Add a protection for empty directories (e.g. not containing any key). Solves the bug #94028, TBrowser crash trying to browse sub-root-directories in memory (https://savannah.cern.ch/bugs/?94028)
Add a protection for empty directories (e.g. not containing any key). Solves the bug #94028, TBrowser crash trying to browse sub-root-directories in memory (https://savannah.cern.ch/bugs/?94028)


git-svn-id: acec3fd5b7ea1eb9e79d6329d318e8118ee2e14f@43949 27541ba8-7e3a-0410-8455-c3a389f83636

bbockelm/root-historical,bbockelm/root-historical,bbockelm/root-historical,bbockelm/root-historical,bbockelm/root-historical,bbockelm/root-historical,bbockelm/root-historical