Subversion refactor trunk and still be able to merge changes to old branches

What are the best practices in the situation where you refactor trunk in svn but cannot apply the refactor to older branches, yet you still need to be able to svn merge bugfixes from trunk to the branches?

To ask the question more specifically (if it helps - if you can answer the above, then feel free to ignore):

We want to move to Maven going forward, but we still need to maintain old releases - they cannot be touched except with customer sanctioned changes and bugfixes.

So, we need to refactor our folder structures around in trunk to get it as per maven - src/main/java, src/main/webapp etc (its currently a WTP project - src, WebContent instead of above).

But then going forward, we still need to be able to svn merge to the older branches which will still be in the old folder structure.

Is this possible? What are the best practices?

I know we can apply changes to trunk, and then also apply the changes to the branch manually, but this will result in a lot of pain for developers which we want to avoid.

Apologies if this is already answered or is obvious (I would have thought it would be, I feel 开发者_如何学JAVAlike I'm asking an obvious question!)

Thanks in advance, Justin

If you move things around you can still use svn merge, but not straight on. SVN merge does not track moved files.

At the lowest level you can merge on a per file basis, but if you move complete subdirectories you can merge each "untouched" subdirectories at once. There is some more steps involved and you need to track manually where things has been moved.