Merging Structural Changes

Recently, a project I’m working on set out to reinvent their build process, migrating from a mass of poorly-written Ant scripts to Maven and reorganizing their source tree in the process. The development process is based on having a branch per client, so there is a lot of ongoing development on the original layout for clients that haven’t been migrated yet. We discovered that our version control tool, Subversion, is unable to merge the changes between client branches on the old structure and the trunk on the new structure automatically.

Curiousity piqued, I cooked up a script that reproduces the problem and performs the merge from various directions to examine the results. Subversion, sadly, performed dismally: none of the merge scenarios tested retained content changes when merging structural changes to the same files.
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