how to fix git-svn if the svn repo moves

I’m using git-svn at the moment, as the owner of a project I’m working on is using subversion. The svn server has just moved to a new domain name. Unfortunately this broke git-svn as I couldn’t rebase (got an error like this:
“RA layer request failed: PROPFIND request failed on ‘/svn’: PROPFIND of ‘/svn’: 200 OK (http://$OLD_DNS_NAME) at /usr/local/bin/git-svn line 1839” )

Just editing .git/config and changing the url for the svn repo doesn’t work as rebasing will produce the following error: Unable to determine upstream SVN information from working tree history.

The solution to this problem is as follows:

• edit the svn-remote url URL in .git/config to point to the new domain name
• run git svn fetch
• change svn-remote url back to the original url
• run git svn rebase -l to do a local rebase (with the changes that came in with the last fetch operation)
• change svn-remote url back to the new url
• git svn rebase should now work again!