Subversion adding unversioned project files to working copy

I have a project, calendars, that has been worked on by a number of different developers. I decided to place the project unde开发者_如何学编程r version control using Subversion, but in the meantime these different developers continued to work on their unversioned files independently of me.

Developer A      Developer B       Me

header.h         header.h          header.h
timer.c          timer.c           timer.c
timezones.c                        timezones.c
calendars.c                        .svn

My question is, how do I bring their changes in line with mine, where the repository is on a remote server?

My thinking is that Developers A and B would have to check out from the repository, but then how would they merge their own files with the ones they have checked out before then committing back to the repository?

Because their projects are not versioned they must merge changes manually. It is unavoidable, but it is only done once. It should be done as soon as possible.

• rename current project X to X_old
• checkout X
• compare each file individually (WinMerge is good for that), and bring changes from X_old to X, taking care of each different line in each file
• in the end commit changes

Developers should bring their projects to version control sequentially to minimize conflicts.