If the code in the main repository has been altered, other users' working copies will of course not automatically be updated. In general, it is only necessary to execute the following steps in order to completely update your working copy of the code:
This will examine each entry in your working copy and compare it to the most recent version in the main repository. When the file in the main repository is more recent, your version of the code will be updated. If you have made changes to your version, but the version in the main repository has not changed, the altered code will be identified to you with an ``M''. If you have made changes to your version of the code, and one or more newer versions have been updated in the main repository, SVN will examine the two versions and attempt to merge them - this process often reveals conflicts, however, and is sometimes unsuccessful. You will be notified of any conflicts that arise (labelled with a ``C'') and you must resolve them manually.
If new directories have been added to the repository, the update above will automatically add them to your working copy. However, you may need to re-run autoconf and configure ( $objdir/config.status -recheck is a convenient command) to be able to build the new code.