- only accept ASCII-encoded .dirindex files (this is guaranteed to work
fine "everywhere");
- reject .dirindex files with a 'path' entry that contains a backslash
or starts with a slash;
- reject .dirindex files with a 'path' entry that contains a '..'
component;
- reject .dirindex files with an 'f', 'd' or 't' entry whose name field
contains a slash or a backslash;
- reject .dirindex files with an 'f', 'd' or 't' entry whose name field
is '..';
- add comment lines (starting with '#') in the sample good .dirindex
file used by unit tests.
