Re: [PATCH RFC] rebase: add --revisions flag

From: Björn Steinbrink <b.steinbrink@gmx.de>
Date: Dec 8, 2009, 16:37 UTC
Message-ID: <20091208163737.GA2005@atjola.homenet>
In-Reply-To: <20091208161406.GB32045@redhat.com>

On 2009.12.08 18:14:07 +0200, Michael S. Tsirkin wrote:

Show 20 quoted lines

> On Tue, Dec 08, 2009 at 05:08:22PM +0100, Björn Steinbrink wrote:
> > On 2009.12.08 16:47:42 +0200, Michael S. Tsirkin wrote:
> > > Add --revisions flag to rebase, so that it can be used
> > > to apply an arbitrary range of commits on top
> > > of a current branch.
> > > 
> > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> > > ---
> > > 
> > > I've been wishing for this functionality for a while now,
> > > so here goes. This isn't yet properly documented and I didn't
> > > write a test, but the patch seems to work fine for me.
> > > Any early flames/feedback?
> > 
> > This pretty much reverses what rebase normally does. Instead of "rebase
> > this onto that" it's "'rebase' that onto this". And instead of updating
> > the branch head that got rebased, the, uhm, "upstream" gets updated.
> 
> The last sentence is wrong I think - it is still the branch head that
> is updated.

But you don't rebase the branch head. Before the rebase, the branch head doesn't reference the commits that get rebased. For example:

git checkout bar git rebase --revisions foo bar

You "rebase" the commits in foo's history, but you update bar.

WRT the result, the above command should be equivalent to: git checkout bar git reset --hard foo git rebase --root --onto ORIG_HEAD;

And here, the commits currently reachable through "bar" are rebased, and "bar" also gets updated.

Björn