Tag: svn

Earlier this week, I needed to work on a feature branch on the company’s subversion repository. (The one I did a git copy of a month ago).

Imagine my surprise when I couldn’t see the feature branch with git branch -r. The command shows all the branches and tags in a git repository. The branch was created after my initial cloning, and was not pulled down with subsequent git svn rebase.

It turned out to get subversion branches created after cloning, you need to do a fetch instead.

git svn fetch
git branch -r

Reading the git-svn man page more carefully, rebase only fetches revisions from the SVN parent of the current HEAD. In comparison, fetch fetches unfetched revisions from the tracked Subversion remote.

I recently found myself working on a very large subversion (svn) repository. The repository (possibly) contains the company’s entire code base, spanning nearly 90,000 revisions. Even within the module I’m working on, there are over 300 branches.

Being a git convert, the first thought that occurred to me was to try git-svn, instead of moving back to svn. I love the ability to create multiple local feature branches. (I also prefer the way git merging works. But git-svn is restricted to the svn merge model).

For projects with many branches, it is recommended you clone one directory only. Otherwise, the resulting git repository will be many times larger than the original trunk.

git svn clone http://svn.mycompany.com/projectx/iteration123

Partial Cloning

However, I wanted to clone the trunk and a selection of branches. There are the options –trunk, –tags, –branches for svn repositories with non-standard layouts. Git-svn will also skip checking out paths specified with the option –ignore-paths.

After some experimentation, I found it easier to create an empty git repository, manually edit .git/config, and then fetch. Instead of using the command line options to clone.

git svn init http://svn.mycompany.com/projectx

Edit .git/config

[svn-remote "svn"]
url = http://svn.mycompany.com/projectx
fetch = trunk:refs/remotes/trunk
branches = branches/{iteration123}:refs/remotes/branches/*

The branches entry must contain a wildcard, or git-svn will complain with an error message along the lines of ‘glob needed’. I used the curly braces to fetch the branch iteration123 only. Multiple branches can be specified comma separated, like {iteration123,iteration124}.

I also restricted the fetch to recent revisions, by using the -r option

git svn fetch -r 80000:HEAD

Workflow

After the initial cloning hurdle, I found git-svn very straightforward to use.

At the start of each day, I merged changes from svn by using

git svn rebase

I committed changes to my local git repository with

git commit (-a)

Git-svn pushes each local commit as a separate commit to the remote svn. However, I committed very often and I really didn’t fancy polluting the svn log with lots of ‘reverting’, ‘trying x approach’. Therefore, I squashed all my commits for a scrum task into one commit before pushing the changes back to svn trunk.

git rebase -i branches/iteration123
git svn dcommit