Magento version upgrade in SVN

I have a Magento Enterprise Edition install in a repository, client's site is running, all is well. Now I want to upgrade this client to a new version of Magento, but the only help that EE gives me for upgrades is to delete the entire app/code/core directory and 开发者_Python百科move the new files in.

This is, to say the least, non-optimal.

Any good thoughts on how I can do the change while preserving my SVN history cleanly?

Thanks, Joe

A very good way of managing this situation, using an external library in a project under SVN, is described in the book Version Control with Subversion, in the section titled Vendor Branches. It's also available on-line:

http://svnbook.red-bean.com/en/1.1/ch07s05.html