Recognize doesn't work with tuple

[RunBolt]

Environment

nom = "8.0.0"

Problem

When using recognize((satisfy(|c| c.is_uppercase()), alpha0)) parser, this produces only the first character of Hello.

        #[test]
        fn test_name() {
            let testing = || -> IResult<_, _> {
                recognize((satisfy(|c: char| c.is_uppercase()), alpha0)).parse("Hello")
            };
            let (rest, name) = testing().unwrap();
            println!("Name: {name:?}");
            println!("Rest: {rest:?}");
        }

This prints:

Name: "H"
Rest: ""

When I change it to use just the inner tuple: (satisfy(|c: char| c.is_uppercase()), alpha0)

Name: ('H', "ello")
Rest: ""

[reddaemon]

I was able to reproduce this on nom 8.0.0.

The issue appears to be caused by the &str implementation of split_at_position_complete: when the parser consumes the rest of the input, it returns an empty slice pointing to the beginning of the string instead of the end. This makes Offset report the wrong consumed length, which causes recognize to return only "H" instead of "Hello".

Interestingly, this seems to have already been fixed on main by #1811 (51c3c4e), which changed the &str implementation to use take_split(self.input_len()). The regression test added there covers the same underlying issue.

So it looks like #1887 is fixed on main, but the fix has not yet made it into a released version.

As a temporary workaround, the fixed commit can be used directly from git:

[patch.crates-io]
nom = { git = "https://github.com/rust-bakery/nom", rev = "51c3c4e44fa78a8a09b413419372b97b2cc2a787" }

This works as a temporary workaround, although a proper crates.io release would of course be preferable.