I think I agree. The C -> cpp should IMHO happen at the same time for the whole tree i.e. after you are done with the name changing (with which I fully agree).
I do not want to rename files twice and my current approach is to propose changes directory by directory. Consider that .C ==> .cpp is not only "svn rename", but also \file file.C and other changes in comments and Makefiles, renaming in two steps does not make sense to me. Cheers, Bo
