multiple values and occurrences are not correctly counted / grouped for positionals

[epage]

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• I have searched the discussions
• I have searched the open and rejected issues

Rust Version

rustc 1.57.0 (f1edd0429 2021-11-29)

Clap Version

3.1.13

Minimal reproducible code

#[test]
fn values_per_occurrence_positional() {
    let mut a = Command::new("test").arg(
        Arg::new("pos")
            .number_of_values(2)
            .multiple_occurrences(true),
    );

    let m = a.try_get_matches_from_mut(vec!["myprog", "val1", "val2"]);
    let m = match m {
        Ok(m) => m,
        Err(err) => panic!("{}", err),
    };
    assert_eq!(
        m.get_many::<String>("pos")
            .unwrap()
            .map(|v| v.as_str())
            .collect::<Vec<_>>(),
        ["val1", "val2"]
    );
    assert_eq!(m.occurrences_of("pos"), 1);

    let m = a.try_get_matches_from_mut(vec!["myprog", "val1", "val2", "val3", "val4"]);
    let m = match m {
        Ok(m) => m,
        Err(err) => panic!("{}", err),
    };
    assert_eq!(
        m.get_many::<String>("pos")
            .unwrap()
            .map(|v| v.as_str())
            .collect::<Vec<_>>(),
        ["val1", "val2", "val3", "val4"]
    );
    assert_eq!(m.occurrences_of("pos"), 2); // Fails, we don't recognize this as two occurrences
}

#[test]
fn positional_parser_advances() {
    let m = Command::new("multiple_values")
        .arg(Arg::new("pos1").number_of_values(2))
        .arg(Arg::new("pos2").number_of_values(2))
        .try_get_matches_from(vec!["myprog", "val1", "val2", "val3", "val4"]);

    assert!(m.is_ok(), "{}", m.unwrap_err());
    let m = m.unwrap();

    assert_eq!(m.occurrences_of("pos1"), 1);
    assert_eq!(
        m.get_many::<String>("pos1")
            .unwrap()
            .map(|v| v.as_str())
            .collect::<Vec<_>>(),
        ["val1", "val2"]
    );

    assert_eq!(m.occurrences_of("pos2"), 1);
    assert_eq!(
        m.get_many::<String>("pos2")
            .unwrap()
            .map(|v| v.as_str())
            .collect::<Vec<_>>(),
        ["val3", "val4"]
    );
}

Steps to reproduce the bug with the above code

Inject those tests into clap

Actual Behaviour

The first test will report groups correctly but will also report an occurrence per value, contradicting the documentation. In a change I'm working on, it will instead report one occurrence regardless of how many occurrences there should be

The second test is invalid because we don't stop parsing multiple values once we've hit the cap, so we disallow it in a debug assert

Expected Behaviour

Both pass

Additional Context

No response

Debug Output

No response

[epage]

Closing because of #3772