I’ve just learned how to manage shared group directories with the linux access control lists. The package in debian is called acl and we have two command line tools: setfacl, getfacl. To give read/write access to the group web in public_html, this is quite simple.
sudo setfacl -R -d -m group:web:rw- public_html
ah… and it works with nfs as well. This should also solve various problems with svn.
chgrp cvs db db/transactions db/write-lock db/revs db/revprops hooks locks
chmod 2770 db db/transactions db/revs db/revprops
chmod 660 db/write-lock
chmod 750 hooks
chmod 770 locks
setfacl -m "group:svn-ro:r-x" db db/revs db/revprops locks