Re: Walking commits from the first

[Pavan Kumar Sunkara <pavan.sss1991@gmail.com>]

> In most repositories, you can do this:
>
>  git checkout `git rev-list --reverse HEAD | head -n 1`
>

Thanks for the command

> It is not as simple as that, for two reasons.
>
> For walking backwards, you can take multiple paths from merge commits
> (which have multiple parents). So there may actually be several "first
> commits" if unrelated lines of development were merged together. For
> example, in git.git:
>
>  $ git log --format='%h %p' |
>    grep ' $'
>  16d6b8a
>  cb07fc2
>  161332a
>  1db95b0
>  2744b23
>  e83c516
>
> There are six root commits. You can see what they are by piping the
> above into "tr -d ' ' | git log --no-walk --stdin".
>
> For your "--next" suggestion, it is even worse. There may be an infinite
> number of commits that point to a given commit as the parent. So there
> is no such thing as "what came next from X". You can only ask
> "leading up to some commit Y which is a descendant of X, what was the
> commit that came after X". But while there are a finite number of
> answers, there is not necessarily just one. If two branches diverged at
> X and then remerged before Y, they are both equally "next".
>
> -Peff
>

My bad. I never thought of branch merging while writing this
So, if i want to get the second commit, Is this enough or will i get
the problem of branch diverging, if there is a branch diverging from
there.

git checkout `git rev-list --reverse HEAD | head -n 2`

Even though we have the problem branches to travel reversely, we can
do it in another way. As, we have the timestamp for every commit, then
it will be easy to implement --next. Take the next commit in timeline
and checkout. Even though it's completely different branch, no problem
as long as we are going in order.

Also we can have git checkout --next --same-branch to checkout the
next commit in timeline of the same branch.