Hello, One more addition to my previous message: in SVNKit we've fixed this problem by making commit and wc-to-repos copy operation not to commit file external even when it is modified, unless it is explicitly specified as a file to commit or as a copy source.
-- Alexander Kitaev, TMate Software, http://svnkit.com/ - Java [Sub]Versioning Library! http://sqljet.com/ - Java SQLite Library!