I noticed that when I used
@List = <$config{'root'}>
to get a list of filenames from a root directory, then acted on that list, filenames with spaces were handled badly.
So I hacked /lib/File/DosGlob.pm around line 155 to be:
@pat = Text::ParseWords::parse_line('\t+',0,$pat);
instead of s+ . And it seems to work well.