Import sorting breaks with long paths

[lovesegfault]

Given the following code:

use zsome_other_crate_with_long_name::baz_baz_baz_baz_baz_baz_baz::baz_baz_baz_baz_baz::BazBazBazBazBaz;
use ayet_another_crate_with_a_really_big_name::bar_bar_bar_bar_bar_bar_bar_bar_bar::bar_bar_bar_bar_bar::BarBarBarBarBarBarBarBarBar;

playground link

I would expect rustfmt to reorder those two, resulting in:

use ayet_another_crate_with_a_really_big_name::bar_bar_bar_bar_bar_bar_bar_bar_bar::bar_bar_bar_bar_bar::BarBarBarBarBarBarBarBarBar;
use zsome_other_crate_with_long_name::baz_baz_baz_baz_baz_baz_baz::baz_baz_baz_baz_baz::BazBazBazBazBaz;

However, if you test it, rustfmt leaves the ordering unchanged, which, I believe, is a bug.

[lovesegfault]

If you configure max_width to a large number, it works as expected.

[ytmimi]

@lovesegfault thanks for reaching out, and for digging into this a little yourself.

This is indeed a max_width issue. max_width is a hard constraint for rustfmt, and I don't think that's going to change anytime soon. Unfortunately this doesn't seem to be actionable at this time so I'm going to go ahead and close this.

[lovesegfault]

@ytmimi I don't think solving this necessarily requires fiddling with max_width though, right?

For example, it could attempt to format that long import as:

use ayet_another_crate_with_a_really_big_name::{
    bar_bar_bar_bar_bar_bar_bar_bar_bar::{
        bar_bar_bar_bar_bar::BarBarBarBarBarBarBarBarBar;
    }
};

To keep it under max_width?

[ytmimi]

I believe something similar was proposed in #4746, specifically #4746 (comment)