[dir] use nullptr and const_cast<> in TDirectoryFile
[dir] use nullptr and const_cast<> in TDirectoryFile
olifre/root,karies/root,karies/root,olifre/root,olifre/root,karies/root,karies/root,root-mirror/root,olifre/root,karies/root,root-mirror/root,karies/root,root-mirror/root,karies/root,root-mirror/root,olifre/root,root-mirror/root,olifre/root,olifre/root,karies/root,karies/root,karies/root,olifre/root,olifre/root,root-mirror/root,root-mirror/root,karies/root,olifre/root,root-mirror/root,root-mirror/root,root-mirror/root,root-mirror/root,olifre/root