Re: Rebasing cascading topic trees

[Norbert Kiesel <nkiesel@gmail.com>]

More things I learned!

So there are (at least) 2 possible approaches: using history, or using
local tracking branches.  The latter looks actually nicer to me, with
the exception that if asks for a `git pull`.  Using `git pull
--rebase` actually also ends up with the same tree, but I like the
rebase better.

The following 2 scripts show the 2 approaches.  Only difference is in
the creation of topic/b and the last rebase command.

# History
mkdir topic; cd topic
git init
date > a; git add a; git commit -m a
date > b; git add b; git commit -m b
git branch -b topic/a
git checkout -b topic1
date > c; git add c; git commit -m c
date > d; git add d; git commit -m d
git checkout -b topic2
date > e; git add e; git commit -m e
date > f; git add f; git commit -m f
git checkout master
date > g; git add g; git commit -m g
echo "before rebase"; git log --oneline --graph --all
git rebase master topic1
echo "after rebase of topic1"; git log --oneline --graph --all
git rebase --onto=topic1 topic1@{1} topic2
echo "after rebase of topic2"; git log --oneline --graph --all

# Tracking
mkdir topic; cd topic
git init
date > a; git add a; git commit -m a
date > b; git add b; git commit -m b
git branch -b topic/a
git checkout -b topic1
date > c; git add c; git commit -m c
date > d; git add d; git commit -m d
git checkout --track topic1 -b topic2
date > e; git add e; git commit -m e
date > f; git add f; git commit -m f
git checkout master
date > g; git add g; git commit -m g
echo "before rebase"; git log --oneline --graph --all
git rebase master topic1
echo "after rebase of topic1"; git log --oneline --graph --all
git rebase --onto=topic1 master topic2
echo "after rebase of topic2"; git log --oneline --graph --all

On Wed, Nov 16, 2016 at 5:45 PM, Jeff King <peff@peff.net> wrote:
> On Wed, Nov 16, 2016 at 04:12:20PM -0800, Norbert Kiesel wrote:
>
>> Yes, `git rebase --onto topic1 topic1@{1} topic2` is the answer!
>
> See also the `--fork-point` option, which (I think) should do this for
> you (and is the default if "topic1" is the configured upstream for
> topic2 and you just run "git rebase").
>
> -Peff