threads / discuss / 36524

git-svn Rewrites Some Commits, but not All

Subject: git-svn Rewrites Some Commits, but not All

## tl;dr

4 messages between Apr 28, 2014 and May 1, 2014.

replies: 3people: 3as markdown or json

Aaron Laws· Apr 28, 2014, 19:26 UTC · lore

Hello.

I've been using git-svn for some time now, and I'm very happy with it. There is one thing that I'm wondering about, however.

The way I understand it, when `git svn dcommit` is run, new commits are created (A' is created from A adding SVN information), then the current branch is moved to point to A'. Why don't we move any other refs that were pointing to A over to A' ? What would be the point of continuing to point to A? I'm interested in looking into coding this change to git-svn, but I would like to hear some feedback first.

If you understand what I'm saying, feel free to stop now, otherwise, a more verbose explanation follows:

Consider the following workflow:

Create a local branch tracking a SVN branch (I'll call it "master") On that branch, git checkout -b topic; Do some work, and git commit; git checkout master; git merge topic; git log --oneline --decorate --graph topic master Note that topic and master point to the same commit (it was a fast-forward) git svn dcommit; git log --oneline --decorate --graph topic master

Now we see that topic and master now point to different commits. git svn rewrote the master commits to add information about where those commits went in SVN (their rev number, the url, etc.).

I'm proposing that both master and topic should now be pointing to A'. This would allow numerous things to happen automatically that are pleasing, for instance: git branch -d topic; should succeed rather than warn about unmerged changes.

Thanks for listening; I look forward to hearing your thoughts.

In Christ, Aaron Laws

Piotr Krukowiecki· Apr 29, 2014, 22:04 UTC · re: Aaron Laws · lore

Re: git-svn Rewrites Some Commits, but not All

On Mon, Apr 28, 2014 at 9:26 PM, Aaron Laws <dartme18@gmail.com> wrote:

Show 6 quoted lines

> The way I understand it, when `git svn dcommit` is run, new commits
> are created (A' is created from A adding SVN information), then the
> current branch is moved to point to A'. Why don't we move any other
> refs that were pointing to A over to A' ? What would be the point of
> continuing to point to A? I'm interested in looking into coding this
> change to git-svn, but I would like to hear some feedback first.

Hi,

I think A' might not always be simply (A + SVN info). I think you can dcommit when you're not up to date. So A' will have a different parent than A (will be automatically rebased on top of current branch tip). Other refs pointing to A might be used as bookmarks, and moving them from A to A' would be a significant change.

-- 
Piotr Krukowiecki

Eric Wong· Apr 30, 2014, 06:59 UTC · re: Piotr Krukowiecki · lore

Re: git-svn Rewrites Some Commits, but not All

Piotr Krukowiecki <piotr.krukowiecki@gmail.com> wrote:

Show 13 quoted lines

> On Mon, Apr 28, 2014 at 9:26 PM, Aaron Laws <dartme18@gmail.com> wrote:
> > The way I understand it, when `git svn dcommit` is run, new commits
> > are created (A' is created from A adding SVN information), then the
> > current branch is moved to point to A'. Why don't we move any other
> > refs that were pointing to A over to A' ? What would be the point of
> > continuing to point to A? I'm interested in looking into coding this
> > change to git-svn, but I would like to hear some feedback first.
> 
> I think A' might not always be simply (A + SVN info). I think you can
> dcommit when you're not up to date.  So A' will have a different
> parent than A (will be automatically rebased on top of current branch
> tip). Other refs pointing to A might be used as bookmarks, and moving
> them from A to A' would be a significant change.

Right, I would not want "git rebase" (what dcommit uses internally) to scan all the branches in my repository and try to update them behind my back. It's far too surprising and potentially dangerous.

Aaron Laws· May 1, 2014, 12:52 UTC · re: Piotr Krukowiecki · lore

Re: git-svn Rewrites Some Commits, but not All

Ah, I missed that dcommit entails a rebase. I thought it just complained if one needed to take place, so I always do a rebase "manually" before dcommit. I agree, and would not want my other refs moved around if the change is that drastic.

The workaround is not so bad anyway: git reset on the left-behind refs. Thanks for the replies!

In Christ, Aaron Laws

On Tue, Apr 29, 2014 at 6:04 PM, Piotr Krukowiecki <piotr.krukowiecki@gmail.com> wrote:

Show 18 quoted lines

> On Mon, Apr 28, 2014 at 9:26 PM, Aaron Laws <dartme18@gmail.com> wrote:
>> The way I understand it, when `git svn dcommit` is run, new commits
>> are created (A' is created from A adding SVN information), then the
>> current branch is moved to point to A'. Why don't we move any other
>> refs that were pointing to A over to A' ? What would be the point of
>> continuing to point to A? I'm interested in looking into coding this
>> change to git-svn, but I would like to hear some feedback first.
>
> Hi,
>
> I think A' might not always be simply (A + SVN info). I think you can
> dcommit when you're not up to date.  So A' will have a different
> parent than A (will be automatically rebased on top of current branch
> tip). Other refs pointing to A might be used as bookmarks, and moving
> them from A to A' would be a significant change.
>
> --
> Piotr Krukowiecki