"git svn fetch" on a branch is broken after "git svn reset"

The documentation for git svn claims that this should work:

    git svn reset -r2 -p
    git svn fetch

But when I tried it (using an SVN tree that has recent commits only in a branch, not the trunk), it didn't work correctly. "fetch" grabbed just the latest version from SVN, and not all revs from <revnum> to the head! Note that it matters that this is in an SVN branch-- if I repeat the test using revs in the trunk, everything works as expected.

Specifically, what I did was this:

    git co -b testing refs/remotes/test-branch
    git svn fetch

    git svn reset -r 850
    # does correctly rewind to rev 850, undoing commits in test-branch

    git svn fetch
    # oops, only fetches the *head* revision (rev 856) from SVN!
    # In refs/remotes/test-branch, SVN rev 850 is now followed by 856!

I then tried this again, but between reset and fetching I manually edited .git/svn/.metadata and moved back the *-maxRev versions to 850; after doing this, the fetch does the right thing. I tried examining the logic in git-svn.perl to figure out why this happens and why it would be affecting a branch but not the trunk, but I didn't get very far.

I can reproduce the problem on Linux (git version 1.7.2.1) and Windows (Git for Windows version 1.7.3.2.msysgit.0.4.ga4f3f or Cygwin git 1.7.2.3).

Thoughts?

--bert