threads / discuss / 8533

Is this an acceptable workflow in git-svn, or a user error?

Subject: Is this an acceptable workflow in git-svn, or a user error?

## tl;dr

4 messages between Jun 9, 2007 and Jun 10, 2007.

replies: 3people: 3as markdown or json

Junio C Hamano· Jun 9, 2007, 19:10 UTC · lore

Suppose you are interacting with svn://some.where/ and you want to have a public git://my.svn/mirror.git maintained with your effort for others to consume. I am wondering if the following workflow, especially the push part, is kosher.

----------------------------------------------------------------
0. Priming the process

$ (mkdir mirror.git && cd mirror.git && git init)

$ mkdir private.git && cd private.git && git init $ git svn init svn://some.where/ $ git push ../mirror.git/ refs/heads/master:refs/heads/master

After this step, mirror.git would be in-sync with the SVN; we haven't done any of our own development yet.

1. Hack away

$ edit/git-add/etc. $ git commit

2. Publish the result

git push ../mirror.git/

3. Re-sync with SVN

$ git svn dcommit ----------------------------------------------------------------

I suspect that the above sequence is a user error, in that re-syncing with SVN using git-svn (either dcommit or rebase) would need to redo the commits to embed SVN metadata, but the public mirror now has commits made with git without such rewriting. In other words, I suspect that "git push" should never be done if you made changes on the git side since you sync'ed with the SVN.

The reason I am asking is that somebody on #git got in a very confusing situation. After the Re-sync, "git push" to the mirror would refuse because it is not a fast forward. "git fetch" from the mirror reveals that what after 3. is done, we see two identically-looking commits, one that was pushed (before re-sync with SVN) and the other (replaced because of re-sync) are different.

If that is the case, then I presume that the correct workflow would be:

1. Hack away
2. Re-sync with SVN
3. Publish the result; do not do anything between 2. and 3.

Is my understanding correct?

Eric Wong· Jun 9, 2007, 19:38 UTC · re: Junio C Hamano · lore

Re: Is this an acceptable workflow in git-svn, or a user error?

Junio C Hamano <gitster@pobox.com> wrote:

Show 38 quoted lines

> Suppose you are interacting with svn://some.where/ and you want
> to have a public git://my.svn/mirror.git maintained with your
> effort for others to consume.  I am wondering if the following
> workflow, especially the push part, is kosher.
> 
> ----------------------------------------------------------------
> 0. Priming the process
> 
> $ (mkdir mirror.git && cd mirror.git && git init)
> 
> $ mkdir private.git && cd private.git && git init
> $ git svn init svn://some.where/
> $ git push ../mirror.git/ refs/heads/master:refs/heads/master
> 
> After this step, mirror.git would be in-sync with the SVN; we
> haven't done any of our own development yet.
> 
> 1. Hack away
> 
> $ edit/git-add/etc.
> $ git commit
> 
> 2. Publish the result
> 
> git push ../mirror.git/
> 
> 3. Re-sync with SVN
> 
> $ git svn dcommit
> ----------------------------------------------------------------
> 
> I suspect that the above sequence is a user error, in that
> re-syncing with SVN using git-svn (either dcommit or rebase)
> would need to redo the commits to embed SVN metadata, but the
> public mirror now has commits made with git without such
> rewriting.  In other words, I suspect that "git push" should
> never be done if you made changes on the git side since you
> sync'ed with the SVN.

Yes. This is an unfortunate sore point for git-svn users unfamiliar with what rebase does (inside dcommit). Users using the the old 'set-tree' workflow are immune to this, but they have their own set of complications...

Using "git push --force" would work after dcommit, however that makes extra work for people tracking the git mirror

Show 16 quoted lines

> The reason I am asking is that somebody on #git got in a very
> confusing situation.  After the Re-sync, "git push" to the
> mirror would refuse because it is not a fast forward.  "git
> fetch" from the mirror reveals that what after 3. is done, we
> see two identically-looking commits, one that was pushed (before
> re-sync with SVN) and the other (replaced because of re-sync)
> are different.
> 
> If that is the case, then I presume that the correct workflow
> would be:
> 
> 1. Hack away
> 2. Re-sync with SVN
> 3. Publish the result; do not do anything between 2. and 3.
> 
> Is my understanding correct?

Yes.  Since dcommit uses rebase, it'll rewrite history.

The "git svn dcommit" workflow is analogous to me making commits and mailing patches to you to apply to the mainline git.git. When you apply them to git.git, they'll be different than the commits I've made even though they're only metadata changes.

-- 
Eric Wong

Sam Vilain· Jun 10, 2007, 07:44 UTC · re: Eric Wong · lore

Re: Is this an acceptable workflow in git-svn, or a user error?

Eric Wong wrote:

Show 5 quoted lines

>> Is my understanding correct?
>>     
>
> Yes.  Since dcommit uses rebase, it'll rewrite history.
>

Maybe these new lightweight annotations could be a way around that?

Sam.

Sam Vilain· Jun 10, 2007, 07:49 UTC · re: Sam Vilain · lore

Re: Is this an acceptable workflow in git-svn, or a user error?

Sam Vilain wrote:

Show 8 quoted lines

> Eric Wong wrote:
>   
>>> Is my understanding correct?
>>>       
>> Yes.  Since dcommit uses rebase, it'll rewrite history.  
>>     
> Maybe these new lightweight annotations could be a way around that?
>

Actually I don't think that will work either unless you start encapsulating extra git information (author/committer email/timestamps) in the svn commit somewhere, so that someone else fetching the commits from svn directly will end up with the same git commitid. And then there's still the issue of merges.

Sam.