(defun vc-svn-modify-change-comment (files rev comment)
"Modify the change comments for a specified REV.
You must have ssh access to the repository host, and the directory Emacs
-uses locally for temp files must also be writeable by you on that host.
+uses locally for temp files must also be writable by you on that host.
This is only supported if the repository access method is either file://
or svn+ssh://."
(let (tempfile host remotefile directory fileurl-p)