add_subdirectory(foo)
fails with an error if the foo subdir doesn't exist at all,
but simply does nothing if the foo subdir exists and has no CMakeListst.txt
Is this intentional? It seems a bit inconsistent.

-- 
David Faure, faure at kde.org, sponsored by Trolltech to work on KDE,
Konqueror (http://www.konqueror.org), and KOffice (http://www.koffice.org).