.

In this case, the custom mutator would unpack a series of packets, mutate them, and then repack them to form a single stream. I'm unsure what the best way is to do this.

• Should I call LLVMFuzzerMutate for each packet separately?
• Should I call LLVMFuzzerMutate for one packet, with a packet chosen based on the seed? (For example, if the stream has 8 packets, take the (seed % 8)th packet and mutate it? This guess this only works properly if the seed is different for each mutation?
• Should I call LLVMFuzzerMutate once for all packets concatenated, and then split them based on the old split locations?

[nwellnhof]

In general, I wouldn't make multiple unrelated mutations at once, so I'd go with the second option. The seed will be different for each mutation.