Adapt log example to use OldestFirst sorting for -r/--reverse option

[jakewilliami]

How can I adapt the log example to reverse the order of the rev_walk by commit time without collecting the iterator, reversing it, and turning it back into an iterator?

I tried this:

// ...
use gix::{
    // ...
    traverse::commit::simple::CommitTimeOrder,
};
// ...
    let sorting = if args.breadth_first {
        Sorting::BreadthFirst
    } else {
        Sorting::ByCommitTime(if !args.reverse {
            CommitTimeOrder::NewestFirst
        } else {
            CommitTimeOrder::OldestFirst
        })
    };
// ...

Rather than doing it in a vector:

    if args.reverse {
        let mut results: Vec<_> = log_iter.collect();
        results.reverse();
        log_iter = Box::new(results.into_iter());
    }

But this produces incorrect results.

[Byron]

There is no way to reverse the order of commits shown other than collecting them first.

CommitTimeOrder::OldestFirst has a different effect as it sorts only the commits at each 'junction' of the graph, which can be used to reach the beginning of the graph much faster. But that's already it.