Migrating SVN to Git, and preserve merge information

Hi,

I currently have two SVN repositories I'm looking to convert to Git. While the process itself isn't all that hard (following this guide[1]), I'm looking to do a bit more than just convert raw commits.

The repositories basically have two main branches at a time, for example:

* trunk
* current version, for example 3.5

Our SVN workflow consisted of working on trunk, and then manually merging single commits from trunk to the other branch. We quite consistently mentioned the merged commits in the SVN commit message, and I'm looking to use this information to generate a more accurate tree in Git. The commit messages are for example:

trunk rev 100: Fixed important bug branch rev 101: Merged r100 from trunk

Or more elaborate:

branch rev 200: Merged r100,r101,r.... from trunk

In these examples, tools like gitk or git log should show a line from rev 100 to rev 101 in the first example, and lines from r100, r101,rn to rev 200 in example two.

I have tried to create a custom grafts file to create the parent-child relations above, and basically finds all merge commits and converts them into graft lines like so:

<merge commit sha hash> <original git parent sha hash> <sha hash of merged rev 1> ... <sha hash of merged rev n>

This all works to a certain extent, but the problem arises when trying to view older history in these repositories. If I use the grafts file, and do `gitk --all`, gitk freezes. Gitg doesn't show commits before a certain point. tig and `git log --graph` all show a huge amount of parentless commits near the bottom. All of this leads me to the conclusion that something is wrong with the method of using grafts, rather than problems in the individual tools.

Can someone find something obvious that I'm missing in the above approach? Or alternatively suggest another more appropriate method of achieving the same results in Git?

Kind regards,

Nick Douma

[1]: http://john.albin.net/git/convert-subversion-to-git