In order to allow multiple users to write to a subversion repository over svn+ssh, every user needs to have read and write access to the files in the repository. This can be achieved as follows:
chmod g+s repository)The last point can be achieved by a wrapper script for svnserve:
#!/bin/sh
# wrapper script for svnserve
umask 0002
exec /usr/bin/svnserve "$@"
This script has to be installed somewhere on the PATH, e.g. in /usr/local/bin/svnserve, with execute permissions.