Here's another reference that has some .htaccess suggestions

• Joseph Scott

See

• Updating WordPress with Subversion
• Scripts to use SVN
• Installing WordPress With Clean Subversion Repositories

My steps for a fairly simple case with the file structure

• <docroot>/wp-content -- has themes and plugins; assumes there's a separate, local, subversion repository for the changes to themes and any plugins that have had local changes
• <docroot>/wp -- has core files
• <docroot>/wp-config.php -- has defines to support above structure
• <docroot>/index.php -- required for WordPress core to be installed in a subdirectory, see Giving WordPress Its Own Directory
• <docroot>/uploads -- for files uploaded through WordPress with path set in the application. A separate backup scheme may be appropriate for these files (may or may not use subversion).

Steps to upgrade, say Vxx (e.g. 2.6.5) to Vyy (e.g. 2.6.7)

1. Backup everything
   1. Backup the database
   2. Deactivate all the plugins
   3. Ensure the subversion repository for the wp-content directory and other site customizations is up to date.
   4. Use an appropriate backup for the uploads directory (while an upgrade is unlikely to affect these files, it may be the trigger to make sure there's a backup)
   5. In the file system
      • $ cd <docroot>
      • $ mv wp wp-Vxx
2. Install new files
   • $ mkdir wp
   • $ cd wp
   • $ svn sw http://svn.automattic.com/wordpress/tags/Vyy .
   • $ mv wp-content wp-content-Vyy
3. Login and continue with the standard upgrade as performed any other way.

To revert to the previous version, restore the database and put the old file system back in place.