When deleting a file, git-diff outputs "+++ /dev/null" and "deleted file mode", neither of which are understood by SVN. Rather, SVN expects the new filename to be the same as the deleted one. This is important when doing file renames or deletions when using git-svn.

Successfully used this code to post a review for a basic set of file renames (~10 files). Posted to RB 1.6 and it seemed to be happy.