git-rev-list --date-order ?

Junio,

Gitk has a -d option that tells it to reorder the commits in
decreasing order of their commit time, subject to the constraint that
parents come after all of their children.  Currently it uses
git-rev-list --header --topo-order --parents and then reorders the
commits internally.

How hard would it be to add a --date-order flag to git-rev-list to
make it order the commits in decreasing commit time order, subject to
the constraint that parents come after their children?

If we had that then I could remove another chunk of code from gitk and
make it a bit faster.

Thanks,
Paul.