We have 4 inputs:

- u7z.simple.input

    Simplest input: no abnormalities.
    (One line has a filename with spaces in it.)

- u7z.missing-date.input

    Date field is missing (see #2707).

- u7z.missing-size-and-date.input

    Size field is missing, and in some rows the date is missing too (see #2707).

- u7z.complex.input

    Downloaded from #2707. It's 'list.txt' plus three bottom lines from
    'listing2.txt'. It demonstrates all the above: missing date, missing
    uncompressed and compressed size.


Output files must be constant. Therefore in our '*.env_var' files we
define a command that sets missing dates to some fixed date (instead of
being the archive's date).