ls: Limit value of --width to maximum value if overflowing

[Skryptonyte]

This change will clamp --width value to u16::MAX if the number passed is too large. The present behaviour results in invalid line width error. This lets gnu/tests/ls/w-option.sh progress a bit further till the last test.

The actual correct behaviour would have been to set the limit to u64::MAX as per the GNU test but all the logic related to formatting seems to be heavily reliant on u16 values, including one crate terminal_size and that would probably take a while for me to sift through. In all practical cases, this should be indistinguishable unless you are printing on a billboard maybe.

[sylvestre]

what about moving this into a function like:

fn parse_width(x: &str, is_octal: bool) -> Result<u16, LsError> {
    let parse_result = if x.starts_with('0') && x.len() > 1 {
        u16::from_str_radix(x, 8)
    } else {
        x.parse::<u16>()
    };

    match parse_result {
        Ok(v) => Ok(v),
        Err(err) => match err {
            ParseIntError::Overflow => {
                eprintln!("The width value provided is too large. It has been set to the maximum possible value.");
                Ok(u16::MAX)
            },
            _ => Err(LsError::InvalidLineWidth(x.into()).into()),
        }
    }
}

[Skryptonyte]

Yeah, I thought what I did looked pretty ugly. This should look much cleaner now.

[sylvestre]

indeed, fails a bit later now:

2023-07-12T18:46:36.0409766Z FAIL: tests/ls/w-option
2023-07-12T18:46:36.0409857Z =======================
2023-07-12T18:46:36.0409864Z 
2023-07-12T18:46:36.0410127Z ls: invalid line width: '-1'
2023-07-12T18:46:36.0410299Z ls: invalid line width: '08'
2023-07-12T18:46:36.0410384Z a
2023-07-12T18:46:36.0410466Z b
2023-07-12T18:46:36.0410615Z �[1;32ma�[0m  b  exp  out
2023-07-12T18:46:36.0410813Z --- exp	2023-07-12 18:36:23.974039937 +0000
2023-07-12T18:46:36.0410981Z +++ out	2023-07-12 18:36:23.978039942 +0000
2023-07-12T18:46:36.0411113Z @@ -1 +1,2 @@
2023-07-12T18:46:36.0411225Z -a  b
2023-07-12T18:46:36.0411309Z +a
2023-07-12T18:46:36.0411391Z +b
2023-07-12T18:46:36.0411590Z FAIL tests/ls/w-option.sh (exit status: 1)