git-svn messing up merge commits on dcommit

Hi Eric,

I have two "test cases" here (attached), which I actually wrote months ago, but forgot to sent, as I wanted to clean them up/turn them into something suitable for the test suite, but honestly, I'll probably never get around to do that, so here they are, as they are. They show git-svn messing up merge commits when dcommitting a branch that is not up-to-date WRT the svn repo.

The basic history for both cases (before dcommit) is:

        C---D (master)
       /   /
      /---E (side)
     /
A---B (trunk)
     \
      X (revision in SVN, not yet fetched)

So the dcommit (which would send C and D to the svn repo) needs to "rebase" C and D.

In the first test case, this rebasing causes conflicts, and leads to a linearized history:

      E (side)
     /
A---B---X---C' (trunk)
             \
              D (master)

The merge is broken apart. This is probably expected, but I thought I'd tell anyway.

The second test case is a bit more interesting, there are no conflicts between the local commits to be dcommitted and the new commit X in the svn repo. In this case, git-svn manages to dcommit the merge commit just fine, keeping the history correct, but it messes the merge commit's commit message up. So the history becomes:

A---B---X---C'--D' (trunk) (master)
     \         /
      --------E (side)

But D' has the same commit message as C/C', not the one from D.

I hope that makes any sense to you (or you can figure it out from the testing scripts).

Björn

#!/bin/sh mkdir git-svn-test cd git-svn-test

SVN="file://$PWD/svnrepo" svnadmin create svnrepo svn co "$SVN" co cd co svn mkdir trunk tags branches svn ci -m init

echo 123 > trunk/foo svn add trunk/foo svn ci -m "SVN 1"

cd ..

git svn clone -s "$SVN" git

cd co echo 456 >> trunk/foo svn ci -m "SVN 2" cd ..

cd git git checkout -b side echo 123 >> foo git add foo git commit -m "On side" git checkout master echo 123 > foo3 git add foo3 git commit -m "On master" git merge --no-ff side gitk --all& git svn dcommit echo resolved > foo git add -u git rebase --continue gitk --all

#!/bin/sh mkdir git-svn-test cd git-svn-test

SVN="file://$PWD/svnrepo" svnadmin create svnrepo svn co "$SVN" co cd co svn mkdir trunk tags branches svn ci -m init

echo 123 > trunk/foo svn add trunk/foo svn ci -m "SVN 1"

cd ..

git svn clone -s "$SVN" git

cd co echo 456 >> trunk/foo svn ci -m "SVN 2" cd ..

cd git git checkout -b side echo 123 >> foo2 git add foo2 git commit -m "On side" git checkout master echo 123 > foo3 git add foo3 git commit -m "On master" git merge --no-ff side gitk --all& git svn dcommit gitk --all&

Björn Steinbrink <B.Steinbrink@gmx.de> wrote:

As noted in the CAVEATS section of the manpage, pull/merge isn't recommended with dcommit because it generates non-linear history.

Keep in mind this was written before SVN got merge tracking support, but I haven't been particularly motivated to revisit the topic since then...

Thanks for posting these, though. They do seem to be good test cases for developing on and hopefully somebody with more interest in this topic can pick up where we leave off.

On a side note, I have been meaning to refactor git svn and break it apart into separate Perl modules for easier hacking for the longest time now...