When a Subversion-client do not filter characters in filenames properly, it may result in :
I. Client stops working while committing, resulting in a broken checkout of repository. (And a half done commit results in not having a overview of the files.)
II. Writing files to repository which cannot be distributed, results in broken repository. (And it is hard to purge files from a subversion repository.)
III. A broken repository, then again, results in a broken client checkout. (And you have to clean up the client too.)
If you have done all these awful steps, you dont want to do them again.
If you need to clean up the filenames, i wrote a small program that takes care of all the restricted filename letters and names on Windows, OSX and Linux.
Please feel free to grab it, its under the GNU GPL.