You can press the Return key? :)

    const uint64_t *p=bsearch(&ref->u,
                              df->file_offsets,
                              df->num_file_offsets,
                              sizeof df->file_offsets[0],
                              &CompareU64s);

That's from emacs. It's a bit hit or miss whether editors do something nice like the above, or just indent the arguments by one stop, but other options seem to be fairly rare.

I generally have one function call per line for ease of debugging. Nothing worse than having to do a fiddly step in/step out dance when you're trying to think about what's going on. But it's also good for keeping on top of line lengths too.

Eh, seems fine, just seems odd to be forced to do that for a three-argument function.