From: Steven Grimm <koreth@midwinter.com>
To: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Cc: git@vger.kernel.org
Subject: Re: [RFC] Replace rebase with filtering
Date: Tue, 16 Jan 2007 11:43:35 -0800 [thread overview]
Message-ID: <45AD2AE7.2010908@midwinter.com> (raw)
In-Reply-To: <45AD2568.4040408@midwinter.com>
Steven Grimm wrote:
> Johannes Schindelin wrote:
>> I had the impression that the use of "--ignore-if-in-upstream" in
>> git-rebase avoids exactly this case: re-applying changes which are
>> already in upstream.
> Where's that option documented? The manpage makes no mention of it at
> all.
Ah, okay, poking around in the git-rebase source, I see you mean that
git-format-patch is called with that option. Gotcha. The problem is that
after a rebase, the revisions in question *aren't* in the upstream.
Here's my understanding of why. Say I have this in my integration
repository:
a---b---c---d (master)
\
e---f---g (integration)
Now, I rebase the integration branch onto master:
a---b---c---d
\
e'---f'---g'
The problem is that, since e' contains all the changes in e *and* in
b/c/d, it does not have the same SHA1 as the original e revision, nor in
fact the same hash as any of the revisions in the pre-rebase tree. And
after rebase succeeds, it wipes the original e, f, and g from the
history of the integration branch.
When a clone fetches e', f', and g' from this repo and tries to rebase
onto the integration branch, git-format-patch will think b, c, and d are
new (correct) but also that e', f', and g' are new. Since they have
previously unknown hashes and there's no record of the original e, f,
and g or their relation to the new revisions -- at least, no record that
gets pulled down to the clone when it fetches -- there's no way for
git-format-patch to know that it has already applied those changes.
As always, correct me if I'm wrong -- that's my understanding of the
problem with rebasing in a parent repository.
-Steve
next prev parent reply other threads:[~2007-01-16 19:43 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-01-16 2:41 [RFC] Replace rebase with filtering Steven Grimm
2007-01-16 11:18 ` Johannes Schindelin
2007-01-16 19:20 ` Steven Grimm
2007-01-16 19:43 ` Steven Grimm [this message]
2007-01-16 20:35 ` Johannes Schindelin
2007-01-16 20:40 ` Steven Grimm
2007-01-16 21:14 ` Jakub Narebski
2007-01-16 21:22 ` Shawn O. Pearce
2007-01-16 21:23 ` Johannes Schindelin
2007-01-16 21:20 ` Johannes Schindelin
2007-01-16 21:49 ` Jakub Narebski
2007-01-16 22:31 ` Brian Gernhardt
2007-01-16 22:51 ` Johannes Schindelin
2007-01-16 22:53 ` Junio C Hamano
2007-01-16 22:57 ` Johannes Schindelin
2007-01-17 22:21 ` Steven Grimm
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=45AD2AE7.2010908@midwinter.com \
--to=koreth@midwinter.com \
--cc=Johannes.Schindelin@gmx.de \
--cc=git@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).