How can I track a single branch on subversion with git

I'd like to track a remote bran开发者_运维问答ch on SVN from within Git. I can see the basics of how to do this with the git-svn command, I was hoping to do something like the following:

Git branch | SVN branch
-----------------------
master     | Trunk
feature1   | <not mapped>
feature2   | <not mapped>

so that once I merge into git/master, and then do dcommit, Trunk would be updated with only changes between the last svn commit and the git/HEAD.

Is this possible? how would I do it?

The git svn documentation describes working with Subversion's trunk, but with a dirty master:

# Clone a repo (like git clone):
    git svn clone http://svn.example.com/project/trunk
# Enter the newly cloned directory:
    cd trunk
# You should be on master branch, double-check with 'git branch'
    git branch
# Do some work and commit locally to git:
    git commit ...
# Something is committed to SVN, rebase your local changes against the
# latest changes in SVN:
    git svn rebase
# Now commit your changes (that were committed previously using git) to SVN,
# as well as automatically updating your working HEAD:
    git svn dcommit
# Append svn:ignore settings to the default git exclude file:
    git svn show-ignore >> .git/info/exclude

To do your work on feature branches instead of master

git checkout -b feature1
hack ...
git add ...
git commit ...

When you're ready to get your work back into Subversion, be sure to keep your history linear:

git checkout master
git svn rebase
git rebase master feature1
git checkout master
git merge feature1

Ship it!

git svn dcommit