Parsing explicitly space-padded format specifiers appears broken

[Joey9801]

Hi,

It looks like a recent change to Chrono has broken parsing of the %e/%_d format specifiers ("Same as %d but space-padded"). Rather than expecting a space padding character, the various strptime-like methods now return a Chrono(ParseError(Invalid)) error.

The following repro works as I would expect when built against chrono 0.4.24, and fails against chrono 0.4.25.

use chrono::{FixedOffset, DateTime, TimeZone};

fn main() {
    let s = "Mon Apr  3 22:32:00 BST 2023";
    let fmt = "%a %b %e %T %Z %Y";
    let offset = FixedOffset::east_opt(3600).unwrap();

    let parsed = offset.datetime_from_str(s, fmt).unwrap();
    let expected = offset.with_ymd_and_hms(2023, 4, 3, 22, 32, 0).unwrap();

    assert_eq!(expected, parsed);
}

The changes in #807 look suspiciously related to this issue, though I am not familiar enough with this codebase to know exactly what the issue is.

Many thanks,
Joe

[djc]

#807 was not merged into the 0.4.x branch directly, but it's possible some of those changes made it into 0.4.25 via a backport.

[pitdicker]

Oops, that would be my fault. Should we reverse that?
Or do we want to work an proper support for padding (currently the format specifiers for padding are fully ignored when parsing)?

[djc]

Can you submit a PR to revert? Can try to get out a 0.4.26 tonight.

[Joey9801]

I can confirm that the revert has fixed this issue for me in 0.4.26. Thank you so much @djc and @pitdicker for the incredibly speedy response!

Joe

[jtmoon79]

FYI I'm still planning to look into this in-depth, as this should have been caught by the tests. I just haven't had the opportunity to sit down for an extended period. I hope to do so soon.