--- a/bin/once	Mon Jan 04 13:33:53 2016 +0100
+++ b/bin/once	Mon Jan 04 13:34:33 2016 +0100
@@ -153,6 +153,7 @@
         my $filename = do {
 	# FIXME: should we allow backslashes in filenames? It's totally legal for *nix,
 	# but may confuse win* users, for now we play safe and convert \ to _
+	# OTOH, then we should convert other problematic chars too.
             $file =~ tr /\\/\//;	# convert \ to /
 	    $file =~ s/.*\///;          # poor man's basename
             $file =~ /(.*)/;