subversion

Piston is a utility that eases vendor branch management. This is similar to svn:externals, except you have a local copy of the files, which you can modify at will. As long as the changes are mergeable, you should have no problems.
Install Piston
First, you need to have Ruby installed (even though we aren't doing any programming in Ruby) in order to run Piston:

1. Shut down svnserve, Apache, and anything else that might be accessing the repository:
   
   svc -d /service/apache
2. Dump a backup of the repository using the currently installed Subversion:
   
   svnadmin dump /var/svn/repo_name > dumpfile.txt
3. Move the current repository to make room for a new one:
   
   mv /var/svn/repo_name /var/svn/repo_name-old
4. Install the new version of subversion.
5. Create a new repository:
   
   svnadmin create /var/svn/repo-name

Backing up your repository

• Shut down svnserve, Apache, and anything else that might be accessing the repository:
  
  svc -d /service/apache
• Dump a backup of the repository:
  • Uncompressed:
    
    svnadmin dump /var/svn/repo_name > dumpfile.txt
  • Compressed:
    
    svnadmin dump /var/svn/repo_name | gzip -9 > dumpfile.gz
  • Compressed, with a datestamp:
    
    svnadmin dump /var/svn/repo_name | gzip -9 > `date "+dumpfile_%Y-%m-%d_%H:%M:%S.gz"`
• Load a database dump:

http://ariejan.net/2007/07/04/how-to-resolve-subversion-conflicts/

• Scrap your local changes
  
  svn revert MYFILE
svn update MYFILE
• Keep your changes and scrap the other person's
  An ls command in the directory will show 4 files related to the one in conflict:
  • MYFILE – the original with markers
  • MYFILE.mine – your version
  • MYFILE.r5 – the original your worked with
  • MYFILE.r6 – the most update version from your colleague

http://hivelogic.com/articles/view/svn_on_os_x
http://www.nearinfinity.com/blogs/scott_leberknight/building_subversion_svn_1_4.html

Creating a branch

Switching a Working Copy

We've been recommending that you use Subversion to manage your Drupal site, so these instructions are geared towards using it to upgrade.

The instructions also presume that your site can be taken offline during the upgrading process. If you've have a site that you can't take offline while the process is completed, you've got a whole other set of complicated issues to deal with!

These instructions were written based on upgrading Drupal 6.14 to Drupal 6.15.

Prepare the current site

Installing a module with Piston

Create the Subversion project:

Create the Trac project: