Re: Specifying N revisions after the initial commit

On Tue, Sep 22, 2015 at 2:40 PM, Konstantin Khomoutov
[off-list ref] wrote:

On Tue, 22 Sep 2015 14:32:19 -0400
Josh Boyer [off-list ref] wrote:

quoted

Please CC me as I'm not subscribed.

I was hoping someone could help me with the revision shorthand to get
the commit sha of a commit N commits after the initial commit.

What happens if right after the initial commit, there have been five
branches created -- with no common commits except for the initial one?

That's the core limitation of the data model Git uses (and arguably any
other DVCS system): all commits form a directed acyclic graph.
The "directed" in that construct means that child commits contain a
link to their parent commit (or commits) but not vice-versa.

Hm.  It has been so long since I've looked at the underlying model and
git has proven to be so flexible on such a variety of things that I
guess I forgot it was constructed through a DAG.  The --reverse
parameter to git-log and git-rev-parse had left me hopeful.

Hence, given any particular commit, you're able to trace all of its
ancestry, but the reverse is not possible.

That makes sense.  I suppose I will have to resort to parsing output
of git-rev-list or something.  Thanks for the reminder.

josh