+
+ // when m_dirs is empty it may mean either that we have no path at all or
+ // that our path is '/', i.e. the root directory
+ //
+ // we use m_relative to distinguish between these two cases, it will be
+ // TRUE in the former and FALSE in the latter
+ //
+ // NB: the path is not absolute just because m_relative is FALSE, it still
+ // needs the drive (i.e. volume) in some formats (Windows)