Non-XML characters in svn:author values break PROPFIND:
svnadmin create repo
ln -s /bin/true repo/hooks/pre-revprop-change
svn propset --revprop -r0 svn:author `printf "xx\byy"`
http://localhost:8888/obj/repo
svn propget --revprop -r0 svn:author http://localhost:8888/obj/repo
svn: E130003: The PROPFIND response contains invalid XML (207 Multi-Status)
For the propset the client base64 encodes svn:author and mod_dav_svn decodes.
For the propget there is no base64 and the XML is invalid.
Checkout and update are possible, mod_dav_svn base64 encodes svn:author and the
client decodes.