svn moved permanently error in an Apache virtual host

Question

I am trying to serve a Subversion repository via Apache. I am using a separate hostname for the svn repository. Here is the Apache configuration:

<VirtualHost *:443>
  ServerName svn.mydomain.com
  DocumentRoot /var/svn

  SSLEngine on
  SSLCertificateFile    /etc/ssl/certs/svn_mydomain_com.pem
  SSLCertificateKeyFile /etc/ssl/private/svn_mydomain_com.key

  <Location /myrepo>
    DAV svn
    SVNPath /var/svn/myrepo
    AuthType Basic
    AuthName "Subversion Repository"
    AuthUserFile /var/www-s/trac/trac.passwd
    Require valid-user
</VirtualHost>

The directory /var/svn has a single subversion repository myrepo and no other subdirectories.

When I do a checkout of https://username@svn.mydomain.com/myrepo I get

svn: Repository moved permanently to 'https://svn.mydomain.com/myrepo/'; please relocate

I have looked at Subversion error: Repository moved permanently to please relocate but I cannot see what I am doing wrong.

(Note that I am using name-based virtual hosting on port 443 using SNI with my Apache 2.2 setup.)