:reflow repeatedly doesn't produce same results

[A-Walrus]

Summary

I would expect that running :reflow on a selection and then running it again would have no effect the second time, but this is not always the case. For example with the file https://github.com/red-hat-storage/ocs-osd-deployer/blob/main/controllers/managedocs_controller.go, running reflow repeatedly will continue to change it.

I believe this is an upstream bug with the textwrap crate.
Running this code will print constantly change text length

fn main() {
    let mut text = std::fs::read_to_string("managedocs_controller.go").unwrap();
    loop {
        text = textwrap::refill(&text, 79);
        dbg!(text.len());
    }
}

Output

[src/main.rs:5] text.len() = 66194
[src/main.rs:5] text.len() = 65970
[src/main.rs:5] text.len() = 65924
[src/main.rs:5] text.len() = 65931
[src/main.rs:5] text.len() = 65938
[src/main.rs:5] text.len() = 65945
[src/main.rs:5] text.len() = 65952
[src/main.rs:5] text.len() = 65959
[src/main.rs:5] text.len() = 65966
[src/main.rs:5] text.len() = 65973
[src/main.rs:5] text.len() = 65980
[src/main.rs:5] text.len() = 65987
[src/main.rs:5] text.len() = 65994
[src/main.rs:5] text.len() = 66001
[src/main.rs:5] text.len() = 66008
[src/main.rs:5] text.len() = 66015
[src/main.rs:5] text.len() = 66022
[src/main.rs:5] text.len() = 66029
[src/main.rs:5] text.len() = 66036
[src/main.rs:5] text.len() = 66043
[src/main.rs:5] text.len() = 66050
[src/main.rs:5] text.len() = 66057
[src/main.rs:5] text.len() = 66064
[src/main.rs:5] text.len() = 66071
[src/main.rs:5] text.len() = 66078
[src/main.rs:5] text.len() = 66085
[src/main.rs:5] text.len() = 66092
[src/main.rs:5] text.len() = 66099
[src/main.rs:5] text.len() = 66106
[src/main.rs:5] text.len() = 66113
[src/main.rs:5] text.len() = 66120
[src/main.rs:5] text.len() = 66127
[src/main.rs:5] text.len() = 66126
[src/main.rs:5] text.len() = 66119
[src/main.rs:5] text.len() = 66126

and so on...

Reproduction Steps

asciinema

In order to reproduce have to check out PR #3733 which fixes an unrelated bug with :reflow panicking

I tried this:

1. hx managedocs_controller.go (file from the link above)
2. select all with %
3. :reflow
4. :reflow again, notice that this changes things again

I expected this to happen:
No changes on the second reflow

Instead, this happened:
Things change on the second reflow (line count goes from 960 to 952)

Helix log

Empty

Platform

Linux

Terminal Emulator

Kitty

Helix Version

PR #3733